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  • richardmitnick 8:08 pm on March 15, 2023 Permalink | Reply
    Tags: "Where Did Earth’s Water Come From? Not Melted Meteorites According to Scientists", A UMD-led study offers new insight into the extraterrestrial origins of our lakes and rivers and oceans., After analyzing achondrite meteorite samples researchers discovered that water comprised less than two millionths of their mass., , Because these meteorites fell to Earth only recently this experiment was the first time anyone had ever measured their volatiles., , , Exoplanet research, , It has yet to be determined what types of objects could have carried water across the solar system., , The team of researchers analyzed seven melted-or achondrite-meteorites that crashed into Earth billions of years after splintering from at least five planetesimals., , Water makes up 71% of Earth’s surface but no one knows how or when such massive quantities of water arrived on Earth.   

    From The College of Computer Mathematics and Natural Sciences At The University of Maryland : “Where Did Earth’s Water Come From? Not Melted Meteorites According to Scientists” 

    From The College of Computer Mathematics and Natural Sciences


    The University of Maryland

    Emily Nunez

    A UMD-led study offers new insight into the extraterrestrial origins of our lakes and rivers and oceans.

    Water makes up 71% of Earth’s surface but no one knows how or when such massive quantities of water arrived on Earth.

    A new study published in the journal Nature [below] brings scientists one step closer to answering that question. Led by University of Maryland Assistant Professor of Geology Megan Newcombe, researchers analyzed melted meteorites that had been floating around in space since the solar system’s formation 4 1/2 billion years ago. They found that these meteorites had extremely low water content—in fact, they were among the driest extraterrestrial materials ever measured.

    These results, which let researchers rule them out as the primary source of Earth’s water, could have important implications for the search for water—and life—on other planets. It also helps researchers understand the unlikely conditions that aligned to make Earth a habitable planet.

    “We wanted to understand how our planet managed to get water because it’s not completely obvious,” Newcombe said. “Getting water and having surface oceans on a planet that is small and relatively near the sun is a challenge.”

    The dashed white line in this illustration shows the boundary between the inner solar system and outer solar system, with the asteroid belt positioned roughly in between Mars and Jupiter. A bubble near the top of the image shows water molecules attached to a rocky fragment, demonstrating the kind of object that could have carried water to Earth. Credit: Jack Cook/Woods Hole Oceanographic Institution.

    The team of researchers analyzed seven melted, or achondrite, meteorites that crashed into Earth billions of years after splintering from at least five planetesimals—objects that collided to form the planets in our solar system. In a process known as melting, many of these planetesimals were heated up by the decay of radioactive elements in the early solar system’s history, causing them to separate into layers with a crust, mantle and core.

    Because these meteorites fell to Earth only recently this experiment was the first time anyone had ever measured their volatiles. UMD geology graduate student Liam Peterson used an electron microprobe to measure their levels of magnesium, iron, calcium and silicon, then joined Newcombe at the Carnegie Institution for Science’s Earth and Planets Laboratory to measure their water contents with a secondary ion mass spectrometry instrument.

    “The challenge of analyzing water in extremely dry materials is that any terrestrial water on the sample’s surface or inside the measuring instrument can easily be detected, tainting the results,” said study co-author Conel Alexander, a scientist at the Carnegie Institution for Science.

    To reduce contamination, researchers first baked their samples in a low-temperature vacuum oven to remove any surface water. Before the samples could be analyzed in the secondary ion mass spectrometer, the samples had to be dried out once again.

    “I had to leave the samples under a turbo pump—a really high-quality vacuum—for more than a month to draw down the terrestrial water enough,” Newcombe said.

    Some of their meteorite samples came from the inner solar system, where Earth is located and where conditions are generally assumed to have been warm and dry. Other rarer samples came from the colder, icier outer reaches of our planetary system. While it was generally thought that water came to Earth from the outer solar system, it has yet to be determined what types of objects could have carried that water across the solar system.

    “We knew that plenty of outer solar system objects were differentiated, but it was sort of implicitly assumed that because they were from the outer solar system, they must also contain a lot of water,” said Sune Nielsen, a study co-author and geologist at the Woods Hole Oceanographic Institution. “Our paper shows this is definitely not the case. As soon as meteorites melt, there is no remaining water.”

    After analyzing the achondrite meteorite samples researchers discovered that water comprised less than two millionths of their mass. For comparison, the wettest meteorites—a group called carbonaceous chondrites—contain up to about 20% of water by weight, or 100,000 times more than the meteorite samples studied by Newcombe and her co-authors.

    This means that the heating and melting of planetesimals leads to near-total water loss, regardless of where these planetesimals originated in the solar system and how much water they started out with. Newcombe and her co-authors discovered that, contrary to popular belief, not all outer solar system objects are rich in water. This led them to conclude that water was likely delivered to Earth via unmelted, or chondritic, meteorites.

    Newcombe said their findings have applications beyond geology. Scientists of many disciplines—and especially exoplanet researchers—are interested in the origin of Earth’s water because of its deep connections with life.

    “Water is considered to be an ingredient for life to be able to flourish, so as we’re looking out into the universe and finding all of these exoplanets, we’re starting to work out which of those planetary systems could be potential hosts for life,” Newcombe said. “In order to be able to understand these other solar systems, we want to understand our own.”


    From the science paper

    The timing of delivery and the types of body that contributed volatiles to the terrestrial planets remain highly debated [1*],[2]. For example, it is unknown if differentiated bodies, such as that responsible for the Moon-forming giant impact, could have delivered substantial volatiles [3],[4] or if smaller, undifferentiated objects were more probable vehicles of water delivery [5],[6],[7]. Here we show that the water contents of minerals in achondrite meteorites (mantles or crusts of differentiated planetesimals) from both the inner and outer portions of the early Solar System are ≤2 μg g−1 H2O. These are among the lowest values ever reported for extraterrestrial minerals. Our results demonstrate that differentiated planetesimals efficiently degassed before or during melting. This finding implies that substantial amounts of water could only have been delivered to Earth by means of unmelted material.
    *See the science paper for cited references.

    Degassing of early-formed planetesimals restricted water delivery to Earth.


    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    About The University of Maryland College of Computer Mathematics and Natural Sciences

    The thirst for new knowledge is a fundamental and defining characteristic of humankind. It is also at the heart of scientific endeavor and discovery. As we seek to understand our world, across a host of complexly interconnected phenomena and over scales of time and distance that were virtually inaccessible to us a generation ago, our discoveries shape that world. At the forefront of many of these discoveries is the College of Computer, Mathematical, and Natural Sciences (CMNS).

    CMNS is home to 12 major research institutes and centers and to 10 academic departments: astronomy, atmospheric and oceanic science, biology, cell biology and molecular genetics, chemistry and biochemistry, computer science, entomology, geology, mathematics, and physics.

    Our Faculty

    Our faculty are at the cutting edge over the full range of these disciplines. Our physicists fill in major gaps in our fundamental understanding of matter, participating in the recent Higgs boson discovery, and demonstrating the first-ever teleportation of information between atoms. Our astronomers probe the origin of the universe with one of the world’s premier radio observatories, and have just discovered water on the moon. Our computer scientists are developing the principles for guaranteed security and privacy in information systems.

    Our Research

    Driven by the pursuit of excellence, the University of Maryland has enjoyed a remarkable rise in accomplishment and reputation over the past two decades. By any measure, Maryland is now one of the nation’s preeminent public research universities and on a path to become one of the world’s best. To fulfill this promise, we must capitalize on our momentum, fully exploit our competitive advantages, and pursue ambitious goals with great discipline and entrepreneurial spirit. This promise is within reach. This strategic plan is our working agenda.

    The plan is comprehensive, bold, and action oriented. It sets forth a vision of the University as an institution unmatched in its capacity to attract talent, address the most important issues of our time, and produce the leaders of tomorrow. The plan will guide the investment of our human and material resources as we strengthen our undergraduate and graduate programs and expand research, outreach and partnerships, become a truly international center, and enhance our surrounding community.

    Our success will benefit Maryland in the near and long term, strengthen the State’s competitive capacity in a challenging and changing environment and enrich the economic, social and cultural life of the region. We will be a catalyst for progress, the State’s most valuable asset, and an indispensable contributor to the nation’s well-being. Achieving the goals of Transforming Maryland requires broad-based and sustained support from our extended community. We ask our stakeholders to join with us to make the University an institution of world-class quality with world-wide reach and unparalleled impact as it serves the people and the state of Maryland.

    Our researchers are also at the cusp of the new biology for the 21st century, with bioscience emerging as a key area in almost all CMNS disciplines. Entomologists are learning how climate change affects the behavior of insects, and earth science faculty are coupling physical and biosphere data to predict that change. Geochemists are discovering how our planet evolved to support life, and biologists and entomologists are discovering how evolutionary processes have operated in living organisms. Our biologists have learned how human generated sound affects aquatic organisms, and cell biologists and computer scientists use advanced genomics to study disease and host-pathogen interactions. Our mathematicians are modeling the spread of AIDS, while our astronomers are searching for habitable exoplanets.

    Our Education

    CMNS is also a national resource for educating and training the next generation of leaders. Many of our major programs are ranked among the top 10 of public research universities in the nation. CMNS offers every student a high-quality, innovative and cross-disciplinary educational experience that is also affordable. Strongly committed to making science and mathematics studies available to all, CMNS actively encourages and supports the recruitment and retention of women and minorities.

    Our Students

    Our students have the unique opportunity to work closely with first-class faculty in state-of-the-art labs both on and off campus, conducting real-world, high-impact research on some of the most exciting problems of modern science. 87% of our undergraduates conduct research and/or hold internships while earning their bachelor’s degree. CMNS degrees command respect around the world, and open doors to a wide variety of rewarding career options. Many students continue on to graduate school; others find challenging positions in high-tech industry or federal laboratories, and some join professions such as medicine, teaching, and law.

    U Maryland Campus

    The University of Maryland is a public land-grant research university. Founded in 1856, The University of Maryland is the flagship institution of the University System of Maryland. It is also the largest university in both the state and the Washington metropolitan area, with more than 41,000 students representing all fifty states and 123 countries, and a global alumni network of over 388,000. Its twelve schools and colleges together offer over 200 degree-granting programs, including 92 undergraduate majors, 107 master’s programs, and 83 doctoral programs. The University of Maryland is a member of The Association of American Universities and competes in intercollegiate athletics as a member of the Big Ten Conference.

    The University of Maryland’s proximity to the nation’s capital has resulted in many research partnerships with the federal government; faculty receive research funding and institutional support from agencies such as The National Institutes of Health (US), The National Aeronautics and Space Administration, The National Institute of Standards and Technology, The Food and Drug Administration, The National Security Agency, and The Department of Homeland Security. It is classified among “R1: Doctoral Universities – Very high research activity” and is labeled a “Public Ivy”, denoting a quality of education comparable to the private Ivy League. The University of Maryland is ranked among the top 100 universities both nationally and globally by several indices, including its perennially top-ranked criminology and criminal justice department.

    In 2016, the University of Maryland-College Park and The University of Maryland- Baltimore formalized their strategic partnership after their collaboration successfully created more innovative medical, scientific, and educational programs, as well as greater research grants and joint faculty appointments than either campus has been able to accomplish on its own. According to The National Science Foundation, the university spent a combined $1.1 billion on research and development in 2019, ranking it 14th overall in the nation and 8th among all public institutions. As of 2021, the operating budget of the University of Maryland is approximately $2.2 billion.

    On March 6, 1856, the forerunner of today’s University of Maryland was chartered as the Maryland Agricultural College. Two years later, Charles Benedict Calvert (1808–1864), a future U.S. Representative (Congressman) from the sixth congressional district of Maryland, 1861–1863, during the American Civil War and descendant of the first Lord Baltimores, colonial proprietors of the Province of Maryland in 1634, purchased 420 acres (1.7 km^2) of the Riversdale Mansion estate nearby today’s College Park, Maryland. Later that year, Calvert founded the school and was the acting president from 1859 to 1860. On October 5, 1859, the first 34 students entered the Maryland Agricultural College. The school became a land grant college in February 1864.

    Following the Civil War, in February 1866, the Maryland legislature assumed half ownership of the school. The college thus became in part a state institution. By October 1867, the school reopened with 11 students. In 1868, the former Confederate admiral Franklin Buchanan was appointed President of the school, and in his tenure of just over a year, he reorganized it, established a system of strict economy in its business transactions, applied some of its revenues for the paying off of its debts, raised its standards, and attracted patrons through his personal influence: enrollment grew to 80 at the time of his resignation, and the school’s debt was soon paid off. In 1873, Samuel Jones, a former Confederate Major General, became president of the college.

    Twenty years later, the federally funded Agricultural Experiment Station was established there. During the same period, state laws granted the college regulatory powers in several areas—including controlling farm disease, inspecting feed, establishing a state weather bureau and geological survey, and housing the board of forestry. Morrill Hall (the oldest instructional building still in use on campus) was built the following year.

    The state took control of the school in 1916, and the institution was renamed Maryland State College. That year, the first female students enrolled at the school. On April 9, 1920, the college became part of the existing University of Maryland, replacing St. John’s College, Annapolis as the university’s undergraduate campus. In the same year, the graduate school on the College Park campus awarded its first PhD degrees and the university’s enrollment reached 500 students. In 1925 the university was accredited by The Association of American Universities.

    By the time the first black students enrolled at the university in 1951, enrollment had grown to nearly 10,000 students—4,000 of whom were women. Prior to 1951, many black students in Maryland were enrolled at The University of Maryland-Eastern Shore.

    In 1957, President Wilson H. Elkins made a push to increase academic standards at the university. His efforts resulted in the creation of one of the first Academic Probation Plans. The first year the plan went into effect, 1,550 students (18% of the total student body) faced expulsion.

    On October 19, 1957, Queen Elizabeth II of the United Kingdom attended her first and only college football game at the University of Maryland after expressing interest in seeing a typical American sport during her first tour of the United States. The Maryland Terrapins beat the North Carolina Tar Heels 21 to 7 in the historical game now referred to as “The Queen’s Game”.

    Phi Beta Kappa established a chapter at UMD in 1964. In 1969, the university was elected to The Association of American Universities. The school continued to grow, and by the fall of 1985 reached an enrollment of 38,679. Like many colleges during the Vietnam War, the university was the site of student protests and had curfews enforced by the National Guard.

    In a massive restructuring of the state’s higher education system in 1988, the school was designated as the flagship campus of the newly formed University of Maryland System (later changed to the University System of Maryland in 1997), and was formally named the University of Maryland-College Park. All of the five campuses in the former network were designated as distinct campuses in the new system. However, in 1997 the Maryland General Assembly passed legislation allowing the University of Maryland-College Park to be known simply as The University of Maryland, recognizing the campus’ role as the flagship institution of the University System of Maryland.

    The other University System of Maryland institutions with the name “University of Maryland” are not satellite campuses of the University of Maryland-College Park. The University of Maryland-Baltimore, is the only other school permitted to confer certain degrees from the “University of Maryland”.

    In 1994, the National Archives at College Park completed construction and opened on a parcel of land adjoining campus donated by the University of Maryland, after lobbying by President William Kirwan and congressional leaders to foster academic collaboration between the institutions.

    In 2004, the university began constructing the 150-acre (61 ha) “M Square Research Park,” which includes facilities affiliated with The Department of Defense , Food and Drug Administration, and the new National Center for Weather and Climate Prediction, affiliated with The National Oceanic and Atmospheric Administration. In May 2010, ground was broken on a new $128-million, 158,068-square-foot (14,685.0 m^2) Physical Science Complex, including an advanced quantum science laboratory.

    The university’s Great Expectations campaign from 2006 to 2012 exceeded $1 billion in private donations.

    The university suffered multiple data breaches in 2014. The first resulted in the loss of over 300,000 student and faculty records. A second data breach occurred several months later. The second breach was investigated by the FBI and Secret Service and found to be done by David Helkowski. Despite the attribution, no charges were filed. As a result of the data breaches, the university offered free credit protection for five years to the students and faculty affected.

    In 2012, the University of Maryland-College Park and the University of Maryland- Baltimore united under the MPowering the State initiative to leverage the strengths of both institutions. The University of Maryland Strategic Partnership Act of 2016 officially formalized this partnership.

    The University of Maryland’s University District Plan, developed in 2011 under President Wallace Loh and the College Park City Council, seeks to make the City of College Park a top 20 college town by 2020 by improving housing and development, transportation, public safety, local pre-K–12 education, and supporting sustainability projects. As of 2018, the university is involved with over 30 projects and 1.5 million square feet of development as part of its Greater College Park Initiative, worth over $1 billion in public-private investments. The university’s vision is to revitalize the campus to foster a dynamic and innovative academic environment, as well as to collaborate with the surrounding neighborhoods and local government to create a vibrant downtown community for students and faculty

    In October 2017, the university received a record-breaking donation of $219.5 million from the A. James & Alice B. Clark Foundation, ranking among the largest philanthropic gifts to a public university in the country.

    As of February 12, 2020, it has been announced that Darryll J. Pines will be the 34th President of the University of Maryland-College Park effective July 1, 2020. Darryll J. Pines is the dean of the A. James Clark School of Engineering and the Nariman Farvardin Professor of Aerospace Engineering since January 2009. Darryll J. Pines has been with the University of Maryland College Park for 25 years since he arrived in 1995 and started as an assistant professor.

    In 2021, the university announced it had achieved its record goal of $1.5 billion raised in donations since 2018 as part of its Fearless Ideas: The Campaign for Maryland for investments in faculty, students, research, scholarships, and capital projects.

    The university hosts “living-learning” programs which allow students with similar academic interests to live in the same residential community, take specialized courses, and perform research in those areas of expertise. An example is the Honors College, which is geared towards undergraduate students meeting high academic requirements and consists of several of the university’s honors programs. The Honors College welcomes students into a community of faculty and undergraduates. The Honors College offers seven living and learning programs: Advanced Cybersecurity Experience for Students, Design Cultures and Creativity, Entrepreneurship and Innovation, Honors Humanities, Gemstone, Integrated Life Sciences, and University Honors.

    Advanced Cybersecurity Experience for Students (ACES), started in 2013, is directed by Michel Cukier and run by faculty and graduate students. ACES students are housed in Prince Frederick Hall and take a 14 credit, two year curriculum that educates future leaders in the field of cybersecurity. ACES also offers a complementary two-year minor in cybersecurity.

    Design Cultures and Creativity (DCC), started in 2009, is directed by artist Jason Farman and run by faculty and graduate students. The DCC program encourages students to explore the relationship between emerging media, society, and creative practices. DCC students are housed in Prince Frederick residence hall together and take a 16 credit, two year interdisciplinary curriculum which culminates in a capstone.

    Entrepreneurship and Innovation Program (EIP) is a living and learning program for Honors College freshmen and sophomores, helping build entrepreneurial mindsets, skill sets, and relationships for the development of solutions to today’s problems. Through learning, courses, seminars, workshops, competitions, and volunteerism, students receive an education in entrepreneurship and innovation. In collaboration with faculty and mentors who have launched new ventures, all student teams develop an innovative idea and write a product plan.

    Honors Humanities is the honors program for beginning undergraduates with interests in the humanities and creative arts. The selective two-year living-learning program combines a small liberal arts college environment with the resources of a large research university.

    Gemstone is a multidisciplinary four-year research program for select undergraduate honors students of all majors. Under guidance of faculty mentors and Gemstone staff, teams of students design, direct and conduct research, exploring the interdependence of science and technology with society.

    Integrated Life Sciences (ILS) is the honors program for students interested in all aspects of biological research and biomedicine. The College of Computer, Mathematical, and Natural Sciences has partnered with the Honors College to create the ILS program, which offers nationally recognized innovations in the multidisciplinary training of life science and pre-medical students. The objective of the ILS experience is to prepare students for success in graduate, medical, dental, or other professional schools.

    University Honors (UH) is the largest living-learning program in the Honors College and allows students the greatest independence in shaping their education. University Honors students are placed into a close-knit community of the university’s faculty and other undergraduates, committed to acquiring a broad and balanced education. Students choose from over 130 seminars exploring interdisciplinary topics in three broad areas: Contemporary Issues and Challenges, Arts and Sciences in Today’s World, and Using the World as a Classroom.

    The College Park Scholars programs are two-year living-learning programs for first- and second-year students. Students are selected to enroll in one of 12 thematic programs: Arts; Business, Society, and the Economy; Environment, Technology, and Economy; Global Public Health; International Studies; Life Sciences; Media, Self, and Society; Public Leadership; Science and Global Change; Science, Discovery, and the Universe; Science, Technology, and Society. Students live in dormitories in the Cambridge Community on North Campus.

    The nation’s first living-learning entrepreneurship program, Hinman CEOs, is geared toward students who are interested in starting their own business. Students from all academic disciplines live together and are provided the resources to explore business ventures.

    The QUEST (Quality Enhancement Systems and Teams) Honors Fellows Program engages undergraduate students from business, engineering, and computer, mathematical, and physical sciences. QUEST Students participate in courses focused on cross-functional collaboration, innovation, quality management, and teamwork. The Department of Civil & Environmental Engineering (CEE) has also been long considered an outstanding engineering division of the university since its inception in 1908.

    Other living-learning programs include: CIVICUS, a two-year program in the College of Behavioral and Social Sciences based on the five principles of civil society; Global Communities, a program that immerses students in a diverse culture (students from all over the world live in a community), and the Language House, which allows students pursuing language courses to live and practice with other students learning the same language.

    The Mock Trial Team engages in intercollegiate mock trial competition. The team, which first began competing in 1990, has won five national championships (2008, 2000, 1998, 1996, 1992), which ranks the most of any university, and was also the national runner-up in 1992 and 1993.


    On October 14, 2004, the university added 150 acres (61 ha) in an attempt to create the largest research park inside the Washington, D.C., Capital Beltway, formerly known as “M Square,” and now known as the “Discovery District”.

    Many of the faculty members have funding from federal agencies such as the National Science Foundation, the National Institutes of Health, NASA, the Department of Homeland Security, the National Institute of Standards and Technology, and the National Security Agency. These relationships have created numerous research opportunities for the university including:

    Taking the lead in the nationwide research initiative into the transmission and prevention of human and avian influenza.
    Creating a new research center to study the behavioral and social foundations of terrorism with funding from the U.S. Department of Homeland Security
    Launching the joint NASA-University of Maryland Deep Impact spacecraft in early January 2005.

    The University of Maryland Libraries provide access to scholarly information resources required to meet the missions of the university.

    The University of Maryland is an international center for the study of language, hosting the largest community of language scientists in North America, including more than 200 faculty, researchers, and graduate students, who collectively comprise the Maryland Language Science Center. Since 2008 the university has hosted an NSF-IGERT interdisciplinary graduate training program that has served as a catalyst for broader integrative efforts in language science, with 50 participating students and contributions from 50 faculty. The University of Maryland is also home to two key ‘migrator’ centers that connect basic research to critical national needs in education and national security: the Center for Advanced Study of Language (CASL) and the National Foreign Language Center.

    The Center for American Politics and Citizenship provides citizens and policy-makers with research on issues related to the United States’ political institutions, processes, and policies. CAPC is a non-partisan, non-profit research institution within the Department of Government and Politics in the College of Behavioral and Social Sciences.

    The Space Systems Laboratory researches human-robotic interaction for astronautics applications, and includes the only neutral buoyancy facility at a university.

    The Joint Quantum Institute conducts theoretical and experimental research on quantum and atomic physics. The institute was founded in 2006 as a collaboration between the University of Maryland and the National Institute of Standards and Technology (NIST).

    The Center for Technology and Systems Management (CTSM) aims to advance the state of technology and systems analysis for the benefit of people and the environment. The focus is on enhancing safety, efficiency and effectiveness by performing reliability, risk, uncertainty or decision analysis studies.

    The Joint Global Change Research Institute was formed in 2001 by the University of Maryland and the DOE’s Pacific Northwest National Laboratory. The institute focuses on multidisciplinary approaches of climate change research.

    The Center for Advanced Life Cycle Engineering (CALCE) was formed in 1985 at the University of Maryland. CALCE is dedicated to providing a knowledge and resource base to support the development of electronic components, products and systems.

    The National Consortium for the Study of Terrorism and Responses to Terrorism (START) launched in 2005 as one of the Centers of Excellence supported by the Department of Homeland Security in the United States. START is focused on the scientific study of the causes and consequences of terrorism in the United States and around the world.

    The university is tied for 58th in the 2021 U.S. News & World Report rankings of “National Universities” across the United States, and it is ranked tied for 19th nationally among public universities. The Academic Ranking of World Universities ranked Maryland as 43rd in the world in 2015. The 2017–2018 Times Higher Education World University Rankings placed Maryland 69th in the world. The 2016/17 QS World University Rankings ranked Maryland 131st in the world.

    The university was ranked among Peace Corps’ 25 Top Volunteer-Producing Colleges for the tenth consecutive year in 2020. The University of Maryland is ranked among Teach for America’s Top 20 Colleges and Universities, contributing the greatest number of graduating seniors to its 2017 teaching corps. Kiplinger’s Personal Finance ranked the University 10th for in-state students and 16th for out-of-state students in its 2019 Best College Value ranking. Money Magazine ranked the university 1st in the state of Maryland for public colleges in its 2019 Best College for Your Money ranking.

    For the fourth consecutive year in 2015, the university is ranked 1st in the U.S. for the number of Boren Scholarship recipients – with 9 students receiving awards for intensive international language study. The university is ranked as a Top Producing Institution of Fulbright U.S. Students and Scholars for the 2017–2018 academic year by the United States Department of State’s Bureau of Educational and Cultural Affairs.

    In 2017, the University of Maryland was ranked among the top 50 universities in the 2018 Best Global Universities Rankings by U.S. News & World Report based on its high academic research performance and global reputation.

    In 2021, the university was ranked among the top 10 universities in The Princeton Review’s annual survey of the Top Schools for Innovation & Entrepreneurship; this was the sixth consecutive such ranking.

    WMUC-FM (88.1 FM) is the university non-commercial radio station, staffed by UMD students and volunteers. WMUC is a freeform radio station that broadcasts at 10 watts. Its broadcasts can be heard throughout the Washington metropolitan area. Notable WMUC alumni include Connie Chung, Bonnie Bernstein, Peter Rosenberg and Aaron McGruder.

  • richardmitnick 10:52 am on March 9, 2023 Permalink | Reply
    Tags: "CHEOPS mission extended", , , , , Exoplanet research, ,   

    From The University of Geneva [Université de Genève] (CH) And From The University of Bern [Universität Bern] (CH): “CHEOPS mission extended” 

    From The University of Geneva [Université de Genève] (CH)


    From The University of Bern [Universität Bern] (CH)


    Prof. Dr. Willy Benz
    Physics Institute, Space Research and Planetary Sciences (WP), University of Bern
    Phone +41 79 964 92 16
    Email willy.benz@unibe.ch

    Prof. Dr. David Ehrenreich
    Département d’Astronomie and NCCR PlanetS, University of Geneva
    Phone +41 22 379 23 90 / +33 650 396 354
    Email david.ehrenreich@unige.ch

    Prof. Dr. Yann Alibert
    Physics Institute, Space Research and Planetary Sciences (WP) and NCCR PlanetS, University of
    Phone +41 31 684 55 47
    Email yann.alibert@unibe.ch

    After more than three years in orbit, the mission of the CHEOPS space telescope has just been
    extended. Led by From The University of Bern [Universität Bern] (CH) in collaboration with From The University of Geneva [Université de Genève] (CH), CHEOPS is a joint mission of the The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU) and Switzerland. On March 7th, ESA’s Science Programme Committee has confirmed its continued operations to 2026 and
    an indicative extension to 2029, contingent upon ongoing commitments from national contributors and partners. Since its launch in December 2019, the satellite’s extremely precise measurements have contributed to several key discoveries in the field of exoplanets. The extension will make it possible to study these fascinating worlds around other stars in even
    more detail.

    Unlike previous satellites designed to find new exoplanets – planets orbiting stars other than our Sun – by observing tens of thousands of stars simultaneously, CHEOPS has been optimized to observe a single star at a time and it targets stars already known to host exoplanets. The aim of CHEOPS is therefore to go beyond a mere census of exoplanets, and measure some of their key characteristics, in particular their size, with an exquisite precision. This precision is what allows astronomer to infer what these planets are made of: combining the CHEOPS size measurement with the previously
    known planet mass yields the density: dense planets like the Earth are mainly composed of rocks and metals, while planets with low densities like Jupiter are mostly made out of gas. Since these compositions are the result of the planet formation process, getting to know them opens a window to the past history of planetary systems, putting our own Solar System in context.

    Observation of exoplanet properties

    “In this respect, the mission has been extremely successful,” highlights Willy Benz, Professor emeritus
    of astrophysics at the University of Bern and head of the CHEOPS consortium, “the precision of
    CHEOPS has exceeded all expectations and has allowed us to determine properties of several of the
    most interesting exoplanets.”

    For example, by closely observing how the luminosity changes as the planet WASP-103b passes in front of its star, scientists from the CHEOPS team have observed that the planet is deformed into the shape of a rugby ball due to the intense gravity of the nearby star. Such planets are so hot that CHEOPS has also been able to detect them glowing along their orbit around their stars. “The glow detected with CHEOPS for the planet WASP-189b is only a few millionth of the light emitted by the star, and is related to the temperature of the planet atmosphere and its cloud coverage. So it is clear that CHEOPS can do much more than ‘simply’ measuring planet sizes,” explains Prof. David Ehrenreich of the University of Geneva, who is co-chairing the international team of over a hundred of scientists involved in the exploitation of the mission.

    More exciting discoveries with the extended mission

    The primary mission of CHEOPS was planned to last for three and a half years, that is until September 2023. The outstanding quality of the science produced by the mission is attested by the publication of over fifty scientific articles based on CHEOPS data in international journals. The satellite was successfully operated amidst a global pandemic, and its health is excellent with respect to the harsh conditions of space, where it is constantly bombarded by cosmic rays and high-energy radiation.

    All these elements have pushed the CHEOPS team to propose extending the mission beyond 2023. The extension of CHEOPS operations has now been confirmed by the ESA Science Programme Committee until at least 2026, provided ongoing support from national contributors and partners.

    The CHEOPS team members are originating from 40 institutions across Europe: in addition to ESA, 11 countries, including Switzerland in a leading role, have come together to fund and build the telescope between 2012 and 2019. “CHEOPS can continue to count on the strong support of the participating Funding Agencies, including Switzerland, for the extension of the mission, and that the Swiss lead in the CHEOPS mission (including its extended operations) is possible due to the membership of Switzerland in ESA and through its participation in the PRODEX program,” says Oliver Botta, chair of
    the CHEOPS Steering Committee.

    With the newly approved mission extension, the CHEOPS team plans to continue using CHEOPS for what it does best while at the same time trying out new observations. “We have only scratched the surface of the capabilities of CHEOPS, there is much more science that can be done with the satellite and we look forward to exploring it during the extension,” declares Benz. “A very exciting result would be the discovery of the first exomoon,” reveals Ehrenreich. “Many planets in our Solar System have moons, so we expect to find some around exoplanets, and we are currently observing some candidates. It is challenging to detect exomoons though, because they are small, hence their signatures are faint. However, CHEOPS is precise enough to find exomoons as small as the planet Mars, which is twice the size of our Moon. If such moons exist in the systems we observe, we could find them during the extended mission.”

    A unique role in the landscape of space missions

    Another unique characteristic of CHEOPS is its ability to combine forces with other space missions such as the James Webb Space Telescope (JWST), which is a joint mission of NASA and ESA [and CSA]. CHEOPS can refine our knowledge of already known exoplanets to select the best candidates to be observed with JWST to probe the atmospheres of these planets.

    “Thanks to CHEOPS observations, we have been granted valuable JWST time to observe the planets in the TOI-178 system to determine their atmospheric composition, which will help to understand the dynamical history of the system,” specifies Prof. Yann Alibert of the University of Bern. Alibert is coordinating the CHEOPS program dedicated to the follow-up of multiplanetary systems discovered by NASA’s satellite TESS.

    “This is an example of a great synergy between CHEOPS and other missions: TESS originally found 3 planets orbiting the star TOI-178. When CHEOPS looked at this system, it discovered three more planets and revealed an outstanding and fragile orbital harmony, leading us to hypothesize that it has been unperturbed for billions of years,” explains Alibert.

    “Scientists are eager to find out what surprising results CHEOPS will bring next; what is sure now is
    that CHEOPS will continue to make new discoveries for years to come,” concludes Benz.

    See the full article here.

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Bern [Universität Bern] (CH) is a university in the Swiss capital of Bern and was founded in 1834. It is regulated and financed by the Canton of Bern. It is a comprehensive university offering a broad choice of courses and programs in eight faculties and some 150 institutes. With around 17,512 students, Universität Bern is the third biggest University in Switzerland.

    Universität Bern operates at three levels: university, faculties and institutes. Other organizational units include interfaculty and general university units. The university’s highest governing body is the Senate, which is responsible for issuing statutes, rules and regulations. Directly answerable to the Senate is the University Board of Directors, the governing body for university management and coordination. The Board comprises the Rector, the Vice-Rectors and the Administrative Director. The structures and functions of the University Board of Directors and the other organizational units are regulated by the Universities Act. Universität Bern offers about 39 bachelor and 72 master programs, with enrollments of 7,747 and 4,523, respectively. The university also has 2,776 doctoral students. Around 1,561 bachelor, 1,489 master’s degree students and 570 PhD students graduate each year. For some time now, the university has had more female than male students; at the end of 2016, women accounted for 56% of students.

    Today the University of Bern is one of the top 150 universities in the world. In the QS World University Rankings 2019 it ranked 139th. The Shanghai Ranking (ARWU) 2018 ranked the University of Bern in the range 101st–150th in the world. In the Leiden Ranking 2015 it ranked 122nd in the world and 50th in Europe. In the Times Higher Education World University Rankings it ranked 110th in 2018/2019 and 2016/2017 (and 82nd in Clinical, pre-clinical & health 2017).

    The The University of Geneva [Université de Genève] (CH) is a public research university located in Geneva, Switzerland.

    It was founded in 1559 by John Calvin as a theological seminary and law school. It remained focused on theology until the 17th century, when it became a center for Enlightenment scholarship. In 1873, it dropped its religious affiliations and became officially secular. Today, the university is the third largest university in Switzerland by number of students. In 2009, the University of Geneva celebrated the 450th anniversary of its founding. Almost 40% of the students come from foreign countries.

    The university holds and actively pursues teaching, research, and community service as its primary objectives. In 2016, it was ranked 53rd worldwide by the Shanghai Academic Ranking of World Universities, 89th by the QS World University Rankings, and 131st in the TIMES Higher Education World University Ranking.

    UNIGE is a member of the League of European Research Universities (EU) (including academic institutions such as University of Amsterdam [Universiteit van Amsterdam] (NL), University of Cambridge (UK), Ruprecht Karl University of Heidelberg, [Ruprecht-Karls-Universität Heidelberg] (DE), University of Helsinki [ Helsingin yliopisto; Helsingfors universitet] (FI) and University of Milan [Università degli Studi di Milano Statale] (IT)) the Coimbra Group (EU) and the European University Association (EU).

  • richardmitnick 1:43 pm on February 25, 2023 Permalink | Reply
    Tags: , "Two new gas giant exoplanets discovered with TESS", , , At a distance of some 524 light years TOI-5293A is an M3 dwarf about half the size of our sun., , , Exoplanet research, , So far TESS has identified nearly 6200 candidate exoplanets (TESS Objects of Interest or “TO”I) of which 3032 have been confirmed., , The host TOI-3984A is an M4 dwarf about half the size and mass of the sun., The newfound alien worlds-designated TOI-3984A b and TOI-5293A b-have very short orbital periods., The planetary nature of these signals was confirmed by follow-up observations using ground-bases facilities.   

    From The Pennsylvania State University Via “phys.org” : “Two new gas giant exoplanets discovered with TESS” 

    Penn State Bloc

    From The Pennsylvania State University




    The median normalized TESS long-cadence light curve for TOI-3984A. Credit: Cañas et al, 2023.

    Astronomers report the detection of two new gas giant exoplanets using NASA’s Transiting Exoplanet Survey Satellite (TESS).

    The newfound alien worlds-designated TOI-3984A b and TOI-5293A b-have very short orbital periods. The discovery was detailed in a paper published February 15.

    TESS is conducting a survey of about 200,000 of the brightest stars near the sun with the aim of searching for transiting exoplanets. So far, it has identified nearly 6,200 candidate exoplanets (TESS Objects of Interest, or TOI), of which 3,032 have been confirmed so far.

    A group of astronomers led by Caleb I. Cannas of the Pennsylvania State University (PSU) has recently confirmed another two TOI planets monitored by TESS. They report that transit signals have been identified in the light curves of two M-dwarf stars known as TOI-3984A and TOI-5293A—primary stars of two different binary systems. The planetary nature of these signals was confirmed by follow-up observations using ground-bases facilities. Habitable-zone Planet Finder and NEID.

    “We confirm the planetary nature of two gas giants discovered by TESS to transit M dwarfs with stellar companions at wide separations,” the researchers wrote.

    TOI-3984A b has a radius of about 0.71 Jupiter radii and a mass of 0.14 Jupiter masses, which yields a density at a level of 0.49 g/cm3. The planet orbits its parent star every 4.35 days, at a distance of about 0.041 AU from it, and its equilibrium temperature was estimated to be 563 K. Based on its parameters, the astronomers classified TOI-3984A b as a sub-Saturn.

    The host TOI-3984A is an M4 dwarf about half the size and mass of the sun, located approximately 353 light years away from the Earth. The star is estimated to be between 0.7 and 5.1 billion years old and has an effective temperature of 3,476 K. TOI-3984A has a white dwarf companion at a projected separation of 356 AU.

    The exoplanet TOI-5293A b is about the size of Jupiter, however less massive, with a mass of about 0.54 Jupiter masses. Therefore, the planet’s density is approximately 0.56 g/cm3. TOI-5293A b has an orbital period of about 2.93 days and is separated from its host star by approximately 0.034 AU. The equilibrium temperature of this gas giant is estimated to be 675 K, thus the researchers classified it as a hot Jupiter.

    At a distance of some 524 light years TOI-5293A is an M3 dwarf, also about half the size of our sun. The star has an effective temperature of 3,586 K and its age is estimated to be between 0.7 and 5.1 billion years. It has an M-dwarf companion at a projected separation of 579 AU.

    Summing up the results, the authors of the paper underlined that TOI-3984A b and TOI-5293A b are two of the coolest gas giants among the population of known hot Jupiter-sized gas exoplanets orbiting M-dwarf stars. They added that both planets are great targets for further atmospheric characterization studies.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.

    Penn State Campus

    The The Pennsylvania State University is a public state-related land-grant research university with campuses and facilities throughout Pennsylvania. Founded in 1855 as the Farmers’ High School of Pennsylvania, Penn State became the state’s only land-grant university in 1863. Today, Penn State is a major research university which conducts teaching, research, and public service. Its instructional mission includes undergraduate, graduate, professional and continuing education offered through resident instruction and online delivery. In addition to its land-grant designation, it also participates in the sea-grant, space-grant, and sun-grant research consortia; it is one of only four such universities (along with Cornell University, Oregon State University, and University of Hawaiʻi at Mānoa). Its University Park campus, which is the largest and serves as the administrative hub, lies within the Borough of State College and College Township. It has two law schools: Penn State Law, on the school’s University Park campus, and Dickinson Law, in Carlisle. The College of Medicine is in Hershey. Penn State is one university that is geographically distributed throughout Pennsylvania. There are 19 commonwealth campuses and 5 special mission campuses located across the state. The University Park campus has been labeled one of the “Public Ivies,” a publicly funded university considered as providing a quality of education comparable to those of the Ivy League.
    The Pennsylvania State University is a member of The Association of American Universities an organization of American research universities devoted to maintaining a strong system of academic research and education.

    Annual enrollment at the University Park campus totals more than 46,800 graduate and undergraduate students, making it one of the largest universities in the United States. It has the world’s largest dues-paying alumni association. The university offers more than 160 majors among all its campuses.

    Annually, the university hosts the Penn State IFC/Panhellenic Dance Marathon (THON), which is the world’s largest student-run philanthropy. This event is held at the Bryce Jordan Center on the University Park campus. The university’s athletics teams compete in Division I of the NCAA and are collectively known as the Penn State Nittany Lions, competing in the Big Ten Conference for most sports. Penn State students, alumni, faculty and coaches have received a total of 54 Olympic medals.

    Early years

    The school was sponsored by the Pennsylvania State Agricultural Society and founded as a degree-granting institution on February 22, 1855, by Pennsylvania’s state legislature as the Farmers’ High School of Pennsylvania. The use of “college” or “university” was avoided because of local prejudice against such institutions as being impractical in their courses of study. Centre County, Pennsylvania, became the home of the new school when James Irvin of Bellefonte, Pennsylvania, donated 200 acres (0.8 km2) of land – the first of 10,101 acres (41 km^2) the school would eventually acquire. In 1862, the school’s name was changed to the Agricultural College of Pennsylvania, and with the passage of the Morrill Land-Grant Acts, Pennsylvania selected the school in 1863 to be the state’s sole land-grant college. The school’s name changed to the Pennsylvania State College in 1874; enrollment fell to 64 undergraduates the following year as the school tried to balance purely agricultural studies with a more classic education.

    George W. Atherton became president of the school in 1882, and broadened the curriculum. Shortly after he introduced engineering studies, Penn State became one of the ten largest engineering schools in the nation. Atherton also expanded the liberal arts and agriculture programs, for which the school began receiving regular appropriations from the state in 1887. A major road in State College has been named in Atherton’s honor. Additionally, Penn State’s Atherton Hall, a well-furnished and centrally located residence hall, is named not after George Atherton himself, but after his wife, Frances Washburn Atherton. His grave is in front of Schwab Auditorium near Old Main, marked by an engraved marble block in front of his statue.

    Early 20th century

    In the years that followed, Penn State grew significantly, becoming the state’s largest grantor of baccalaureate degrees and reaching an enrollment of 5,000 in 1936. Around that time, a system of commonwealth campuses was started by President Ralph Dorn Hetzel to provide an alternative for Depression-era students who were economically unable to leave home to attend college.

    In 1953, President Milton S. Eisenhower, brother of then-U.S. President Dwight D. Eisenhower, sought and won permission to elevate the school to university status as The Pennsylvania State University. Under his successor Eric A. Walker (1956–1970), the university acquired hundreds of acres of surrounding land, and enrollment nearly tripled. In addition, in 1967, the Penn State Milton S. Hershey Medical Center, a college of medicine and hospital, was established in Hershey with a $50 million gift from the Hershey Trust Company.

    Modern era

    In the 1970s, the university became a state-related institution. As such, it now belongs to the Commonwealth System of Higher Education. In 1975, the lyrics in Penn State’s alma mater song were revised to be gender-neutral in honor of International Women’s Year; the revised lyrics were taken from the posthumously-published autobiography of the writer of the original lyrics, Fred Lewis Pattee, and Professor Patricia Farrell acted as a spokesperson for those who wanted the change.

    In 1989, the Pennsylvania College of Technology in Williamsport joined ranks with the university, and in 2000, so did the Dickinson School of Law. The university is now the largest in Pennsylvania. To offset the lack of funding due to the limited growth in state appropriations to Penn State, the university has concentrated its efforts on philanthropy.


    Penn State is classified among “R1: Doctoral Universities – Very high research activity”. Over 10,000 students are enrolled in the university’s graduate school (including the law and medical schools), and over 70,000 degrees have been awarded since the school was founded in 1922.

    Penn State’s research and development expenditure has been on the rise in recent years. For fiscal year 2013, according to institutional rankings of total research expenditures for science and engineering released by the National Science Foundation , Penn State stood second in the nation, behind only Johns Hopkins University and tied with the Massachusetts Institute of Technology , in the number of fields in which it is ranked in the top ten. Overall, Penn State ranked 17th nationally in total research expenditures across the board. In 12 individual fields, however, the university achieved rankings in the top ten nationally. The fields and sub-fields in which Penn State ranked in the top ten are materials (1st), psychology (2nd), mechanical engineering (3rd), sociology (3rd), electrical engineering (4th), total engineering (5th), aerospace engineering (8th), computer science (8th), agricultural sciences (8th), civil engineering (9th), atmospheric sciences (9th), and earth sciences (9th). Moreover, in eleven of these fields, the university has repeated top-ten status every year since at least 2008. For fiscal year 2011, the National Science Foundation reported that Penn State had spent $794.846 million on R&D and ranked 15th among U.S. universities and colleges in R&D spending.

    For the 2008–2009 fiscal year, Penn State was ranked ninth among U.S. universities by the National Science Foundation, with $753 million in research and development spending for science and engineering. During the 2015–2016 fiscal year, Penn State received $836 million in research expenditures.

    The Applied Research Lab (ARL), located near the University Park campus, has been a research partner with the Department of Defense since 1945 and conducts research primarily in support of the United States Navy. It is the largest component of Penn State’s research efforts statewide, with over 1,000 researchers and other staff members.

    The Materials Research Institute was created to coordinate the highly diverse and growing materials activities across Penn State’s University Park campus. With more than 200 faculty in 15 departments, 4 colleges, and 2 Department of Defense research laboratories, MRI was designed to break down the academic walls that traditionally divide disciplines and enable faculty to collaborate across departmental and even college boundaries. MRI has become a model for this interdisciplinary approach to research, both within and outside the university. Dr. Richard E. Tressler was an international leader in the development of high-temperature materials. He pioneered high-temperature fiber testing and use, advanced instrumentation and test methodologies for thermostructural materials, and design and performance verification of ceramics and composites in high-temperature aerospace, industrial, and energy applications. He was founding director of the Center for Advanced Materials (CAM), which supported many faculty and students from the College of Earth and Mineral Science, the Eberly College of Science, the College of Engineering, the Materials Research Laboratory and the Applied Research Laboratories at Penn State on high-temperature materials. His vision for Interdisciplinary research played a key role in creating the Materials Research Institute, and the establishment of Penn State as an acknowledged leader among major universities in materials education and research.

    The university was one of the founding members of the Worldwide Universities Network (WUN), a partnership that includes 17 research-led universities in the United States, Asia, and Europe. The network provides funding, facilitates collaboration between universities, and coordinates exchanges of faculty members and graduate students among institutions. Former Penn State president Graham Spanier is a former vice-chair of the WUN.

    The Pennsylvania State University Libraries were ranked 14th among research libraries in North America in the 2003–2004 survey released by The Chronicle of Higher Education. The university’s library system began with a 1,500-book library in Old Main. In 2009, its holdings had grown to 5.2 million volumes, in addition to 500,000 maps, five million microforms, and 180,000 films and videos.

    The university’s College of Information Sciences and Technology is the home of CiteSeerX, an open-access repository and search engine for scholarly publications. The university is also the host to the Radiation Science & Engineering Center, which houses the oldest operating university research reactor. Additionally, University Park houses the Graduate Program in Acoustics, the only freestanding acoustics program in the United States. The university also houses the Center for Medieval Studies, a program that was founded to research and study the European Middle Ages, and the Center for the Study of Higher Education (CSHE), one of the first centers established to research postsecondary education.

  • richardmitnick 1:02 pm on February 20, 2023 Permalink | Reply
    Tags: "Journey to the center of terrestrial planets", , , , , , Exoplanet research, The only planetary interiors that we are able to directly explore are within our own Solar System., Two important properties are a planet’s interior structure and its composition., We have been limited to our nearest neighbors-Venus and Mars-with Venus being historically unkind to our technology (“The Venus Curse”).   

    From Astrobites : “Journey to the center of terrestrial planets” 

    From Astrobites

    Keighley Rockcliffe

    Title: Detailed chemical compositions of planet-hosting stars – II. Exploration of the interiors of terrestrial-type exoplanets

    First Author’s Institution: Institute for Particle Physics and Astrophysics, ETH Zürich, Wolfgang-Pauli-Strasse 27, 8093 Zürich, Switzerland

    Authors: H. S. Wang, S. P. Quanz, D. Yong, F. Liu, F. Seidler, L. Acuña, S. J. Mojzsis

    Status: Published in MNRAS [closed access]

    “In 1995, when I was born, there were only a few – hotly contested – exoplanets discovered. Now, there are close to 5000 planets found outside of our Solar System, and many more on the way. The growing population of known exoplanets mixed with the insatiable desire to know if humans are alone in the universe motivates astronomers to measure or estimate the properties of these planets and the environments they exist in.

    Two important properties are a planet’s interior structure and its composition. These can influence many other properties of the planet, such as the presence of an ocean, magnetic field, or volcanoes with the ability to provide gas to the planet’s atmosphere. The only planetary interiors that we are able to directly explore are within our own Solar System. Even then, we have been limited to our nearest neighbors, Venus and Mars, with Venus being historically unkind to our technology (“The Venus Curse”). What, then, are we supposed to do when faced with so many exoplanets to characterize? How can we even begin to speculate at what their surfaces and interiors are like? The authors of today’s paper are taking steps to answer these questions.

    These volatile delights have volatile ends

    The authors base their method on a simple history of the Solar System. When the Earth was formed, it had roughly the same composition of elements as the Sun. Over time, the Earth has lost some of the elements most sensitive to vaporization (“volatiles” – e.g., hydrogen, nitrogen, etc); this is what the authors refer to as the “devolatilisation of Earth”, which is estimated by a factor reducing the Earth’s starting composition to its current composition.

    If we only focus on terrestrial planets that are like Earth – “exo-Earths”, mostly rocky planets within the habitable zone of their Sun-like host star – then the authors suggest that we can assume a similar loss process happens on those planets. The authors hypothesize that if we know how much of a certain element existed when a planet was formed (found by observing and measuring the composition of the planet’s host star), we can use the Earth’s depletion factor for that element to estimate how much of the element currently exists on that planet. The authors limit their analysis to rock-forming volatile elements, such as magnesium, iron, and silicon.

    With the aim of exploring the diversity of exo-Earth interiors today’s authors choose 13 known exoplanet systems with Sun-like host stars which have precise chemical abundance measurements, including measurements for rock-forming volatile elements. Instead of looking at the actual planets around these stars, which vary in size, orbital distance, and potentially also depletion factor, the authors modeled what the interior of an exo-Earth hosted by each star would look like. They plugged the measured amount of rock-forming volatile elements and their depletion factors into the software ExoInt, which output the composition and structure of an exo-Earth core + mantle that best matches the inputs. The output exo-Earth composition and structure was then fed into the software Perple_X to estimate the mineral phases present within the mantle and the temperature, pressure and density of the planet’s interior. Rinse and repeat for all 13 exoplanet systems!

    The main result is that most of the modeled exo-Earths show interiors similar to that of Earth itself. In Figure 2, the shaded parallelograms show the range of molecule-to-molecule ratios that could fit each exo-Earth. Both diagrams show how similar the mantle compositions of all the exo-Earth models are to that of Earth and Mars.Two systems, Kepler-10 and Kepler-37, contain more oxygen than the other systems; oxygen is important in determining how much iron is split between an exo-Earth’s mantle and core. Kepler-10 and Kepler-37 likely have smaller cores because of their higher oxygen content.

    Figure 2: Two ternary diagrams depict a mixture of three chemical components within the mantle: MgO (blue) increasing downwards along the left side of the diagram, SiO2 (red) increasing upwards along the right side, and FeO (green) increasing rightwards along the bottom side. The arrows indicate increasing abundance of the molecule within the mantle.The modeled exo-Earths are split between the two diagrams, which also have the compositions of Earth and Mars marked by blue and red ⨁ symbols, respectively. Not all of the planets are immediately visible because they are on top of one another, especially in the right panel. Image credit: Figure 3 in today’s paper.

    Implications for exoplanet astronomy

    We are currently limited to assuming the depletion/devolatilisation factors of the studied exo-Earths are the same as Earth’s, although the authors show that interior structures may change when these factors are varied. The interior structure models are also limited to only considering a mantle and a one-component core – unlike the two components, inner and outer, that make up Earth’s core. Nevertheless, this work shows that astronomers can use currently available planetary radii and mass measurements along with host star compositions to estimate the interiors of terrestrial planets in the habitable zones of Sun-like stars; combining this with atmospheric observations from telescopes like Hubble and JWST brings us one step closer to finding Earth2.0!”

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”


    Please help promote STEM in your local schools.

    Stem Education Coalition

    What do we do?

    Astrobites is a daily astrophysical literature journal written by graduate students in astronomy. Our goal is to present one interesting paper per day in a brief format that is accessible to undergraduate students in the physical sciences who are interested in active research.
    Why read Astrobites?

    Reading a technical paper from an unfamiliar subfield is intimidating. It may not be obvious how the techniques used by the researchers really work or what role the new research plays in answering the bigger questions motivating that field, not to mention the obscure jargon! For most people, it takes years for scientific papers to become meaningful.

    Our goal is to solve this problem, one paper at a time. In 5 minutes a day reading Astrobites, you should not only learn about one interesting piece of current work, but also get a peek at the broader picture of research in a new area of astronomy.

  • richardmitnick 10:53 am on February 17, 2023 Permalink | Reply
    Tags: "Wolf 1069b - Why System Architecture Matters", , , , , , Exoplanet research, ,   

    From “Centauri Dreams” At follow.it : “Wolf 1069b – Why System Architecture Matters” 

    From “Centauri Dreams”



    Paul Gilster

    Let’s look at a second red dwarf planet in this small series on such, this one being Wolf 1069b. I want to mention it partly because of the prior post on K2-415b, where we had the good fortune to be dealing with a transiting world around an M-dwarf that should be useful in future atmospheric characterization efforts. Wolf 1069b, by contrast, was found by radial velocity methods, and I’m less interested in whether or not it’s in a ‘habitable’ orbit than in the system architecture here, which raises questions.

    This work, recounted in a recent paper in Astronomy & Astrophysics [below], describes a planet that is not just Earth-sized, as is K2-415b, but roughly equivalent to Earth in mass, making a future search for biosignatures interesting once we have the capability of collecting photons directly from the planet. If the planet has an atmosphere, argue the authors of the paper, its surface temperature could reach 13 degrees Celsius, certainly a comfortable temperature for liquid water. A putative atmosphere would also shield the world from harmful radiation from the host star, although Wolf 1069 appears so far to be an unusually quiescent M-dwarf.

    In fact, the lack of distorting surface activity on the star makes possible a high degree of accuracy in the radial velocity measurements here. The data, pulled in by one of the two CARMENES spectrographs, were taken by Diana Kossakowski (MPG Institute for Astronomy (DE), who is lead author of the paper on this work, and colleagues. The CARMENES instruments operate with the 3.5-metre telescope of the Calar Alto Observatory near Almería in southern Spain, and Kossakowski and team have been working the numbers on Wolf 1069 for the past four years.

    The figure shows measurements of the velocities at which the star Wolf 1069 moves towards or away from us by the mean. The measuring points were arranged in such a way that they depict the orbital period of the planet. This shows the tiny but significant variation in motion caused by the planet 1.3 times the mass of Earth orbiting in 15.56 days, and is illustrated by the gray line with the black dots. Credit: © D. Kossakowski et. al. from A&A 2023).

    CARMENES is itself a research consortium (the Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs program). The eleven German and Spanish institutions involved are focusing on Earth-like exoplanets near M-dwarfs, in other words, and I think we can expect the first doubtlessly controversial findings related to biomarkers will emerge on such worlds.

    Wolf 1069b is on a 15.6 day orbit around an M-dwarf about 30 light years away in Cygnus. That distance is, of course, intriguing as we build the catalog for nearby worlds for future study of biomarkers or, one day, probes; the planet counts as the sixth-closest Earth mass world in a habitable zone orbit (the others are Proxima Centauri b, GJ 1061 d, Teegarden’s Star c, and GJ 1002 b and c). Keep in mind that only 1.5 percent of all the more than 5000 exoplanets yet detected have masses below two Earth masses – K2-415b, for all its interest, evidently weighs in at three.

    Tidal lock is likely, though perhaps not a show-stopper for life, especially if the early indications of Wolf 1069’s low levels of activity are born out by future observation, and if an atmosphere is indeed present (without one, the authors estimate, the surface temperature would be 250 K, or -23 °C, as opposed to the + 13 °C mentioned above). So that interesting scenario of daylight (or night) that goes on forever emerges here.

    Simulated surface temperature map of Wolf 1069 b, assuming a modern Earth-like atmosphere. The map is centered at a point that always faces the central star. The temperatures are given in Kelvin (K). 273.15 K corresponds to 0 °C. Liquid water would be possible on the planet’s surface inside the red line. Credit: © Kossakowski et al. (2023) / MPIA.

    But it’s something that MPG Institute for Astronomy scientist Remo Burn said that catches my eye:

    “Our computer simulations show that about 5% of all evolving planetary systems around low-mass stars, such as Wolf 1069, end up with a single detectable planet. The simulations also reveal a stage of violent encounters with planetary embryos during the construction of the planetary system, leading to occasional catastrophic impacts,”

    That’s a noteworthy thought, for such impacts could generate a planetary core that remains liquid today, resulting in a global magnetic field that would offer further shielding effects from stellar activity. The question would be whether Wolf 1069b really is alone, and on this the results are simply not in. What the researchers have been able to do is to exclude additional planets of Earth mass or more and orbital periods of less than 10 days. What they cannot do yet is rule out planets on wider orbits.

    If alone around its star, Wolf 1069b is the only one of the six Earth-mass planets in habitable zones nearest to Earth that is found without an inner planet keeping it company. Note that the mass of Wolf 1069 is 0.167±0.011 solar masses. And now let’s turn to the paper:

    “This notion is supported by the works of Burn et al. (2021), Mulders et al. (2021), and Schlecker et al. (2021), where we expect a lower planet occurrence rate for stars with M* < 0.2 M⊙ than for stars with 0.2 M⊙ < M* < 0.5 M⊙ for both the pebble and core accretion scenarios."

    The authors run this out on a rather lengthy speculative thread:

    "Granted, these are theoretical predictions as more observation-based evidence is required to confirm this, and Wolf 1069b could still be accompanied by closer-in and outer planets. Nevertheless, the concept that only one planet survives is predicted by formation models if there were at least one giant impact at the late stage. This would enhance the chance of having a massive moon similar to the Earth and might also stir up the interior of the planet to prevent stratification and sustain a magnetic field (e.g., Jacobson et al. 2017). As remote as this appears, the search for exo-moons is no longer so far-fetched in recent times (e.g., Martínez-Rodríguez et al. 2019; Dobos et al. 2022).”

    In the absence of data on these matters, speculation is welcome, but I can only imagine that when we get the right instrumentation online to make direct observations of planets like Wolf 1069b, we’re going to find more than our share of surprises. Whether or not an exo-moon hinting at an impact hinting at a magnetic field is one of them remains to be seen. A lot of ‘ifs’ creep into discussions of ‘habitable’ worlds. Would a tidally locked red dwarf planet look something like the speculation we see below?

    Artist’s conception of a rocky Earth-mass exoplanet like Wolf 1069 b orbiting a red dwarf star. If the planet had retained its atmosphere, chances are high that it would feature liquid water and habitable conditions over a wide area of its dayside. Credit: © Daniel Rutter/ NASA/Ames Research Center.

    Astronomy & Astrophysics

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


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    Tracking Research into Deep Space Exploration
    Alpha Centauri and other nearby stars seem impossible destinations not just for manned missions but even for robotic probes like Cassini or Galileo. Nonetheless, serious work on propulsion, communications, long-life electronics and spacecraft autonomy continues at NASA, ESA and many other venues, some in academia, some in private industry. The goal of reaching the stars is a distant one and the work remains low-key, but fascinating ideas continue to emerge. This site will track current research. I’ll also throw in the occasional musing about the literary and cultural implications of interstellar flight.
    Centauris Alpha Beta Proxima, 27 February 2012. Skatebiker.

    National Aeronautics and Space Administration Galileo Spacecraft 1989-2003.
    Ultimately, the challenge may be as much philosophical as technological: to reassert the value of the long haul in a time of jittery short-term thinking.

  • richardmitnick 7:23 am on February 3, 2023 Permalink | Reply
    Tags: " 'Hot Jupiter' Is in a Possible Death Spiral", , , , , , , Exoplanet research, , ,   

    From Princeton University And From The Harvard-Smithsonian Center for Astrophysics Via “Eos” : ” ‘Hot Jupiter’ Is in a Possible Death Spiral” 

    Princeton University

    From Princeton University


    From The Harvard-Smithsonian Center for Astrophysics


    Eos news bloc




    Damond Benningfield

    Kepler-1658b is spiraling closer to its star in this artist’s rendering. Credit: Gabriel Perez Diaz/Instituto de Astrofísica de Canarias.

    A distant planet is in a death spiral and is poised to be engulfed by its parent star.

    Kepler-1658b is the first inspiraling planet discovered around an “evolved” star—one that has moved out of its prime life. The star—Kepler-1658—is about 1.5 times the mass of our Sun and has expanded to almost 3 times the Sun’s diameter in its late stages of life, earning it the designation of subgiant.

    Should Kepler-1658b maintain its current path, it will meet its fate in about 2.5 million years.

    As the complicated discovery of the planet and its star has shown, however, nothing is certain. “It’s a very confounding system,” said Ashley Chontos, a postdoctoral fellow at Princeton University and a member of the team that discovered the planet’s shrinking orbit.

    Kepler-1658b was the first exoplanet discovered by the Kepler space telescope, which found thousands of bodies over its lifetime using the transit technique. The telescope measured tiny dips in a star’s brightness when a planet crossed in front of it.

    Kepler stares into a galaxy filled with its exoplanet discoveries in this illustration commissioned for the space telescope’s retirement. Credit: NASA.

    Early in its mission, Kepler recorded such dips from Kepler-1658. However, astronomers had initially cataloged the star as belonging to the main sequence—stars like the Sun that are still burning the hydrogen in their cores. Researchers expected the star to be much smaller than it is, so the initial transit signals “didn’t make sense,” said Shreyas Vissapragada, a postdoctoral researcher at the Harvard-Smithsonian Center for Astrophysics and lead author of the new study [The Astrophysical Journal Letters (below)]. The transit indicated a planet roughly the size of Neptune, our solar system’s third-largest planet. However, the system also produced a secondary eclipse as the planet passed behind the star. At Kepler 1658’s distance, a Neptune-sized planet wouldn’t be bright enough to see, so there would be no evidence of the secondary eclipse.

    Kepler-1658b was discarded as a false positive and forgotten about.

    That is, until Chontos began looking at vibrations on the surfaces of stars in the Kepler catalog. Because the telescope kept a constant eye on the stars in its field of view, recording brightness levels every half hour or less, it detected “jiggles” caused by sound waves reverberating through the stars. Piecing together the vibrations—a technique known as asteroseismology—revealed details about the stars’ interiors.

    In the case of Kepler-1658, they showed that the star was much farther along in life than expected and hence about 3 times bigger. That meant the transiting planet was 3 times larger as well, making it big enough and bright enough to contribute to the system’s overall brightness when it wasn’t eclipsed by the star. “Suddenly, a close-in hot Jupiter made sense,” Chontos said. “That discovery [The Astronomical Journal (below)] was completely accidental.”

    A hot Jupiter is a massive planet comparable to Jupiter—the giant of our own solar system—that orbits so close to its star that it is extremely hot. In this case, Kepler-1658b is about the size of Jupiter, but with almost 6 times its mass. “Even the combined masses of all the planets in [our] solar system don’t add up to that,” Chontos said. The planet orbits its star once every 3.85 Earth days, compared with an 88-day period for Mercury, the Sun’s closest planet.

    Changing a Planetary Clock

    Kepler observed the system for about 4 years, so it obtained a pretty good, but not perfect, measurement of the orbital period. It appeared to show that Kepler-1658b followed a steady path around the star.

    At the same time Chontos was studying the system’s vibrations, though, Vissapragada was conducting his own observations. One night, in fact, he and Chontos bumped into each other during runs at the 200-inch Hale Telescope at Palomar Observatory, where both were looking at the system.

    Vissapragada obtained data from two Hale sessions plus three monthlong sets of observations by the Transiting Exoplanet Survey Satellite (TESS), a space telescope designed to discover and study exoplanets.

    When combined with the earlier Kepler data, the data provided a 13-year baseline of observations.

    “They showed that the clock had changed—the transits were happening measurably earlier than they were predicted to occur,” Vissapragada said. Kepler-1658b’s orbital period was decreasing by 131 milliseconds per year (plus or minus about 20 milliseconds), suggesting the planet will spiral into the star in about 2.5 million years.

    The shrinking orbit is probably the result of tidal effects. “We think we know the total energy in the system,” Chontos said. “The planet is depositing energy in the star, causing it to rotate faster and the planet’s orbit to shrink.” A small amount of the system’s total energy could be dissipated in the planet as well, explaining some minor oddities in its orbit, Vissapragada added.

    Ruling Out the Alternatives

    An inspiral isn’t the only possible explanation for the apparent change in orbital period, however. The timing could appear to change if the system were moving toward us, for example. By measuring the system’s radial velocity—its motion toward or away from us—the team ruled out that possibility.

    It also ruled out the possibility that we see only part of the orbit’s precession period—a “wobble” in the orbit. “We think we’ve ruled out all other probable causes,” said Vissapragada.

    “The evidence for inspiraling planets is plausible, and this paper presents good arguments for this being the case for this planet,” said Girish Duvvuri, a graduate research assistant at the University of Colorado-Boulder who has studied the demise of exoplanets but was not involved in this project. “While I can’t say they’ve exhausted all alternative hypotheses, they covered everything I can think of.”

    Even so, no one can say the fate of Kepler-1658b is sealed. The process of orbital evolution for planets around evolving stars is poorly understood, so several outcomes are possible.

    “The whole dissipation process is very complicated,” Chontos said. “It involves the obliquity, eccentricity, distance—all these different aspects of the orbit that can change over time. While it’s going inward now, there’s nothing to say that the orbit won’t circularize and its migration will stop—just halt. At some point, the planet might even migrate outward. But right now, that’s all just speculation.”

    The astronomers hope to narrow down the possibilities with additional observations of the system by TESS and other ground- and space-based telescopes. And they said that finding similar systems will help as well.

    “We need to look at more of these systems to pin down exactly how that evolution works,” Vissapragada said. “TESS should give us a lot more examples over the next decade, so we’ll have a fairly large sample to see if this mechanism is common.”

    The Astrophysical Journal Letters 2022
    The Astronomical Journal 2019
    See the science papers for instructive material with images.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

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    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.

    The Harvard-Smithsonian Center for Astrophysics combines the resources and research facilities of the Harvard College Observatory and the Smithsonian Astrophysical Observatory under a single director to pursue studies of those basic physical processes that determine the nature and evolution of the universe. The Smithsonian Astrophysical Observatory is a bureau of the Smithsonian Institution, founded in 1890. The Harvard College Observatory, founded in 1839, is a research institution of the Faculty of Arts and Sciences, Harvard University, and provides facilities and substantial other support for teaching activities of the Department of Astronomy.

    Founded in 1973 and headquartered in Cambridge, Massachusetts, the CfA leads a broad program of research in astronomy, astrophysics, Earth and space sciences, as well as science education. The CfA either leads or participates in the development and operations of more than fifteen ground- and space-based astronomical research observatories across the electromagnetic spectrum, including the forthcoming Giant Magellan Telescope(CL) and the Chandra X-ray Observatory, one of NASA’s Great Observatories.

    GMT Giant Magellan Telescope(CL) 21 meters, to be at the Carnegie Institution for Science’s NSF NOIRLab NOAO Las Campanas Observatory(CL) some 115 km (71 mi) north-northeast of La Serena, Chile, over 2,500 m (8,200 ft) high.

    National Aeronautics and Space Administration Chandra X-ray telescope.

    Hosting more than 850 scientists, engineers, and support staff, the CfA is among the largest astronomical research institutes in the world. Its projects have included Nobel Prize-winning advances in cosmology and high energy astrophysics, the discovery of many exoplanets, and the first image of a black hole. The CfA also serves a major role in the global astrophysics research community: the CfA’s Astrophysics Data System, for example, has been universally adopted as the world’s online database of astronomy and physics papers. Known for most of its history as the “Harvard-Smithsonian Center for Astrophysics”, the CfA rebranded in 2018 to its current name in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. The CfA’s current Director (since 2004) is Charles R. Alcock, who succeeds Irwin I. Shapiro (Director from 1982 to 2004) and George B. Field (Director from 1973 to 1982).

    The Center for Astrophysics | Harvard & Smithsonian is not formally an independent legal organization, but rather an institutional entity operated under a Memorandum of Understanding between Harvard University and the Smithsonian Institution. This collaboration was formalized on July 1, 1973, with the goal of coordinating the related research activities of the Harvard College Observatory (HCO) and the Smithsonian Astrophysical Observatory (SAO) under the leadership of a single Director, and housed within the same complex of buildings on the Harvard campus in Cambridge, Massachusetts. The CfA’s history is therefore also that of the two fully independent organizations that comprise it. With a combined lifetime of more than 300 years, HCO and SAO have been host to major milestones in astronomical history that predate the CfA’s founding.

    History of the Smithsonian Astrophysical Observatory (SAO)

    Samuel Pierpont Langley, the third Secretary of the Smithsonian, founded the Smithsonian Astrophysical Observatory on the south yard of the Smithsonian Castle (on the U.S. National Mall) on March 1,1890. The Astrophysical Observatory’s initial, primary purpose was to “record the amount and character of the Sun’s heat”. Charles Greeley Abbot was named SAO’s first director, and the observatory operated solar telescopes to take daily measurements of the Sun’s intensity in different regions of the optical electromagnetic spectrum. In doing so, the observatory enabled Abbot to make critical refinements to the Solar constant, as well as to serendipitously discover Solar variability. It is likely that SAO’s early history as a solar observatory was part of the inspiration behind the Smithsonian’s “sunburst” logo, designed in 1965 by Crimilda Pontes.

    In 1955, the scientific headquarters of SAO moved from Washington, D.C. to Cambridge, Massachusetts to affiliate with the Harvard College Observatory (HCO). Fred Lawrence Whipple, then the chairman of the Harvard Astronomy Department, was named the new director of SAO. The collaborative relationship between SAO and HCO therefore predates the official creation of the CfA by 18 years. SAO’s move to Harvard’s campus also resulted in a rapid expansion of its research program. Following the launch of Sputnik (the world’s first human-made satellite) in 1957, SAO accepted a national challenge to create a worldwide satellite-tracking network, collaborating with the United States Air Force on Project Space Track.

    With the creation of National Aeronautics and Space Administration the following year and throughout the space race, SAO led major efforts in the development of orbiting observatories and large ground-based telescopes, laboratory and theoretical astrophysics, as well as the application of computers to astrophysical problems.

    History of Harvard College Observatory (HCO)

    Partly in response to renewed public interest in astronomy following the 1835 return of Halley’s Comet, the Harvard College Observatory was founded in 1839, when the Harvard Corporation appointed William Cranch Bond as an “Astronomical Observer to the University”. For its first four years of operation, the observatory was situated at the Dana-Palmer House (where Bond also resided) near Harvard Yard, and consisted of little more than three small telescopes and an astronomical clock. In his 1840 book recounting the history of the college, then Harvard President Josiah Quincy III noted that “…there is wanted a reflecting telescope equatorially mounted…”. This telescope, the 15-inch “Great Refractor”, opened seven years later (in 1847) at the top of Observatory Hill in Cambridge (where it still exists today, housed in the oldest of the CfA’s complex of buildings). The telescope was the largest in the United States from 1847 until 1867. William Bond and pioneer photographer John Adams Whipple used the Great Refractor to produce the first clear Daguerrotypes of the Moon (winning them an award at the 1851 Great Exhibition in London). Bond and his son, George Phillips Bond (the second Director of HCO), used it to discover Saturn’s 8th moon, Hyperion (which was also independently discovered by William Lassell).

    Under the directorship of Edward Charles Pickering from 1877 to 1919, the observatory became the world’s major producer of stellar spectra and magnitudes, established an observing station in Peru, and applied mass-production methods to the analysis of data. It was during this time that HCO became host to a series of major discoveries in astronomical history, powered by the Observatory’s so-called “Computers” (women hired by Pickering as skilled workers to process astronomical data). These “Computers” included Williamina Fleming; Annie Jump Cannon; Henrietta Swan Leavitt; Florence Cushman; and Antonia Maury, all widely recognized today as major figures in scientific history. Henrietta Swan Leavitt, for example, discovered the so-called period-luminosity relation for Classical Cepheid variable stars, establishing the first major “standard candle” with which to measure the distance to galaxies. Now called “Leavitt’s Law”, the discovery is regarded as one of the most foundational and important in the history of astronomy; astronomers like Edwin Hubble, for example, would later use Leavitt’s Law to establish that the Universe is expanding, the primary piece of evidence for the Big Bang model.

    Upon Pickering’s retirement in 1921, the Directorship of HCO fell to Harlow Shapley (a major participant in the so-called “Great Debate” of 1920). This era of the observatory was made famous by the work of Cecelia Payne-Gaposchkin, who became the first woman to earn a Ph.D. in astronomy from Radcliffe College (a short walk from the Observatory). Payne-Gapochkin’s 1925 thesis proposed that stars were composed primarily of hydrogen and helium, an idea thought ridiculous at the time. Between Shapley’s tenure and the formation of the CfA, the observatory was directed by Donald H. Menzel and then Leo Goldberg, both of whom maintained widely recognized programs in solar and stellar astrophysics. Menzel played a major role in encouraging the Smithsonian Astrophysical Observatory to move to Cambridge and collaborate more closely with HCO.

    Joint history as the Center for Astrophysics (CfA)

    The collaborative foundation for what would ultimately give rise to the Center for Astrophysics began with SAO’s move to Cambridge in 1955. Fred Whipple, who was already chair of the Harvard Astronomy Department (housed within HCO since 1931), was named SAO’s new director at the start of this new era; an early test of the model for a unified Directorship across HCO and SAO. The following 18 years would see the two independent entities merge ever closer together, operating effectively (but informally) as one large research center.

    This joint relationship was formalized as the new Harvard–Smithsonian Center for Astrophysics on July 1, 1973. George B. Field, then affiliated with University of California- Berkeley, was appointed as its first Director. That same year, a new astronomical journal, the CfA Preprint Series was created, and a CfA/SAO instrument flying aboard Skylab discovered coronal holes on the Sun. The founding of the CfA also coincided with the birth of X-ray astronomy as a new, major field that was largely dominated by CfA scientists in its early years. Riccardo Giacconi, regarded as the “father of X-ray astronomy”, founded the High Energy Astrophysics Division within the new CfA by moving most of his research group (then at American Sciences and Engineering) to SAO in 1973. That group would later go on to launch the Einstein Observatory (the first imaging X-ray telescope) in 1976, and ultimately lead the proposals and development of what would become the Chandra X-ray Observatory. Chandra, the second of NASA’s Great Observatories and still the most powerful X-ray telescope in history, continues operations today as part of the CfA’s Chandra X-ray Center. Giacconi would later win the 2002 Nobel Prize in Physics for his foundational work in X-ray astronomy.

    Shortly after the launch of the Einstein Observatory, the CfA’s Steven Weinberg won the 1979 Nobel Prize in Physics for his work on electroweak unification. The following decade saw the start of the landmark CfA Redshift Survey (the first attempt to map the large scale structure of the Universe), as well as the release of the Field Report, a highly influential Astronomy & Astrophysics Decadal Survey chaired by the outgoing CfA Director George Field. He would be replaced in 1982 by Irwin Shapiro, who during his tenure as Director (1982 to 2004) oversaw the expansion of the CfA’s observing facilities around the world.

    Harvard Smithsonian Center for Astrophysics Fred Lawrence Whipple Observatory located near Amado, Arizona on the slopes of Mount Hopkins, Altitude 2,606 m (8,550 ft)

    European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne] [Europäische Weltraumorganization] (EU)/National Aeronautics and Space Administration SOHO satellite. Launched in 1995.

    National Aeronautics Space Agency NASA Kepler Space Telescope

    CfA-led discoveries throughout this period include canonical work on Supernova 1987A, the “CfA2 Great Wall” (then the largest known coherent structure in the Universe), the best-yet evidence for supermassive black holes, and the first convincing evidence for an extrasolar planet.

    The 1990s also saw the CfA unwittingly play a major role in the history of computer science and the internet: in 1990, SAO developed SAOImage, one of the world’s first X11-based applications made publicly available (its successor, DS9, remains the most widely used astronomical FITS image viewer worldwide). During this time, scientists at the CfA also began work on what would become the Astrophysics Data System (ADS), one of the world’s first online databases of research papers. By 1993, the ADS was running the first routine transatlantic queries between databases, a foundational aspect of the internet today.

    The CfA Today

    Research at the CfA

    Charles Alcock, known for a number of major works related to massive compact halo objects, was named the third director of the CfA in 2004. Today Alcock overseas one of the largest and most productive astronomical institutes in the world, with more than 850 staff and an annual budget in excess of $100M. The Harvard Department of Astronomy, housed within the CfA, maintains a continual complement of approximately 60 Ph.D. students, more than 100 postdoctoral researchers, and roughly 25 undergraduate majors in astronomy and astrophysics from Harvard College. SAO, meanwhile, hosts a long-running and highly rated REU Summer Intern program as well as many visiting graduate students. The CfA estimates that roughly 10% of the professional astrophysics community in the United States spent at least a portion of their career or education there.

    The CfA is either a lead or major partner in the operations of the Fred Lawrence Whipple Observatory, the Submillimeter Array, MMT Observatory, the South Pole Telescope, VERITAS, and a number of other smaller ground-based telescopes. The CfA’s 2019-2024 Strategic Plan includes the construction of the Giant Magellan Telescope as a driving priority for the Center.

    CFA Harvard Smithsonian Submillimeter Array on Mauna Kea, Hawai’i, Altitude 4,205 m (13,796 ft).

    South Pole Telescope SPTPOL. The SPT collaboration is made up of over a dozen (mostly North American) institutions, including The University of Chicago ; The University of California-Berkeley ; Case Western Reserve University; Harvard/Smithsonian Astrophysical Observatory; The University of Colorado- Boulder; McGill (CA) University, The University of Illinois, Urbana-Champaign; The University of California- Davis; Ludwig Maximilians Universität München(DE); DOE’s Argonne National Laboratory; and The National Institute for Standards and Technology.

    Along with the Chandra X-ray Observatory, the CfA plays a central role in a number of space-based observing facilities, including the recently launched Parker Solar Probe, Kepler Space Telescope, the Solar Dynamics Observatory (SDO), and HINODE. The CfA, via the Smithsonian Astrophysical Observatory, recently played a major role in the Lynx X-ray Observatory, a NASA-Funded Large Mission Concept Study commissioned as part of the 2020 Decadal Survey on Astronomy and Astrophysics (“Astro2020”). If launched, Lynx would be the most powerful X-ray observatory constructed to date, enabling order-of-magnitude advances in capability over Chandra.

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker. The Johns Hopkins University Applied Physics Lab.

    National Aeronautics and Space Administration Solar Dynamics Observatory.

    Japan Aerospace Exploration Agency (JAXA) (国立研究開発法人宇宙航空研究開発機構] (JP)/National Aeronautics and Space Administration HINODE spacecraft.

    SAO is one of the 13 stakeholder institutes for the Event Horizon Telescope Board, and the CfA hosts its Array Operations Center. In 2019, the project revealed the first direct image of a black hole.

    Messier 87*, The first image of the event horizon of a black hole. This is the supermassive black hole at the center of the galaxy Messier 87. Image via The Event Horizon Telescope Collaboration released on 10 April 2019 via National Science Foundation.

    The result is widely regarded as a triumph not only of observational radio astronomy, but of its intersection with theoretical astrophysics. Union of the observational and theoretical subfields of astrophysics has been a major focus of the CfA since its founding.

    In 2018, the CfA rebranded, changing its official name to the “Center for Astrophysics | Harvard & Smithsonian” in an effort to reflect its unique status as a joint collaboration between Harvard University and the Smithsonian Institution. Today, the CfA receives roughly 70% of its funding from NASA, 22% from Smithsonian federal funds, and 4% from the National Science Foundation. The remaining 4% comes from contributors including the United States Department of Energy, the Annenberg Foundation, as well as other gifts and endowments.

    About Princeton: Overview

    Princeton University is a private Ivy League research university in Princeton, New Jersey (US). Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. The institution moved to Newark in 1747, then to the current site nine years later. It was renamed Princeton University in 1896.

    Princeton provides undergraduate and graduate instruction in the humanities, social sciences, natural sciences, and engineering. It offers professional degrees through the Princeton School of Public and International Affairs, the School of Engineering and Applied Science, the School of Architecture and the Bendheim Center for Finance. The university also manages the DOE’s Princeton Plasma Physics Laboratory. Princeton has the largest endowment per student in the United States.

    As of October 2020, 69 Nobel laureates, 15 Fields Medalists and 14 Turing Award laureates have been affiliated with Princeton University as alumni, faculty members or researchers. In addition, Princeton has been associated with 21 National Medal of Science winners, 5 Abel Prize winners, 5 National Humanities Medal recipients, 215 Rhodes Scholars, 139 Gates Cambridge Scholars and 137 Marshall Scholars. Two U.S. Presidents, twelve U.S. Supreme Court Justices (three of whom currently serve on the court) and numerous living billionaires and foreign heads of state are all counted among Princeton’s alumni body. Princeton has also graduated many prominent members of the U.S. Congress and the U.S. Cabinet, including eight Secretaries of State, three Secretaries of Defense and the current Chairman of the Joint Chiefs of Staff.

    Princeton University, founded as the College of New Jersey, was considered the successor of the “Log College” founded by the Reverend William Tennent at Neshaminy, PA in about 1726. New Light Presbyterians founded the College of New Jersey in 1746 in Elizabeth, New Jersey. Its purpose was to train ministers. The college was the educational and religious capital of Scottish Presbyterian America. Unlike Harvard University , which was originally “intensely English” with graduates taking the side of the crown during the American Revolution, Princeton was founded to meet the religious needs of the period and many of its graduates took the American side in the war. In 1754, trustees of the College of New Jersey suggested that, in recognition of Governor Jonathan Belcher’s interest, Princeton should be named as Belcher College. Belcher replied: “What a name that would be!” In 1756, the college moved its campus to Princeton, New Jersey. Its home in Princeton was Nassau Hall, named for the royal House of Orange-Nassau of William III of England.

    Following the untimely deaths of Princeton’s first five presidents, John Witherspoon became president in 1768 and remained in that post until his death in 1794. During his presidency, Witherspoon shifted the college’s focus from training ministers to preparing a new generation for secular leadership in the new American nation. To this end, he tightened academic standards and solicited investment in the college. Witherspoon’s presidency constituted a long period of stability for the college, interrupted by the American Revolution and particularly the Battle of Princeton, during which British soldiers briefly occupied Nassau Hall; American forces, led by George Washington, fired cannon on the building to rout them from it.

    In 1812, the eighth president of the College of New Jersey, Ashbel Green (1812–23), helped establish the Princeton Theological Seminary next door. The plan to extend the theological curriculum met with “enthusiastic approval on the part of the authorities at the College of New Jersey.” Today, Princeton University and Princeton Theological Seminary maintain separate institutions with ties that include services such as cross-registration and mutual library access.

    Before the construction of Stanhope Hall in 1803, Nassau Hall was the college’s sole building. The cornerstone of the building was laid on September 17, 1754. During the summer of 1783, the Continental Congress met in Nassau Hall, making Princeton the country’s capital for four months. Over the centuries and through two redesigns following major fires (1802 and 1855), Nassau Hall’s role shifted from an all-purpose building, comprising office, dormitory, library, and classroom space; to classroom space exclusively; to its present role as the administrative center of the University. The class of 1879 donated twin lion sculptures that flanked the entrance until 1911, when that same class replaced them with tigers. Nassau Hall’s bell rang after the hall’s construction; however, the fire of 1802 melted it. The bell was then recast and melted again in the fire of 1855.

    James McCosh became the college’s president in 1868 and lifted the institution out of a low period that had been brought about by the American Civil War. During his two decades of service, he overhauled the curriculum, oversaw an expansion of inquiry into the sciences, and supervised the addition of a number of buildings in the High Victorian Gothic style to the campus. McCosh Hall is named in his honor.

    In 1879, the first thesis for a Doctor of Philosophy (Ph.D.) was submitted by James F. Williamson, Class of 1877.

    In 1896, the college officially changed its name from the College of New Jersey to Princeton University to honor the town in which it resides. During this year, the college also underwent large expansion and officially became a university. In 1900, the Graduate School was established.

    In 1902, Woodrow Wilson, graduate of the Class of 1879, was elected the 13th president of the university. Under Wilson, Princeton introduced the preceptorial system in 1905, a then-unique concept in the United States that augmented the standard lecture method of teaching with a more personal form in which small groups of students, or precepts, could interact with a single instructor, or preceptor, in their field of interest.

    In 1906, the reservoir Carnegie Lake was created by Andrew Carnegie. A collection of historical photographs of the building of the lake is housed at the Seeley G. Mudd Manuscript Library on Princeton’s campus. On October 2, 1913, the Princeton University Graduate College was dedicated. In 1919 the School of Architecture was established. In 1933, Albert Einstein became a lifetime member of the Institute for Advanced Study with an office on the Princeton campus. While always independent of the university, the Institute for Advanced Study occupied offices in Jones Hall for 6 years, from its opening in 1933, until its own campus was finished and opened in 1939.


    In 1969, Princeton University first admitted women as undergraduates. In 1887, the university actually maintained and staffed a sister college, Evelyn College for Women, in the town of Princeton on Evelyn and Nassau streets. It was closed after roughly a decade of operation. After abortive discussions with Sarah Lawrence College to relocate the women’s college to Princeton and merge it with the University in 1967, the administration decided to admit women and turned to the issue of transforming the school’s operations and facilities into a female-friendly campus. The administration had barely finished these plans in April 1969 when the admissions office began mailing out its acceptance letters. Its five-year coeducation plan provided $7.8 million for the development of new facilities that would eventually house and educate 650 women students at Princeton by 1974. Ultimately, 148 women, consisting of 100 freshmen and transfer students of other years, entered Princeton on September 6, 1969 amidst much media attention. Princeton enrolled its first female graduate student, Sabra Follett Meservey, as a PhD candidate in Turkish history in 1961. A handful of undergraduate women had studied at Princeton from 1963 on, spending their junior year there to study “critical languages” in which Princeton’s offerings surpassed those of their home institutions. They were considered regular students for their year on campus, but were not candidates for a Princeton degree.

    As a result of a 1979 lawsuit by Sally Frank, Princeton’s eating clubs were required to go coeducational in 1991, after Tiger Inn’s appeal to the U.S. Supreme Court was denied. In 1987, the university changed the gendered lyrics of “Old Nassau” to reflect the school’s co-educational student body. From 2009 to 2011, Princeton professor Nannerl O. Keohane chaired a committee on undergraduate women’s leadership at the university, appointed by President Shirley M. Tilghman.

    The main campus sits on about 500 acres (2.0 km^2) in Princeton. In 2011, the main campus was named by Travel+Leisure as one of the most beautiful in the United States. The James Forrestal Campus is split between nearby Plainsboro and South Brunswick. The University also owns some property in West Windsor Township. The campuses are situated about one hour from both New York City and Philadelphia.

    The first building on campus was Nassau Hall, completed in 1756 and situated on the northern edge of campus facing Nassau Street. The campus expanded steadily around Nassau Hall during the early and middle 19th century. The McCosh presidency (1868–88) saw the construction of a number of buildings in the High Victorian Gothic and Romanesque Revival styles; many of them are now gone, leaving the remaining few to appear out of place. At the end of the 19th century much of Princeton’s architecture was designed by the Cope and Stewardson firm (same architects who designed a large part of Washington University in St Louis and University of Pennsylvania) resulting in the Collegiate Gothic style for which it is known today. Implemented initially by William Appleton Potter and later enforced by the University’s supervising architect, Ralph Adams Cram, the Collegiate Gothic style remained the standard for all new building on the Princeton campus through 1960. A flurry of construction in the 1960s produced a number of new buildings on the south side of the main campus, many of which have been poorly received. Several prominent architects have contributed some more recent additions, including Frank Gehry (Lewis Library), I. M. Pei (Spelman Halls), Demetri Porphyrios (Whitman College, a Collegiate Gothic project), Robert Venturi and Denise Scott Brown (Frist Campus Center, among several others), and Rafael Viñoly (Carl Icahn Laboratory).

    A group of 20th-century sculptures scattered throughout the campus forms the Putnam Collection of Sculpture. It includes works by Alexander Calder (Five Disks: One Empty), Jacob Epstein (Albert Einstein), Henry Moore (Oval with Points), Isamu Noguchi (White Sun), and Pablo Picasso (Head of a Woman). Richard Serra’s The Hedgehog and The Fox is located between Peyton and Fine halls next to Princeton Stadium and the Lewis Library.

    At the southern edge of the campus is Carnegie Lake, an artificial lake named for Andrew Carnegie. Carnegie financed the lake’s construction in 1906 at the behest of a friend who was a Princeton alumnus. Carnegie hoped the opportunity to take up rowing would inspire Princeton students to forsake football, which he considered “not gentlemanly.” The Shea Rowing Center on the lake’s shore continues to serve as the headquarters for Princeton rowing.

    Cannon Green

    Buried in the ground at the center of the lawn south of Nassau Hall is the “Big Cannon,” which was left in Princeton by British troops as they fled following the Battle of Princeton. It remained in Princeton until the War of 1812, when it was taken to New Brunswick. In 1836 the cannon was returned to Princeton and placed at the eastern end of town. It was removed to the campus under cover of night by Princeton students in 1838 and buried in its current location in 1840.

    A second “Little Cannon” is buried in the lawn in front of nearby Whig Hall. This cannon, which may also have been captured in the Battle of Princeton, was stolen by students of Rutgers University in 1875. The theft ignited the Rutgers-Princeton Cannon War. A compromise between the presidents of Princeton and Rutgers ended the war and forced the return of the Little Cannon to Princeton. The protruding cannons are occasionally painted scarlet by Rutgers students who continue the traditional dispute.

    In years when the Princeton football team beats the teams of both Harvard University and Yale University in the same season, Princeton celebrates with a bonfire on Cannon Green. This occurred in 2012, ending a five-year drought. The next bonfire happened on November 24, 2013, and was broadcast live over the Internet.


    Princeton’s grounds were designed by Beatrix Farrand between 1912 and 1943. Her contributions were most recently recognized with the naming of a courtyard for her. Subsequent changes to the landscape were introduced by Quennell Rothschild & Partners in 2000. In 2005, Michael Van Valkenburgh was hired as the new consulting landscape architect for the campus. Lynden B. Miller was invited to work with him as Princeton’s consulting gardening architect, focusing on the 17 gardens that are distributed throughout the campus.


    Nassau Hall

    Nassau Hall is the oldest building on campus. Begun in 1754 and completed in 1756, it was the first seat of the New Jersey Legislature in 1776, was involved in the battle of Princeton in 1777, and was the seat of the Congress of the Confederation (and thus capitol of the United States) from June 30, 1783, to November 4, 1783. It now houses the office of the university president and other administrative offices, and remains the symbolic center of the campus. The front entrance is flanked by two bronze tigers, a gift of the Princeton Class of 1879. Commencement is held on the front lawn of Nassau Hall in good weather. In 1966, Nassau Hall was added to the National Register of Historic Places.

    Residential colleges

    Princeton has six undergraduate residential colleges, each housing approximately 500 freshmen, sophomores, some juniors and seniors, and a handful of junior and senior resident advisers. Each college consists of a set of dormitories, a dining hall, a variety of other amenities—such as study spaces, libraries, performance spaces, and darkrooms—and a collection of administrators and associated faculty. Two colleges, First College and Forbes College (formerly Woodrow Wilson College and Princeton Inn College, respectively), date to the 1970s; three others, Rockefeller, Mathey, and Butler Colleges, were created in 1983 following the Committee on Undergraduate Residential Life (CURL) report, which suggested the institution of residential colleges as a solution to an allegedly fragmented campus social life. The construction of Whitman College, the university’s sixth residential college, was completed in 2007.

    Rockefeller and Mathey are located in the northwest corner of the campus; Princeton brochures often feature their Collegiate Gothic architecture. Like most of Princeton’s Gothic buildings, they predate the residential college system and were fashioned into colleges from individual dormitories.

    First and Butler, located south of the center of the campus, were built in the 1960s. First served as an early experiment in the establishment of the residential college system. Butler, like Rockefeller and Mathey, consisted of a collection of ordinary dorms (called the “New New Quad”) before the addition of a dining hall made it a residential college. Widely disliked for their edgy modernist design, including “waffle ceilings,” the dormitories on the Butler Quad were demolished in 2007. Butler is now reopened as a four-year residential college, housing both under- and upperclassmen.

    Forbes is located on the site of the historic Princeton Inn, a gracious hotel overlooking the Princeton golf course. The Princeton Inn, originally constructed in 1924, played regular host to important symposia and gatherings of renowned scholars from both the university and the nearby Institute for Advanced Study for many years. Forbes currently houses nearly 500 undergraduates in its residential halls.

    In 2003, Princeton broke ground for a sixth college named Whitman College after its principal sponsor, Meg Whitman, who graduated from Princeton in 1977. The new dormitories were constructed in the Collegiate Gothic architectural style and were designed by architect Demetri Porphyrios. Construction finished in 2007, and Whitman College was inaugurated as Princeton’s sixth residential college that same year.

    The precursor of the present college system in America was originally proposed by university president Woodrow Wilson in the early 20th century. For over 800 years, however, the collegiate system had already existed in Britain at University of Cambridge (UK) and University of Oxford (UK). Wilson’s model was much closer to Yale University’s present system, which features four-year colleges. Lacking the support of the trustees, the plan languished until 1968. That year, Wilson College was established to cap a series of alternatives to the eating clubs. Fierce debates raged before the present residential college system emerged. The plan was first attempted at Yale, but the administration was initially uninterested; an exasperated alumnus, Edward Harkness, finally paid to have the college system implemented at Harvard in the 1920s, leading to the oft-quoted aphorism that the college system is a Princeton idea that was executed at Harvard with funding from Yale.

    Princeton has one graduate residential college, known simply as the Graduate College, located beyond Forbes College at the outskirts of campus. The far-flung location of the GC was the spoil of a squabble between Woodrow Wilson and then-Graduate School Dean Andrew Fleming West. Wilson preferred a central location for the college; West wanted the graduate students as far as possible from the campus. Ultimately, West prevailed. The Graduate College is composed of a large Collegiate Gothic section crowned by Cleveland Tower, a local landmark that also houses a world-class carillon. The attached New Graduate College provides a modern contrast in architectural style.

    McCarter Theatre

    The Tony-award-winning McCarter Theatre was built by the Princeton Triangle Club, a student performance group, using club profits and a gift from Princeton University alumnus Thomas McCarter. Today, the Triangle Club performs its annual freshmen revue, fall show, and Reunions performances in McCarter. McCarter is also recognized as one of the leading regional theaters in the United States.

    Art Museum

    The Princeton University Art Museum was established in 1882 to give students direct, intimate, and sustained access to original works of art that complement and enrich instruction and research at the university. This continues to be a primary function, along with serving as a community resource and a destination for national and international visitors.

    Numbering over 92,000 objects, the collections range from ancient to contemporary art and concentrate geographically on the Mediterranean regions, Western Europe, China, the United States, and Latin America. There is a collection of Greek and Roman antiquities, including ceramics, marbles, bronzes, and Roman mosaics from faculty excavations in Antioch. Medieval Europe is represented by sculpture, metalwork, and stained glass. The collection of Western European paintings includes examples from the early Renaissance through the 19th century, with masterpieces by Monet, Cézanne, and Van Gogh, and features a growing collection of 20th-century and contemporary art, including iconic paintings such as Andy Warhol’s Blue Marilyn.

    One of the best features of the museums is its collection of Chinese art, with important holdings in bronzes, tomb figurines, painting, and calligraphy. Its collection of pre-Columbian art includes examples of Mayan art, and is commonly considered to be the most important collection of pre-Columbian art outside of Latin America. The museum has collections of old master prints and drawings and a comprehensive collection of over 27,000 original photographs. African art and Northwest Coast Indian art are also represented. The Museum also oversees the outdoor Putnam Collection of Sculpture.

    University Chapel

    The Princeton University Chapel is located on the north side of campus, near Nassau Street. It was built between 1924 and 1928, at a cost of $2.3 million [approximately $34.2 million in 2020 dollars]. Ralph Adams Cram, the University’s supervising architect, designed the chapel, which he viewed as the crown jewel for the Collegiate Gothic motif he had championed for the campus. At the time of its construction, it was the second largest university chapel in the world, after King’s College Chapel, Cambridge. It underwent a two-year, $10 million restoration campaign between 2000 and 2002.

    Measured on the exterior, the chapel is 277 feet (84 m) long, 76 feet (23 m) wide at its transepts, and 121 feet (37 m) high. The exterior is Pennsylvania sandstone, with Indiana limestone used for the trim. The interior is mostly limestone and Aquia Creek sandstone. The design evokes an English church of the Middle Ages. The extensive iconography, in stained glass, stonework, and wood carvings, has the common theme of connecting religion and scholarship.

    The Chapel seats almost 2,000. It hosts weekly ecumenical Christian services, daily Roman Catholic mass, and several annual special events.

    Murray-Dodge Hall

    Murray-Dodge Hall houses the Office of Religious Life (ORL), the Murray Dodge Theater, the Murray-Dodge Café, the Muslim Prayer Room and the Interfaith Prayer Room. The ORL houses the office of the Dean of Religious Life, Alison Boden, and a number of university chaplains, including the country’s first Hindu chaplain, Vineet Chander; and one of the country’s first Muslim chaplains, Sohaib Sultan.


    Published in 2008, Princeton’s Sustainability Plan highlights three priority areas for the University’s Office of Sustainability: reduction of greenhouse gas emissions; conservation of resources; and research, education, and civic engagement. Princeton has committed to reducing its carbon dioxide emissions to 1990 levels by 2020: Energy without the purchase of offsets. The University published its first Sustainability Progress Report in November 2009. The University has adopted a green purchasing policy and recycling program that focuses on paper products, construction materials, lightbulbs, furniture, and electronics. Its dining halls have set a goal to purchase 75% sustainable food products by 2015. The student organization “Greening Princeton” seeks to encourage the University administration to adopt environmentally friendly policies on campus.


    The Trustees of Princeton University, a 40-member board, is responsible for the overall direction of the University. It approves the operating and capital budgets, supervises the investment of the University’s endowment and oversees campus real estate and long-range physical planning. The trustees also exercise prior review and approval concerning changes in major policies, such as those in instructional programs and admission, as well as tuition and fees and the hiring of faculty members.

    With an endowment of $26.1 billion, Princeton University is among the wealthiest universities in the world. Ranked in 2010 as the third largest endowment in the United States, the university had the greatest per-student endowment in the world (over $2 million for undergraduates) in 2011. Such a significant endowment is sustained through the continued donations of its alumni and is maintained by investment advisers. Some of Princeton’s wealth is invested in its art museum, which features works by Claude Monet, Vincent van Gogh, Jackson Pollock, and Andy Warhol among other prominent artists.


    Undergraduates fulfill general education requirements, choose among a wide variety of elective courses, and pursue departmental concentrations and interdisciplinary certificate programs. Required independent work is a hallmark of undergraduate education at Princeton. Students graduate with either the Bachelor of Arts (A.B.) or the Bachelor of Science in Engineering (B.S.E.).

    The graduate school offers advanced degrees spanning the humanities, social sciences, natural sciences, and engineering. Doctoral education is available in most disciplines. It emphasizes original and independent scholarship whereas master’s degree programs in architecture, engineering, finance, and public affairs and public policy prepare candidates for careers in public life and professional practice.

    The university has ties with the Institute for Advanced Study, Princeton Theological Seminary and the Westminster Choir College of Rider University .


    Undergraduate courses in the humanities are traditionally either seminars or lectures held 2 or 3 times a week with an additional discussion seminar that is called a “precept.” To graduate, all A.B. candidates must complete a senior thesis and, in most departments, one or two extensive pieces of independent research that are known as “junior papers.” Juniors in some departments, including architecture and the creative arts, complete independent projects that differ from written research papers. A.B. candidates must also fulfill a three or four semester foreign language requirement and distribution requirements (which include, for example, classes in ethics, literature and the arts, and historical analysis) with a total of 31 classes. B.S.E. candidates follow a parallel track with an emphasis on a rigorous science and math curriculum, a computer science requirement, and at least two semesters of independent research including an optional senior thesis. All B.S.E. students must complete at least 36 classes. A.B. candidates typically have more freedom in course selection than B.S.E. candidates because of the fewer number of required classes. Nonetheless, in the spirit of a liberal arts education, both enjoy a comparatively high degree of latitude in creating a self-structured curriculum.

    Undergraduates agree to adhere to an academic integrity policy called the Honor Code, established in 1893. Under the Honor Code, faculty do not proctor examinations; instead, the students proctor one another and must report any suspected violation to an Honor Committee made up of undergraduates. The Committee investigates reported violations and holds a hearing if it is warranted. An acquittal at such a hearing results in the destruction of all records of the hearing; a conviction results in the student’s suspension or expulsion. The signed pledge required by the Honor Code is so integral to students’ academic experience that the Princeton Triangle Club performs a song about it each fall. Out-of-class exercises fall under the jurisdiction of the Faculty-Student Committee on Discipline. Undergraduates are expected to sign a pledge on their written work affirming that they have not plagiarized the work.


    The Graduate School has about 2,600 students in 42 academic departments and programs in social sciences; engineering; natural sciences; and humanities. These departments include the Department of Psychology; Department of History; and Department of Economics.

    In 2017–2018, it received nearly 11,000 applications for admission and accepted around 1,000 applicants. The University also awarded 319 Ph.D. degrees and 170 final master’s degrees. Princeton has no medical school, law school, business school, or school of education. (A short-lived Princeton Law School folded in 1852.) It offers professional graduate degrees in architecture; engineering; finance and public policy- the last through the Princeton School of Public and International Affairs founded in 1930 as the School of Public and International Affairs and renamed in 1948 after university president (and U.S. president) Woodrow Wilson, and most recently renamed in 2020.


    The Princeton University Library system houses over eleven million holdings including seven million bound volumes. The main university library, Firestone Library, which houses almost four million volumes, is one of the largest university libraries in the world. Additionally, it is among the largest “open stack” libraries in existence. Its collections include the autographed manuscript of F. Scott Fitzgerald’s The Great Gatsby and George F. Kennan’s Long Telegram. In addition to Firestone library, specialized libraries exist for architecture, art and archaeology, East Asian studies, engineering, music, public and international affairs, public policy and university archives, and the sciences. In an effort to expand access, these libraries also subscribe to thousands of electronic resources.


    High Meadows Environmental Institute

    The High Meadows Environmental Institute is an “interdisciplinary center of environmental research, education, and outreach” at the university. The institute was started in 1994. About 90 faculty members at Princeton University are affiliated with it.

    The High Meadows Environmental Institute has the following research centers:

    Carbon Mitigation Initiative (CMI): This is a 15-year-long partnership between PEI and British Petroleum with the goal of finding solutions to problems related to climate change. The Stabilization Wedge Game has been created as part of this initiative.
    Center for BioComplexity (CBC)
    Cooperative Institute for Climate Science (CICS): This is a collaboration with the National Oceanographic and Atmospheric Administration’s Geophysical Fluid Dynamics Laboratory.
    Energy Systems Analysis Group
    Grand Challenges

    Princeton Plasma Physics Laboratory

    The DOE’s Princeton Plasma Physics Laboratory was founded in 1951 as Project Matterhorn, a top-secret cold war project aimed at achieving controlled nuclear fusion. Princeton astrophysics professor Lyman Spitzer became the first director of the project and remained director until the lab’s declassification in 1961 when it received its current name.
    PPPL currently houses approximately half of the graduate astrophysics department, the Princeton Program in Plasma Physics. The lab is also home to the Harold P. Furth Plasma Physics Library. The library contains all declassified Project Matterhorn documents, included the first design sketch of a stellarator by Lyman Spitzer.

    Princeton is one of five US universities to have and to operate a Department of Energy national laboratory.

    Student life and culture

    University housing is guaranteed to all undergraduates for all four years. More than 98% of students live on campus in dormitories. Freshmen and sophomores must live in residential colleges, while juniors and seniors typically live in designated upperclassman dormitories. The actual dormitories are comparable, but only residential colleges have dining halls. Nonetheless, any undergraduate may purchase a meal plan and eat in a residential college dining hall. Recently, upperclassmen have been given the option of remaining in their college for all four years. Juniors and seniors also have the option of living off-campus, but high rent in the Princeton area encourages almost all students to live in university housing. Undergraduate social life revolves around the residential colleges and a number of coeducational eating clubs, which students may choose to join in the spring of their sophomore year. Eating clubs, which are not officially affiliated with the university, serve as dining halls and communal spaces for their members and also host social events throughout the academic year.

    Princeton’s six residential colleges host a variety of social events and activities, guest speakers, and trips. The residential colleges also sponsor trips to New York for undergraduates to see ballets, operas, Broadway shows, sports events, and other activities. The eating clubs, located on Prospect Avenue, are co-ed organizations for upperclassmen. Most upperclassmen eat their meals at one of the eleven eating clubs. Additionally, the clubs serve as evening and weekend social venues for members and guests. The eleven clubs are Cannon; Cap and Gown; Charter; Cloister; Colonial; Cottage; Ivy; Quadrangle; Terrace; Tiger; and Tower.

    Princeton hosts two Model United Nations conferences, PMUNC in the fall for high school students and PDI in the spring for college students. It also hosts the Princeton Invitational Speech and Debate tournament each year at the end of November. Princeton also runs Princeton Model Congress, an event that is held once a year in mid-November. The four-day conference has high school students from around the country as participants.

    Although the school’s admissions policy is need-blind, Princeton, based on the proportion of students who receive Pell Grants, was ranked as a school with little economic diversity among all national universities ranked by U.S. News & World Report. While Pell figures are widely used as a gauge of the number of low-income undergraduates on a given campus, the rankings article cautions “the proportion of students on Pell Grants isn’t a perfect measure of an institution’s efforts to achieve economic diversity,” but goes on to say that “still, many experts say that Pell figures are the best available gauge of how many low-income undergrads there are on a given campus.”

    TigerTrends is a university-based student run fashion, arts, and lifestyle magazine.


    Princeton has made significant progress in expanding the diversity of its student body in recent years. The 2019 freshman class was one of the most diverse in the school’s history, with 61% of students identifying as students of color. Undergraduate and master’s students were 51% male and 49% female for the 2018–19 academic year.

    The median family income of Princeton students is $186,100, with 57% of students coming from the top 10% highest-earning families and 14% from the bottom 60%.

    In 1999, 10% of the student body was Jewish, a percentage lower than those at other Ivy League schools. Sixteen percent of the student body was Jewish in 1985; the number decreased by 40% from 1985 to 1999. This decline prompted The Daily Princetonian to write a series of articles on the decline and its reasons. Caroline C. Pam of The New York Observer wrote that Princeton was “long dogged by a reputation for anti-Semitism” and that this history as well as Princeton’s elite status caused the university and its community to feel sensitivity towards the decrease of Jewish students. At the time many Jewish students at Princeton dated Jewish students at the University of Pennsylvania in Philadelphia because they perceived Princeton as an environment where it was difficult to find romantic prospects; Pam stated that there was a theory that the dating issues were a cause of the decline in Jewish students.

    In 1981, the population of African Americans at Princeton University made up less than 10%. Bruce M. Wright was admitted into the university in 1936 as the first African American, however, his admission was a mistake and when he got to campus he was asked to leave. Three years later Wright asked the dean for an explanation on his dismissal and the dean suggested to him that “a member of your race might feel very much alone” at Princeton University.


    Princeton enjoys a wide variety of campus traditions, some of which, like the Clapper Theft and Nude Olympics, have faded into history:

    Arch Sings – Late-night concerts that feature one or several of Princeton’s undergraduate a cappella groups, such as the Princeton Nassoons; Princeton Tigertones; Princeton Footnotes; Princeton Roaring 20; and The Princeton Wildcats. The free concerts take place in one of the larger arches on campus. Most are held in Blair Arch or Class of 1879 Arch.

    Bonfire – Ceremonial bonfire that takes place in Cannon Green behind Nassau Hall. It is held only if Princeton beats both Harvard University and Yale University at football in the same season. The most recent bonfire was lighted on November 18, 2018.

    Bicker – Selection process for new members that is employed by selective eating clubs. Prospective members, or bickerees, are required to perform a variety of activities at the request of current members.

    Cane Spree – An athletic competition between freshmen and sophomores that is held in the fall. The event centers on cane wrestling, where a freshman and a sophomore will grapple for control of a cane. This commemorates a time in the 1870s when sophomores, angry with the freshmen who strutted around with fancy canes, stole all of the canes from the freshmen, hitting them with their own canes in the process.

    The Clapper or Clapper Theft – The act of climbing to the top of Nassau Hall to steal the bell clapper, which rings to signal the start of classes on the first day of the school year. For safety reasons, the clapper has been removed permanently.

    Class Jackets (Beer Jackets) – Each graduating class designs a Class Jacket that features its class year. The artwork is almost invariably dominated by the school colors and tiger motifs.

    Communiversity – An annual street fair with performances, arts and crafts, and other activities that attempts to foster interaction between the university community and the residents of Princeton.

    Dean’s Date – The Tuesday at the end of each semester when all written work is due. This day signals the end of reading period and the beginning of final examinations. Traditionally, undergraduates gather outside McCosh Hall before the 5:00 PM deadline to cheer on fellow students who have left their work to the very last minute.

    FitzRandolph Gates – At the end of Princeton’s graduation ceremony, the new graduates process out through the main gate of the university as a symbol of the fact that they are leaving college. According to tradition, anyone who exits campus through the FitzRandolph Gates before his or her own graduation date will not graduate.

    Holder Howl – The midnight before Dean’s Date, students from Holder Hall and elsewhere gather in the Holder courtyard and take part in a minute-long, communal primal scream to vent frustration from studying with impromptu, late night noise making.

    Houseparties – Formal parties that are held simultaneously by all of the eating clubs at the end of the spring term.

    Ivy stones – Class memorial stones placed on the exterior walls of academic buildings around the campus.

    Lawnparties – Parties that feature live bands that are held simultaneously by all of the eating clubs at the start of classes and at the conclusion of the academic year.

    Princeton Locomotive – Traditional cheer in use since the 1890s. It is commonly heard at Opening Exercises in the fall as alumni and current students welcome the freshman class, as well as the P-rade in the spring at Princeton Reunions. The cheer starts slowly and picks up speed, and includes the sounds heard at a fireworks show.

    Hip! Hip!
    Rah, Rah, Rah,
    Tiger, Tiger, Tiger,
    Sis, Sis, Sis,
    Boom, Boom, Boom, Ah!
    Princeton! Princeton! Princeton!

    Or if a class is being celebrated, the last line consists of the class year repeated three times, e.g. “Eighty-eight! Eighty-eight! Eighty-eight!”

    Newman’s Day – Students attempt to drink 24 beers in the 24 hours of April 24. According to The New York Times, “the day got its name from an apocryphal quote attributed to Paul Newman: ’24 beers in a case, 24 hours in a day. Coincidence? I think not.'” Newman had spoken out against the tradition, however.

    Nude Olympics – Annual nude and partially nude frolic in Holder Courtyard that takes place during the first snow of the winter. Started in the early 1970s, the Nude Olympics went co-educational in 1979 and gained much notoriety with the American press. For safety reasons, the administration banned the Olympics in 2000 to the chagrin of students.

    Prospect 11 – The act of drinking a beer at all 11 eating clubs in a single night.

    P-rade – Traditional parade of alumni and their families. They process through campus by class year during Reunions.

    Reunions – Massive annual gathering of alumni held the weekend before graduation.


    Princeton supports organized athletics at three levels: varsity intercollegiate, club intercollegiate, and intramural. It also provides “a variety of physical education and recreational programs” for members of the Princeton community. According to the athletics program’s mission statement, Princeton aims for its students who participate in athletics to be “‘student athletes’ in the fullest sense of the phrase. Most undergraduates participate in athletics at some level.

    Princeton’s colors are orange and black. The school’s athletes are known as Tigers, and the mascot is a tiger. The Princeton administration considered naming the mascot in 2007, but the effort was dropped in the face of alumni opposition.


    Princeton is an NCAA Division I school. Its athletic conference is the Ivy League. Princeton hosts 38 men’s and women’s varsity sports. The largest varsity sport is rowing, with almost 150 athletes.

    Princeton’s football team has a long and storied history. Princeton played against Rutgers University in the first intercollegiate football game in the U.S. on Nov 6, 1869. By a score of 6–4, Rutgers won the game, which was played by rules similar to modern rugby. Today Princeton is a member of the Football Championship Subdivision of NCAA Division I. As of the end of the 2010 season, Princeton had won 26 national football championships, more than any other school.

    Club and intramural

    In addition to varsity sports, Princeton hosts about 35 club sports teams. Princeton’s rugby team is organized as a club sport. Princeton’s sailing team is also a club sport, though it competes at the varsity level in the MAISA conference of the Inter-Collegiate Sailing Association.

    Each year, nearly 300 teams participate in intramural sports at Princeton. Intramurals are open to members of Princeton’s faculty, staff, and students, though a team representing a residential college or eating club must consist only of members of that college or club. Several leagues with differing levels of competitiveness are available.


    Notable among a number of songs commonly played and sung at various events such as commencement, convocation, and athletic games is Princeton Cannon Song, the Princeton University fight song.

    Bob Dylan wrote Day of The Locusts (for his 1970 album New Morning) about his experience of receiving an honorary doctorate from the University. It is a reference to the negative experience he had and it mentions the Brood X cicada infestation Princeton experienced that June 1970.

    “Old Nassau”

    Old Nassau has been Princeton University’s anthem since 1859. Its words were written that year by a freshman, Harlan Page Peck, and published in the March issue of the Nassau Literary Review (the oldest student publication at Princeton and also the second oldest undergraduate literary magazine in the country). The words and music appeared together for the first time in Songs of Old Nassau, published in April 1859. Before the Langlotz tune was written, the song was sung to Auld Lang Syne’s melody, which also fits.

    However, Old Nassau does not only refer to the university’s anthem. It can also refer to Nassau Hall, the building that was built in 1756 and named after William III of the House of Orange-Nassau. When built, it was the largest college building in North America. It served briefly as the capitol of the United States when the Continental Congress convened there in the summer of 1783. By metonymy, the term can refer to the university as a whole. Finally, it can also refer to a chemical reaction that is dubbed “Old Nassau reaction” because the solution turns orange and then black.
    Princeton Shield

    “Eos” is the leading source for trustworthy news and perspectives about the Earth and space sciences and their impact. Its namesake is Eos, the Greek goddess of the dawn, who represents the light shed on understanding our planet and its environment in space by the Earth and space sciences.

  • richardmitnick 5:24 pm on January 27, 2023 Permalink | Reply
    Tags: "The Corgi of Exoplanets - Methane Mystery", , , , , Exoplanet HAT-P-18b, Exoplanet research, , ,   

    From AAS NOVA And The NASA/ESA/CSA James Webb Space Telescope: “The Corgi of Exoplanets – Methane Mystery” 


    From AAS NOVA


    NASA Webb Header

    National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) James Webb Infrared Space Telescope annotated, finally launched December 25, 2021, ten years late.

    The NASA/ESA/CSA James Webb Space Telescope

    Ben Cassese

    An artist’s depiction of a transiting exoplanet with an escaping helium tail. [M. Kornmesserr, NASA/ESA Hubble CC BY 4.0]

    With JWST up and running, astronomers are getting a first look at the quirks of individual exoplanets. Features never before examined are coming into view: for instance, a recent study has revealed that while HAT-P-18b may not have much methane, it does have a tiny tail.

    JWST Shows Off, Finds a Corgi

    Now more than a year past its launch, JWST is finally doing what it was designed to do: collecting photons and wowing astronomers with the precision of its data. One of the earliest flexes of its scientific power occurred last summer, when it trained its attention on the transit of a Jupiter-sized, Saturn-mass exoplanet named HAT-P-18b.

    While the team, led by Guangwei Fu (Johns Hopkins University), found several molecules in the upper atmosphere of the planet using the Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument [below], what they didn’t find was more surprising.

    A subsample of the data, orange, and the best-fit model, blue, showing the helium absorption signature. The y-axis is in units of transit depth, meaning enhanced absorption appears as a positive bump. [Fu et al. 2022]

    The first of these surprises was a helium absorption signature, but not surrounding the planet: instead, their results indicate that HAT-P-18b is dragging along a faint tail of escaping helium. Similar features have been spotted trailing behind other planets, but this one was so subtle that it was previously missed by ground based observatories. In other words, HAT-P-18b is the corgi of the exoplanets: it has a tail, but it’s not a dominant structure.

    But what about methane?

    The second surprise concerned a molecule not displaced from the planet, but possibly missing entirely. One of the primary motivations for targeting HAT-P-18b specifically is its position in a uniquely helpful corner of parameter space for modelers working on a methane mystery.

    Hot planets with surface temperatures over 1000K are not expected to have any methane in their atmospheres, since thermodynamics at these extreme conditions prefer other species. However, simple models suggest that any worlds cooler than this should show signs of absorption caused by methane molecules in the upper atmosphere intercepting photons with a specific wavelength.

    Strangely, however, this prediction has not panned out in previous studies. Searches of several planets that should have held methane turned up none. This tension called for a closer look: were the assumptions baked into the models wrong, or was there something strange about the first worlds surveyed? With an equilibrium temperature of 800K, HAT-P-18b was the perfect target to help move the needle one way or another.

    The NIRISS data, black, and several possible model atmospheres to explain it, colored on top. The green and red models were produced assuming equilibrium chemistry. The x-axis denotes wavelength, and the ticks range linearly from 0.5 to 2.5 microns. [Fu et al. 2022]

    Fu and collaborators made no conclusive methane detection, further deepening the model mismatch puzzle. Models which assume the atmosphere is in chemical equilibrium struggled to reproduce the combination of no-methane, yes-water seen in the data, which suggested that some other mechanism(s) were involved to remove the expected gas. Even more striking, other models which made no assumption about an equilibrium also did not confidently prefer including methane in the final fit over leaving it out entirely.

    In all, JWST revealed HAT-P-18b to be a strange world, one which subverts our expectations of atmospheric chemistry but charms with a helium tail. We’ll have to wait for JWST observations of other planets before we know just how weird either of those traits truly is.


    Water and an Escaping Helium Tail Detected in the Hazy and Methane-depleted Atmosphere of HAT-P-18b from JWST NIRISS/SOSS, Guangwei Fu et al 2022 ApJL 940 L35.
    See the science paper for instructive material with images.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The NASA/ESA/CSA James Webb Space Telescope is a large infrared telescope with a 6.5-meter primary mirror. Webb was finally launched December 25, 2021, ten years late. Webb will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb is the world’s largest, most powerful, and most complex space science telescope ever built. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it.

    Webb was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between National Aeronautics and Space Administration, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center managed the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute operates Webb.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There are four science instruments on Webb: The Near InfraRed Camera (NIRCam), The Near InfraRed Spectrograph (NIRspec), The Mid-InfraRed Instrument (MIRI), and The Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS).

    Webb’s instruments are designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.
    National Aeronautics Space Agency Webb NIRCam.

    The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU) Webb MIRI schematic.

    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch was December 25, 2021, ten years late, on an Ariane 5 rocket. The launch was from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb is located at the second Lagrange point, about a million miles from the Earth.

    ESA50 Logo large

    Canadian Space Agency


    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

    The society was founded in 1899 through the efforts of George Ellery Hale. The constitution of the group was written by Hale, George Comstock, Edward Morley, Simon Newcomb and Edward Charles Pickering. These men, plus four others, were the first Executive Council of the society; Newcomb was the first president. The initial membership was 114. The AAS name of the society was not finally decided until 1915, previously it was the “Astronomical and Astrophysical Society of America”. One proposed name that preceded this interim name was “American Astrophysical Society”.

    The AAS today has over 7,000 members and six divisions – the Division for Planetary Sciences (1968); the Division on Dynamical Astronomy (1969); the High Energy Astrophysics Division (1969); the Solar Physics Division (1969); the Historical Astronomy Division (1980); and the Laboratory Astrophysics Division (2012). The membership includes physicists, mathematicians, geologists, engineers and others whose research interests lie within the broad spectrum of subjects now comprising contemporary astronomy.

    In 2019 three AAS members were selected into the tenth anniversary class of TED Fellows.

    The AAS established the AAS Fellows program in 2019 to “confer recognition upon AAS members for achievement and extraordinary service to the field of astronomy and the American Astronomical Society.” The inaugural class was designated by the AAS Board of Trustees and includes an initial group of 232 Legacy Fellows.

  • richardmitnick 9:09 am on January 15, 2023 Permalink | Reply
    Tags: "How Do Rocky Planets Really Form?", , , , , Exoplanet research, , Scientists unveil a unified theory for rocky planet formation, , The large-scale concentration of solid rocky material occurs at a narrow band in the disk called the silicate sublimation line., The new theory identifies this silicate sublimation line band as the likely site for a "planet factory"., The origin of so-called "super-Earths", What single process could have given rise to the rocky planets in our solar system but also to uniform systems of rocky super-Earths?   

    From The California Institute of Technology: “How Do Rocky Planets Really Form?” 

    Caltech Logo

    From The California Institute of Technology

    Robert Perkins
    (626) 395‑1862

    Credit: Konstantin Batygin.

    Scientists unveil a unified theory for rocky planet formation

    A new theory for how rocky planets form could explain the origin of so-called “super-Earths”—a class of exoplanets a few times more massive than the Earth that are the most abundant type of planet in the galaxy.

    Further, it could explain why super-Earths within a single planetary system often wind up looking strangely similar in size, as though each system were only capable of producing a single kind of planet.

    How Rocky Planets Form – Konstantin Batygin.

    “As our observations of exoplanets have grown over the past decade, it has become clear that the standard theory of planet formation needs to be revised, starting with the fundamentals. We need a theory that can simultaneously explain the formation of the terrestrial planets in our solar system as well as the origins of self-similar systems of super-Earths, many of which appear rocky in composition,” says Caltech professor of planetary science Konstantin Batygin (MS ’10, PhD ’12), who collaborated with Alessandro Morbidelli of the Observatoire de la Côte d’Azur in France on the new theory. A paper explaining their work was published by Nature Astronomy [below] on Jan. 12, 2023.

    Planetary systems begin their lifecycles as large spinning disks of gas and dust that consolidate over the course of a few million years or so. Most of the gas accretes into the star at the center of the system, while solid material slowly coalesces into asteroids, comets, planets, and moons.

    In our solar system, there are two distinct types of planets: the smaller rocky inner planets closest to the sun and the outer larger water- and hydrogen-rich gas giants that are farther from the sun. In an earlier study published in Nature Astronomy [below] at the end of 2021, this dichotomy led Morbidelli, Batygin, and colleagues to suggest that planet formation in our solar system occurred in two distinct rings in the protoplanetary disk: an inner one where the small rocky planets formed and an outer one for the more massive icy planets (two of which—Jupiter and Saturn—later grew into gas giants).

    Super-Earths, as the name suggests, are more massive than the Earth. Some even have hydrogen atmospheres, which makes them appear almost gas giant-like. Moreover, they are often found orbiting close to their stars, suggesting that they migrated to their current location from more distant orbits.

    “A few years ago we built a model where super-Earths formed in the icy part of the protoplanetary disk and migrated all the way to the inner edge of the disk, near the star,” says Morbidelli. “The model could explain the masses and orbits of super-Earths but predicted that all are water-rich. Recent observations, however, have demonstrated that most super-Earths are rocky, like the Earth, even if surrounded by a hydrogen atmosphere. That was the death sentence for our old model.”

    Over the past five years, the story has gotten even weirder as scientists—including a team led by Andrew Howard, professor of astronomy at Caltech; Lauren Weiss, assistant professor at the University of Notre Dame; and Erik Petigura, formerly a Sagan Postdoctoral Scholar in Astronomy at Caltech and now a professor at The University of California-Los Angeles—have studied these exoplanets and made an unusual discovery: while there exists a wide variety of types of super-Earths, all of the super-Earths within a single planetary system tend to be similar in terms of orbital spacing, size, mass, and other key features.

    “Lauren discovered that, within a single planetary system, super-Earths are like ‘peas in a pod,'” says Howard, who was not directly connected with the Batygin–Morbidelli paper but has reviewed it. “You basically have a planet factory that only knows how to make planets of one mass, and it just squirts them out one after the other.”

    So, what single process could have given rise to the rocky planets in our solar system but also to uniform systems of rocky super-Earths?

    “The answer turns out to be related to something we figured out in 2020 but didn’t realize applied to planetary formation more broadly,” Batygin says.

    In 2020, Batygin and Morbidelli proposed a new theory [The Astrophysical Journal] for the formation of Jupiter’s four largest moons (Io, Europa, Ganymede, and Callisto). In essence, they demonstrated that, for a specific size range of dust grains, the force dragging the grains toward Jupiter and the force (or entrainment) carrying those grains in an outward flow of gas cancel each other perfectly. That balance in forces created a ring of material that constituted the solid building blocks for the subsequent formation of the moons. Further, the theory suggests that bodies would grow in the ring until they become large enough to exit the ring due to gas-driven migration. After that, they stop growing, which explains why the process produces bodies of similar sizes.

    In their new paper, Batygin and Morbidelli suggest that the mechanism for forming planets around stars is largely the same. In the planetary case, the large-scale concentration of solid rocky material occurs at a narrow band in the disk called the silicate sublimation line — a region where silicate vapors condense to form solid, rocky pebbles. “If you’re a dust grain, you feel considerable headwind in the disk because the gas is orbiting a bit more slowly, and you spiral toward the star; but if you’re in vapor form, you simply spiral outward, together with the gas in the expanding disk. So that place where you turn from vapor into solids is where material accumulates,” Batygin says.

    The new theory identifies this band as the likely site for a “planet factory” that, over time, can produce several similarly sized rocky planets. Moreover, as planets grow sufficiently massive, their interactions with the disk will tend to draw these worlds inward, closer to the star.

    Batygin and Morbidelli’s theory is backed up by extensive computer modeling but began with a simple question. “We looked at the existing model of planet formation, knowing that it does not reproduce what we see, and asked, ‘What assertion are we taking for granted?'” Batygin says. “The trick is to look at something that everybody takes to be true but for no good reason.”

    In this case, the assumption was that solid material is dispersed throughout the protoplanetary disks. By jettisoning that assumption and instead supposing that the first solid bodies form in rings, the new theory can explain different types of planetary systems with a unified framework, Batygin says.

    If the rocky ring contains a lot of mass, planets grow until they migrate away from the ring, resulting in a system of similar super-Earths. If the ring contains little mass, it produces a system that looks much more like our solar system’s terrestrial planets.

    “I’m an observer and an instrument builder, but I pay extremely close attention to the literature,” Howard says. “We get a regular dribble of little-but-still-important contributions. But every five years or so, someone comes out with something that creates a seismic shift in the field. This is one of those papers.”

    Science paper:
    Nature Astronomy
    Nature Astronomy 2021
    The Astrophysical Journal 2020
    See the above science paper for instructive material with images.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The California Institute of Technology is a private research university in Pasadena, California. The university is known for its strength in science and engineering, and is one among a small group of institutes of technology in the United States which is primarily devoted to the instruction of pure and applied sciences.

    The California Institute of Technology was founded as a preparatory and vocational school by Amos G. Throop in 1891 and began attracting influential scientists such as George Ellery Hale, Arthur Amos Noyes, and Robert Andrews Millikan in the early 20th century. The vocational and preparatory schools were disbanded and spun off in 1910 and the college assumed its present name in 1920. In 1934, The California Institute of Technology was elected to the Association of American Universities, and the antecedents of National Aeronautics and Space Administration ‘s Jet Propulsion Laboratory, which The California Institute of Technology continues to manage and operate, were established between 1936 and 1943 under Theodore von Kármán.

    The California Institute of Technology has six academic divisions with strong emphasis on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. First-year students are required to live on campus, and 95% of undergraduates remain in the on-campus House System at The California Institute of Technology. Although The California Institute of Technology has a strong tradition of practical jokes and pranks, student life is governed by an honor code which allows faculty to assign take-home examinations. The The California Institute of Technology Beavers compete in 13 intercollegiate sports in the NCAA Division III’s Southern California Intercollegiate Athletic Conference (SCIAC).

    As of October 2020, there are 76 Nobel laureates who have been affiliated with The California Institute of Technology, including 40 alumni and faculty members (41 prizes, with chemist Linus Pauling being the only individual in history to win two unshared prizes). In addition, 4 Fields Medalists and 6 Turing Award winners have been affiliated with The California Institute of Technology. There are 8 Crafoord Laureates and 56 non-emeritus faculty members (as well as many emeritus faculty members) who have been elected to one of the United States National Academies. Four Chief Scientists of the U.S. Air Force and 71 have won the United States National Medal of Science or Technology. Numerous faculty members are associated with the Howard Hughes Medical Institute as well as National Aeronautics and Space Administration. According to a 2015 Pomona College study, The California Institute of Technology ranked number one in the U.S. for the percentage of its graduates who go on to earn a PhD.


    The California Institute of Technology is classified among “R1: Doctoral Universities – Very High Research Activity”. Caltech was elected to The Association of American Universities in 1934 and remains a research university with “very high” research activity, primarily in STEM fields. The largest federal agencies contributing to research are National Aeronautics and Space Administration; National Science Foundation; Department of Health and Human Services; Department of Defense, and Department of Energy.

    In 2005, The California Institute of Technology had 739,000 square feet (68,700 m^2) dedicated to research: 330,000 square feet (30,700 m^2) to physical sciences, 163,000 square feet (15,100 m^2) to engineering, and 160,000 square feet (14,900 m^2) to biological sciences.

    In addition to managing NASA-JPL/Caltech , The California Institute of Technology also operates the Caltech Palomar Observatory; The Owens Valley Radio Observatory;the Caltech Submillimeter Observatory; the W. M. Keck Observatory at the Mauna Kea Observatory; the Laser Interferometer Gravitational-Wave Observatory at Livingston, Louisiana and Hanford, Washington; and Kerckhoff Marine Laboratory in Corona del Mar, California. The Institute launched the Kavli Nanoscience Institute at The California Institute of Technology in 2006; the Keck Institute for Space Studies in 2008; and is also the current home for the Einstein Papers Project. The Spitzer Science Center, part of the Infrared Processing and Analysis Center located on The California Institute of Technology campus, is the data analysis and community support center for NASA’s Spitzer Infrared Space Telescope [no longer in service].

    The California Institute of Technology partnered with University of California at Los Angeles to establish a Joint Center for Translational Medicine (UCLA-Caltech JCTM), which conducts experimental research into clinical applications, including the diagnosis and treatment of diseases such as cancer.

    The California Institute of Technology operates several Total Carbon Column Observing Network stations as part of an international collaborative effort of measuring greenhouse gases globally. One station is on campus.

  • richardmitnick 8:17 am on January 14, 2023 Permalink | Reply
    Tags: , , , Exoplanet research, , , , The celestial object TOI 700 e   

    From NASA JPL-Caltech Via “Science Alert (AU)” : “NASA Just Discovered a Rare Earth-Sized Planet in a Habitable Zone” 

    From NASA JPL-Caltech



    “Science Alert (AU)”

    David Nield

    Exoplanet TOI 700 e An illustration of how exoplanet TOI 700 e might look (Robert Hurt/NASA/JPL-Caltech.)

    When it comes to finding life outside of our Solar System, planets that closely resemble Earth seem like a good place to start. We can now welcome celestial object TOI 700 e to that group of promising leads.

    TOI 700 e has been confirmed orbiting inside the habitable zone of its star, TOI 700. That’s the region of space where significant quantities of water on its surface would be at a temperature suitable for a liquid form. Too warm for a blanket of ice, yet still cool enough for vapor to condense, these kinds of planets are considered ‘just right’ for life as we know it.

    We can thank NASA’s Transiting Exoplanet Survey Satellite, or TESS, for finding TOI 700 e, and for giving it its name (TOI means TESS Object of Interest).

    It is the second planet in the habitable zone in this system, joining TOI 700 d that was spotted in 2020.

    “This is one of only a few systems with multiple, small, habitable-zone planets that we know of,” says planetary scientist Emily Gilbert, from the NASA Jet Propulsion Laboratory (JPL) in California.

    “That makes the TOI 700 system an exciting prospect for additional follow up. Planet e is about 10 percent smaller than planet d, so the system also shows how additional TESS observations help us find smaller and smaller worlds.”

    TOI 700 is a small, cool star (known as an M dwarf star), located around 100 light-years away from us in the Dorado constellation. These stars are nowhere near as big or as hot as our own Sun, so planets need to be closer to them for conditions to be warm enough for water to avoid freezing.

    As for TOI 700 e, it is believed to be 95 percent the size of Earth and mainly rocky. It sits in the ‘optimistic’ habitable zone – a zone where water may have existed at some point in time. TOI 700 d is in the narrower ‘conservative’ habitable zone, which is where astronomers think liquid water might exist for the majority of a planet’s existence.

    Telescopes see these exoplanets (planets outside our Solar System) as regular blips in the light of their parent stars as they pass in front of it, in what’s known as a transit. With more surface blocking the star’s light, larger planets present easier opportunities to be seen than small, rocky worlds, making Earth-like discoveries like this one a rare treat.

    TOI 700 e takes 28 days to do a single orbit, whereas TOI 700 d – which is a little further out than its neighbor – takes 37 days. As TOI 700 e is smaller than TOI 700 d, it took more data to confirm the silhouette really did represent a new planet.

    “If the star was a little closer or the planet a little bigger, we might have been able to spot TOI 700 e in the first year of TESS data,” says astrophysicist Ben Hord from the University of Maryland. “But the signal was so faint that we needed the additional year of transit observations to identify it.”

    TESS is monitoring around 100 million stars, and so any way we can find to narrow down the search for life is going to be useful. Finding exoplanets in their respective habitable zones is one of the best ways we’ve got of doing that.

    Both TOI 700 e and TOI 700 d are thought to be tidally locked: in other words, one side of the planet is always facing its star (in the same way that the same side of the Moon is always visible from Earth). Having one side of a planet constantly baking in the sunlight does reduce the likelihood of complex life getting off to a smooth start, admittedly.

    Even if these ‘just right’ planets aren’t exactly perfect for life, they do tell us a thing or two about finding solar systems that might be better suited for it. By studying star systems like the one we’re in, astronomers can also better understand the evolution of our home and how neighboring planets came to their current orbits.

    “Even with more than 5,000 exoplanets discovered to date, TOI 700 e is a key example that we have a lot more to learn,” says astronomer Joey Rodriguez from Michigan State University.

    The research has been accepted for publication in The Astrophysical Journal Letters [ https://arxiv.org/pdf/2301.03617.pdf ].

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA JPL-Caltech Campus

    NASA JPL-Caltech is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge, on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

    NASA Deep Space Network. Credit: NASA.

    NASA Deep Space Network Station 56 Madrid Spain added in early 2021.

    NASA Deep Space Network Station 14 at Goldstone Deep Space Communications Complex in California

    NASA Canberra Deep Space Communication Complex, AU, Deep Space Network. Credit: NASA

    NASA Deep Space Network Madrid Spain. Credit: NASA.

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from the[JAXA]Greenhouse Gases Observing Satellite.

  • richardmitnick 10:55 pm on January 11, 2023 Permalink | Reply
    Tags: "Webb Confirms Its First Exoplanet", 2022., , , , Exoplanet research, , , The rocky exoplanet LHS 475 b was captured by Webb’s NIRSpec instrument on August 31   

    From The NASA/ESA/CSA James Webb Space Telescope: “Webb Confirms Its First Exoplanet” 

    NASA Webb Header

    National Aeronautics Space Agency/European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU)/ Canadian Space Agency [Agence Spatiale Canadienne](CA) James Webb Infrared Space Telescope annotated, finally launched December 25, 2021, ten years late.

    From The NASA/ESA/CSA James Webb Space Telescope



    Claire Blome
    Space Telescope Science Institute, Baltimore, Maryland

    Christine Pulliam
    Space Telescope Science Institute, Baltimore, Maryland

    Exoplanet LHS 475 b and Its Star (Illustration)

    This illustration reflects that exoplanet LHS 475 b is rocky and almost precisely the same size as Earth based on new evidence from NASA’s James Webb Space Telescope. The planet is only a few hundred degrees warmer than our home planet.

    The planet whips around its star in just two days, far faster than any planet in the solar system, but its red dwarf star is less than half the temperature of the Sun. Researchers will follow up this summer with another observation with Webb, which they hope will allow them to definitively conclude if the planet has an atmosphere.

    LHS 475 b is relatively close, 41 light-years away, in the constellation Octans.

    This illustration is based on observations from Webb. Webb has not captured a direct image of this planet.


    Exoplanet LHS 475 b (NIRSpec Transit Light Curve)

    How do researchers spot a distant planet? By observing the changes in light as it orbits its star.

    A light curve from NASA’s James Webb Space Telescope’s Near-Infrared Spectrograph (NIRSpec) [below] shows the change in brightness from the LHS 475 star system over time as the planet transited the star on August 31, 2022.

    This observation was made using NIRSpec’s bright object time-series mode, which uses a grating to spread out light from a single bright object (like the star LHS 475) and measure the brightness of each wavelength of light at set intervals of time. The data show that LHS 475 b is 99% the diameter of Earth and therefore rocky.

    To capture these data, Webb stared at the LHS 475 star system for almost 3 hours, beginning about 1.5 hours before the transit and ending about 30 minutes after the transit. The transit itself lasted about 40 minutes. The curve shown here includes a total of 1,158 individual brightness measurements – about one every nine seconds.

    LHS 475 b is a rocky, Earth-sized exoplanet that orbits a red dwarf star roughly 41 light-years away in the constellation Octans. The planet is extremely close to its star, completing one orbit in two Earth-days. The planet’s confirmation was made possible by Webb’s data.

    The background illustration of LHS 475 b and its star is based on our current understanding of the planet from Webb spectroscopy. Webb has not captured a direct image of the planet or its atmosphere.

    NIRSpec was built for the European Space Agency (ESA) by a consortium of European companies led by Airbus Defence and Space (ADS) with NASA’s Goddard Space Flight Center providing its detector and micro-shutter subsystems.

    SCIENCE: Kevin B. Stevenson (APL), Jacob A. Lustig-Yaeger (APL), Erin M. May (APL), Guangwei Fu (JHU), Sarah E. Moran (University of Arizona)

    Exoplanet LHS 475 b (Transmission Spectrum)

    A flat line in a transmission spectrum, like this one, can be exciting – it can tell us a lot about the planet.

    Researchers used NASA’s James Webb Space Telescope’s Near-Infrared Spectrograph (NIRSpec) to observe exoplanet LHS 475 b. As this spectrum shows, Webb did not observe a detectable quantity of any element or molecule. Common signatures in a hydrogen-dominated atmosphere, for example, would indicate a light, gaseous atmosphere. Those elements were not detected in LHS 475 b’s spectrum.

    The green line represents a pure methane atmosphere, which is not favored since if methane were present, it would be expected to block more starlight at 3.3 microns. The yellow line represents the best-fit model for a featureless spectrum that contains no evidence of the planet’s atmosphere. This model is representative of a planet that has no atmosphere.

    The purple line represents a pure carbon dioxide atmosphere and is indistinguishable from a flat line at the current level of precision. An atmosphere made up of pure carbon dioxide is far more difficult to detect, even for Webb’s advanced instruments. “We require very, very precise data to be able to distinguish a pure carbon dioxide atmosphere from no atmosphere at all,” explained Jacob Lustig-Yaeger of the Johns Hopkins University Applied Physics Laboratory. “A pure carbon dioxide atmosphere may be thin like the one on Mars making it difficult to detect.”

    The researchers studying LHS 475 b suggest that an additional, upcoming observation may act as a “tie breaker,” allowing them to identify any presence of carbon dioxide – or any other molecule – or rule everything out and conclude the planet has no atmosphere. Quite simply, additional data are required before a conclusion can be made.

    This transmission spectrum of the rocky exoplanet LHS 475 b was captured by Webb’s NIRSpec instrument on August 31, 2022. A transmission spectrum is made by comparing starlight filtered through a planet’s atmosphere as it moves in front of the star to the unfiltered starlight detected when the planet is beside the star. Each of the 56 data points on this graph represents the amount of light that the planet blocks from the star at a different wavelength of light. The data would reveal molecules in the planet’s atmosphere by showing that they increase the apparent size of the planet at only specific wavelengths. No such atmospheric features are observed in this spectrum.

    The gray lines extending above and below each data point are error bars that show the uncertainty of each measurement, or the reasonable range of actual possible values. For a single observation, the error on these measurements is extremely small (30 to 50 parts per million).

    The observation was made using the NIRSpec bright object time-series mode, which uses a grating to spread out light from a single bright object (like the star LHS 475) and measure the brightness of each wavelength at set intervals of time.

    LHS 475 b is a rocky exoplanet approximately that same size as Earth. It orbits a red dwarf star roughly 41 light-years away in the constellation Octans. The planet orbits extremely close to its star and completes one orbit in two Earth-days. The planet’s discovery was confirmed with data from the Webb Telescope.

    The background illustration of LHS 475 b and its star is based on current understanding of the planet from Webb spectroscopy. Webb has not captured a direct image of the planet or its atmosphere.

    NIRSpec was built for the European Space Agency (ESA) by a consortium of European companies led by Airbus Defence and Space (ADS) with NASA’s Goddard Space Flight Center providing its detector and micro-shutter subsystems.

    SCIENCE: Kevin B. Stevenson (APL), Jacob A. Lustig-Yaeger (APL), Erin M. May (APL), Guangwei Fu (JHU), Sarah E. Moran (University of Arizona)

    The planet is rocky and almost precisely the same size as Earth, but whips around its star in only two days.

    Researchers using NASA’s James Webb Space Telescope have formally embarked on a new frontier: Identifying and analyzing rocky exoplanets that orbit red dwarf stars. A team led by Kevin Stevenson and Jacob Lustig-Yaeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, confirmed that LHS 475 b not only exists, it is a small, rocky planet that is almost exactly the same size as Earth. Before Webb, researchers typically targeted planets that are larger than Jupiter, which is 11 times wider than Earth. This will inevitably be the first of many discoveries Webb data will help researchers make as they continue exploring planets elsewhere in our Milky Way galaxy.
    Researchers confirmed an exoplanet, a planet that orbits another star, using NASA’s James Webb Space Telescope for the first time. Formally classified as LHS 475 b, the planet is almost exactly the same size as our own, clocking in at 99% of Earth’s diameter. The research team is led by Kevin Stevenson and Jacob Lustig-Yaeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

    The team chose to observe this target with Webb after carefully reviewing targets of interest from NASA’s Transiting Exoplanet Survey Satellite (TESS), which hinted at the planet’s existence. Webb’s Near-Infrared Spectrograph (NIRSpec) captured the planet easily and clearly with only two transit observations. “There is no question that the planet is there. Webb’s pristine data validate it,” said Lustig-Yaeger. “The fact that it is also a small, rocky planet is impressive for the observatory,” Stevenson added.

    “These first observational results from an Earth-size, rocky planet open the door to many future possibilities for studying rocky planet atmospheres with Webb,” agreed Mark Clampin, Astrophysics Division director at NASA Headquarters in Washington. “Webb is bringing us closer and closer to a new understanding of Earth-like worlds outside our solar system, and the mission is only just getting started.”

    Among all operating telescopes, only Webb is capable of characterizing the atmospheres of Earth-sized exoplanets. The team attempted to assess what is in the planet’s atmosphere by analyzing its transmission spectrum. Although the data show that this is an Earth-sized terrestrial planet, they do not yet know if it has an atmosphere. “The observatory’s data are beautiful,” said Erin May, also of the Johns Hopkins University Applied Physics Laboratory. “The telescope is so sensitive that it can easily detect a range of molecules, but we can’t yet make any definitive conclusions about the planet’s atmosphere.”

    Although the team can’t conclude what is present, they can definitely say what is not present. “There are some terrestrial-type atmospheres that we can rule out,” explained Lustig-Yaeger. “It can’t have a thick methane-dominated atmosphere, similar to that of Saturn’s moon Titan.”

    The team also notes that while it’s possible the planet has no atmosphere, there are some atmospheric compositions that have not been ruled out, such as a pure carbon dioxide atmosphere. “Counterintuitively, a 100% carbon dioxide atmosphere is so much more compact that it becomes very challenging to detect,” said Lustig-Yaeger. Even more precise measurements are required for the team to distinguish a pure carbon dioxide atmosphere from no atmosphere at all. The researchers are scheduled to obtain additional spectra with upcoming observations this summer.

    Webb also revealed that the planet is a few hundred degrees warmer than Earth, so if clouds are detected, it may lead the researchers to conclude that the planet is more like Venus, which has a carbon dioxide atmosphere and is perpetually shrouded in thick clouds. “We’re at the forefront of studying small, rocky exoplanets,” Lustig-Yaeger said. “We have barely begun scratching the surface of what their atmospheres might be like.”

    The researchers also confirmed that the planet completes an orbit in just two days, information that was almost instantaneously revealed by Webb’s precise light curve. Although LHS 475 b is closer to its star than any planet in our solar system, its red dwarf star is less than half the temperature of the Sun, so the researchers project it still could have an atmosphere.

    The researchers’ findings have opened the possibilities of pinpointing Earth-sized planets orbiting smaller red dwarf stars. “This rocky planet confirmation highlights the precision of the mission’s instruments,” Stevenson said. “And it is only the first of many discoveries that it will make.” Lustig-Yaeger agreed. “With this telescope, rocky exoplanets are the new frontier.”

    LHS 475 b is relatively close, at only 41 light-years away, in the constellation Octans.

    The team’s results were presented at a press conference of the American Astronomical Society (AAS) on Wednesday, Jan. 11, 2023.

    See the full article here .

    Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct. Use “Reply”


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The NASA/ESA/CSA James Webb Space Telescope is a large infrared telescope with a 6.5-meter primary mirror. Webb was finally launched December 25, 2021, ten years late. Webb will be the premier observatory of the next decade, serving thousands of astronomers worldwide. It will study every phase in the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of solar systems capable of supporting life on planets like Earth, to the evolution of our own Solar System.

    Webb is the world’s largest, most powerful, and most complex space science telescope ever built. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it.

    Webb was formerly known as the “Next Generation Space Telescope” (NGST); it was renamed in Sept. 2002 after a former NASA administrator, James Webb.

    Webb is an international collaboration between National Aeronautics and Space Administration, the European Space Agency (ESA), and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center managed the development effort. The main industrial partner is Northrop Grumman; the Space Telescope Science Institute operates Webb.

    Several innovative technologies have been developed for Webb. These include a folding, segmented primary mirror, adjusted to shape after launch; ultra-lightweight beryllium optics; detectors able to record extremely weak signals, microshutters that enable programmable object selection for the spectrograph; and a cryocooler for cooling the mid-IR detectors to 7K.

    There are four science instruments on Webb: The Near InfraRed Camera (NIRCam), The Near InfraRed Spectrograph (NIRspec), The Mid-InfraRed Instrument (MIRI), and The Fine Guidance Sensor/ Near InfraRed Imager and Slitless Spectrograph (FGS-NIRISS).

    Webb’s instruments are designed to work primarily in the infrared range of the electromagnetic spectrum, with some capability in the visible range. It will be sensitive to light from 0.6 to 28 micrometers in wavelength.
    National Aeronautics Space Agency Webb NIRCam.

    The European Space Agency [La Agencia Espacial Europea] [Agence spatiale européenne][Europäische Weltraumorganization](EU) Webb MIRI schematic.

    Webb has four main science themes: The End of the Dark Ages: First Light and Reionization, The Assembly of Galaxies, The Birth of Stars and Protoplanetary Systems, and Planetary Systems and the Origins of Life.

    Launch was December 25, 2021, ten years late, on an Ariane 5 rocket. The launch was from Arianespace’s ELA-3 launch complex at European Spaceport located near Kourou, French Guiana. Webb is located at the second Lagrange point, about a million miles from the Earth.

    ESA50 Logo large

    Canadian Space Agency

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