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  • richardmitnick 12:39 pm on September 10, 2021 Permalink | Reply
    Tags: "Satellite in sun’s backyard unravels the origins of interplanetary dust", NASA's Parker Solar Probe,   

    From Princeton University (US) and NASA Parker Solar Probe : “Satellite in sun’s backyard unravels the origins of interplanetary dust” 

    Princeton University

    From Princeton University (US)

    and

    NASA Parker Solar Probe

    From Princeton:

    Sept. 9, 2021
    Liz Fuller-Wright

    What do shooting stars and astronaut safety have in common?

    Both stem from the sub-microscopic rock fragments found throughout the solar system, sometimes called interplanetary dust.

    When these particles collide with Earth’s atmosphere, they create meteors, better known as shooting stars, as the (usually) microscopic fragments vaporize and leave flaming trails through the air. When they collide with astronauts, they can puncture holes in space suits — or worse. Understanding the sources and patterns of this interplanetary dust is therefore very important to NASA, as it plans for missions to the moon, Mars and beyond.

    During its revolutions around the sun, the Parker Solar Probe spacecraft, the mission going closer to the sun than anything in spacefaring history, is bombarded by these dust particles.

    When crashing onto the spacecraft, the tiny grains — some as small as a ten-thousandth of a millimeter across — vaporize and release a cloud of electrically charged particles that can be detected by FIELDS, a suite of instruments designed to detect electric and magnetic fields.

    A pair of papers publishing this week in the Planetary Science Journal use FIELDS data to take an up-close look at the “zodiacal cloud,” the collective term for these tiny particles.

    Collisional Evolution of the Inner Zodiacal Cloud

    Dust Directionality and an Anomalous Interplanetary Dust Population Detected by the Parker Solar Probe

    “Every solar system has a zodiacal cloud, and we actually get to explore ours and understand how it works,” said Jamey Szalay, an associate research scholar in astrophysical sciences at Princeton who is the lead author on one of the papers. “Understanding the evolution and dynamics of our zodiacal cloud will allow us to better understand every zodiacal observation we’ve seen around any other solar system.”

    The zodiacal cloud scatters sunlight in a way that can be seen with the naked eye, but only on very dark, clear nights, as moonlight or light from cities both easily outshine it. Thickest near the sun and thinnest near the edges of the solar system, the zodiacal cloud looks smooth to the naked eye, but infrared wavelengths reveal bright streaks and ribbons that can be traced back to their sources: comets and asteroids.

    With data from Parker’s first six orbits, together with computer modeling of the particle motion in the inner solar system, Szalay and his colleagues disentangled those streaks and ribbons to reveal two different populations of dust in the zodiacal cloud: the tiny grains ever-so-slowly spiraling in towards the sun over thousands to millions of years, known as alpha-meteoroids; and then, as the swirling cloud gets denser, the larger grains collide and create ever-smaller fragments known as beta-meteoroids that are subsequently pushed away from the sun by the pressure from sunlight.

    Yes, sunlight.

    And not just nudged a bit, either. “When a fragment becomes small enough, radiation pressure — solar light — is actually strong enough to blow it out of the solar system,” Szalay said.

    “The existence of such tiny grains was repeatedly reported from dedicated spacecraft dust measurements in the region between Earth and Mars, but never in the inner solar system where these particles were thought to originate,” said Harald Krüger, a zodiacal dust expert with the MPG Institute for Solar System Research [Max-Planck-Institut für Sonnensystemforschung] (DE) and a co-author on Szalay’s paper. “Thus, the FIELDS instrument offers a new window to study these solar light-driven dust particles close to their source region.”

    FIELDS also detected a narrow stream of particles that appeared to be released from a discrete source, forming a delicate structure in the zodiacal dust cloud. To understand this third component, Szalay went back to the origins of the zodiacal dust: comets and asteroids.

    Comets, dust-filled snowballs traveling through our solar system in long, elliptical orbits, eject copious amounts of dust when they get close enough to the sun to start vaporizing their ice and dry ice. Asteroids, large and small rocks orbiting the sun between Mars and Jupiter, release dust when they collide with each other. Some of these grains are knocked off in any direction, but most are trapped in the orbits of their parent body, explained Szalay, meaning that over the course of thousands of orbits, a comet’s track becomes more like a gravel road than an empty path with one shining orb and a bright trail. (Over millions of orbits, the grains will scatter beyond their orbital path, merging into the zodiacal background cloud.)

    Szalay refers to these dust-strewn paths as “tubes” of cometary or asteroidal debris. “If Earth crosses that tube in any place, we get a meteor shower,” he said.

    He theorized that the Parker Solar Probe may have traveled through one of these. “Maybe there’s a dense tube that we just couldn’t have observed any other way other than by Parker literally flying through and getting sandblasted by it,” he said.

    But the tubes closest to Parker’s path didn’t seem to have enough material to cause the data spike. So Szalay proposed another theory. Maybe one of these meteoroid tubes — most likely the Geminids, which every December cause one of Earth’s most intense meteor showers — was colliding at high speeds against the inner zodiacal cloud itself. The impacts between the tube and zodiacal dust could produce large quantities of beta-meteoroids that don’t blast off in random directions, but are focused into a narrow set of paths.

    “We’ve termed this a ‘beta-stream,’ which is a new contribution to the field,” Szalay said. “These beta-streams are expected to be a fundamental physical process at all circumstellar planetary disks.”

    “One of the important aspects of this article is the fact that Parker Solar Probe is the first spacecraft that reaches so close to the Sun that it penetrates the regions where mutual particle collisions are the most frequent,” said Petr Pokorný, a zodiacal cloud modeler with NASA and the Catholic University of America, who was a co-author on Szalay’s paper. “Mutual particle collisions are important not only in our solar system, but in all exosolar systems. This article gives the modeling community a unique insight into this previously uncharted territory.”

    “Parker essentially experienced its own meteor shower,” Szalay said. “It either flew through one of those tubes of material, or it flew through a beta-stream.”

    The stream was also spotted by Anna Pusack, then an undergraduate at the University of Colorado-Boulder. “I saw this wedge-like shape in my data, and my advisor, David Malaspina, suggested I present the work to Jamey,” she said. “The wedge shape seemed to indicate a strong spray, or what Jamey called a beta-stream in his new models, of small particles hitting the spacecraft in a very directed manner. This was incredible for me, to connect the data I had analyzed to theoretical work done on the other side of the country. For a young scientist, it really sparked all the excitement and possibility that can come from collaborative work.”

    Pusack is the lead author on the paper being published jointly with Szalay’s. “These papers really do go hand in hand,” she said. “The data supports the models, and the models help explain the data.”

    “This is a tremendous contribution to our understanding of the zodiacal cloud, the near-sun dust environment more broadly, and the dust risks to NASA’s Parker Solar Probe mission,” said David McComas, a professor of astrophysical sciences at Princeton University and the vice president for the Princeton Plasma Physics Laboratory, who is the principal investigator for ISʘIS, another instrument on board Parker Solar Probe, and for the upcoming Interstellar Mapping and Acceleration Probe (IMAP) mission.

    From National Aeronautics Space Agency (US):

    Scientists using data from NASA’s Parker Solar Probe [above] have assembled a comprehensive picture of the structure and behavior of the large cloud of space dust that swirls through the innermost solar system – and the new insight offers clues to similar clouds around stars across the universe.

    Research teams led by Jamey Szalay of Princeton University and Anna Pusack of University of Colorado (US), Laboratory for Atmospheric and Space Physics took advantage of Parker Solar Probe’s flight path – an orbit that swings it closer to Sun than any spacecraft in history – to get the best direct look yet at the most active region of the zodiacal cloud, a dusty cloud of grains shed from passing comets and asteroids. The teams published their findings Sep. 9 in the Planetary Science Journal [above].

    “Every stellar system has a zodiacal cloud, and we actually get to explore ours and understand how it works,” said Szalay. “Understanding the evolution and dynamics of our zodiacal cloud will allow us to better understand every zodiacal observation we’ve seen around any other stellar system.”

    Built and operated by the Johns Hopkins Applied Physics Laboratory (US) in Laurel, Maryland, Parker Solar Probe does not carry a dedicated dust counter that would give it accurate readings on grain mass, composition, speed and direction. But as dust grains pepper the spacecraft along its path, the high-velocity impacts create plasma clouds. These impact clouds produce unique signals in electric potential that are picked up by several sensors on the probe’s FIELDS instrument, which is designed to measure the electric and magnetic fields near the Sun.

    Gathering data from Parker Solar Probe’s first six orbits around the Sun, the researchers saw impacts that were consistent with the two primary dust populations in the cloud. The first population makes up the bulk of the zodiacal cloud: most of the grains are being slowly pulled in toward the Sun over thousands to millions of years; then, as the swirling cloud gets denser, the larger grains collide and create fragments that, if small enough, are pushed out of the solar system in all directions by pressure from sunlight. This second population of smaller fragments are called beta-meteoroids.

    “There are two populations of material that are part of the same story on how the cloud evolves, and with Parker Solar Probe we were able get the closest look yet at the most intense region,” Szalay said. “It was really exciting that we got to measure not just the cloud itself, but the way it loses material.”

    But it was readings from Parker Solar Probe’s fourth and fifth orbits – which were a step closer than the first three – that really got the researchers’ attention. As the spacecraft sped away from the Sun, it picked up an enhancement in dust detections that didn’t match the two-component model, a tip that another dust population may be in the area, less than a third of Earth’s distance from the Sun.

    One idea was that the spacecraft flew through a “tube” of materials called a meteoroid stream, causing a spike in dust impacts – much like how we see a meteor shower when Earth moves through one of these streams. But the closest streams didn’t seem to have enough material to cause the enhancement. So the team went in a different direction: One of these meteoroid streams – most likely the Geminids stream, which each December causes one of the most intense meteor showers at Earth – was colliding at high speeds into the inner zodiacal cloud itself. These impacts with zodiacal dust produce large quantities of beta-meteoroids that don’t blast off in random directions, but are focused into a narrow set of paths.

    “The idea is that a meteoroid stream is colliding with and spraying out material all along its orbit in a tangential direction, and we’ve called that a beta-stream,” Szalay said. “What’s exciting about this concept is that it’s a fundamental process that would be occurring not only at every meteoroid stream in our solar system, but with every meteoroid stream to varying degrees in every dust cloud in the universe.”

    Fortuitously, during Parker Solar Probe’s fourth orbit, the FIELDS instrument was configured to indicate from which direction meteoroids were hitting the spacecraft. By looking at this data, Pusack and colleagues also concluded the enhancement is consistent with a Geminids beta-stream, and found considerable substructure in this signature that may allow researchers to better characterize this interesting phenomenon.

    “The data show distinct dust impacts hitting the spacecraft from behind, indicating particles that would have to catch up and exceed the speed of the spacecraft,” said Pusack.

    The researchers added that these measurements have already helped them to better understand the collisional evolution of our solar system’s dust cloud, in a region previously unexplored by any spacecraft, and may also very well have provided direct observations of how a meteoroid stream collides with, and erodes, our zodiacal cloud.

    “The amazing thing about all of this is that our mission is just getting started,” said Nour E. Raouafi, Parker Solar Probe project scientist at APL. “In only three years since launch, we have already learned so much about the environment near the Sun, from the behavior of the zodiacal cloud, to the structure of the solar wind that streams throughout the solar system, to the processes that heat and accelerate the solar wind itself. And as this durable spacecraft speeds even closer to the Sun – actually flying through its atmosphere – we can’t wait to see what other discoveries await us.”

    Launched Aug. 12, 2018, Parker Solar Probe recently completed its ninth solar orbit, which took it to within 6.5 million miles of the Sun’s surface. The probe will ultimately come to within 3.8 million miles of the solar surface, making three close passes in 2024 and 2025 at speeds exceeding 430,000 miles per hour – and its heat shield facing temperatures higher than 2,500 degrees Fahrenheit.

    Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The program is managed by NASA’s Goddard Space Flight Center for the Heliophysics Division of NASA’s Science Mission Directorate. APL manages the Parker Solar Probe mission for NASA. The FIELDS instrument suite is led by The University of California-Berkeley (US).

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, designed, built and operates the spacecraft.

    For more information about Parker, visit:

    https://www.nasa.gov/parker

    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.

    About Princeton: Overview

    Princeton University (US) 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 (US), 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.

    Coeducation

    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 (US) and University of Pennsylvania(US)) 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.

    Landscape

    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.

    Buildings

    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 Cambridge and Oxford Universities. Wilson’s model was much closer to Yale University (US)’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.

    Sustainability

    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.

    Organization

    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.

    Academics

    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 (US).

    Undergraduate

    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.

    Graduate

    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.

    Libraries

    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.

    Institutes

    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 Princeton Plasma Physics Laboratory, PPPL, 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(US) 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.

    Demographics

    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.

    Traditions

    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.

    Athletics

    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.

    Varsity

    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.

    Songs

    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

     
  • richardmitnick 8:17 pm on February 3, 2020 Permalink | Reply
    Tags: NASA's Parker Solar Probe, ,   

    From Southwest Research Institute: “SwRI-led team identifies low-energy solar particles from beyond Earth in the near-Sun environment” 

    SwRI bloc

    From Southwest Research Institute

    February 3, 2020

    Using data from NASA’s Parker Solar Probe (PSP), a team led by Southwest Research Institute identified low-energy particles lurking near the Sun that likely originated from solar wind interactions well beyond Earth orbit.

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker

    PSP is venturing closer to the Sun than any previous probe, carrying hardware SwRI helped develop. Scientists are probing the enigmatic features of the Sun to answer many questions, including how to protect space travelers and technology from the radiation associated with solar events.

    “Our main goal is to determine the acceleration mechanisms that create and transport dangerous high-energy particles from the solar atmosphere into the solar system, including the near-Earth environment,” said Dr. Mihir Desai, a mission co-investigator on the Integrated Science Investigation of the Sun (IS☉IS) instrument suite, a multi-institutional project led by Principal Investigator Prof. Dave McComas of Princeton University. IS☉IS consists of two instruments, Energetic Particle Instrument-High (EPI-Hi) and Energetic Particle Instrument-Low (EPI-Lo). “With EPI-Lo, we were able to measure extremely low-energy particles unexpectedly close to the solar environment. We considered many explanations for their presence, but ultimately determined they are the smoking gun pointing to interactions between slow- and fast-moving regions of the solar wind that accelerate high-energy particles from beyond the orbit of Earth. Some of those travel back toward the Sun, slowing against the tide of the outpouring solar wind but still retaining surprisingly high energies.”

    PSP, which will travel within 4 million miles of the Sun’s surface, is collecting new solar data to help scientists understand how solar events, such as coronal mass ejections, impact life on Earth. During the rising portion of the Sun’s activity cycle, our star releases huge quantities of energized matter, magnetic fields and electromagnetic radiation in the form of coronal mass ejections (CMEs). This material is integrated into the solar wind, the steady stream of charged particles released from the Sun’s upper atmosphere. The high-energy solar energetic particles (SEPs) present a serious radiation threat to human explorers living and working outside low-Earth orbit and to technological assets such as communications and scientific satellites in space. The mission is making the first-ever direct measurements of both the low-energy source populations as well as the more hazardous, higher energy particles in the near-Sun environment, where the acceleration takes place.

    2
    SwRI-led team identified low-energy particles, the smoking gun pointing to interactions between slow- and fast-moving regions of the solar wind accelerating high-energy particles from beyond the orbit of Earth. Using Integrated Science Investigation of the Sun (IS☉IS) instrument data, they measured low-energy particles in the near-Sun environment that had likely traveled back toward the Sun, slowing against the tide of the solar wind while still retaining surprising energies.

    When the Sun’s activity reaches a lull, roughly about every 11 years, solar equatorial regions emit slower solar wind streams, traveling around 1 million miles per hour, while the poles spew faster streams, traveling twice as fast at 2 million miles per hour. Stream Interaction Regions (SIRs) are created by interactions at boundaries between the fast and slow solar wind. Fast-moving streams tend to overtake slower streams that originate westward of them on the Sun, forming turbulent corotating interaction regions (CIRs) that produce shock waves and accelerated particles, not unlike those produced by CMEs.

    “For the first time, we observed low-energy particles from these CIRs near the orbit of Mercury,” Desai said. “We also compared the PSP data with data from STEREO, another solar energy probe. By measuring the full range of energetic populations and correlating the data with other measurements, we hope to get a clear picture of the origin and the processes that accelerate these particles. Our next step is to integrate the data into models to better understand the origin of SEPs and other materials. Parker Solar Probe will solve many puzzling scientific questions — and is guaranteed to generate new ones as well.”

    This research is described in the paper “Properties of Suprathermal-through-Energetic He Ions Associated with Stream interaction regions Observed over Parker Solar Probe’s First Two Orb­­its,” published February 3 in a special issue of The Astrophysical Journal Supplement Series devoted exclusively to the first science results from the Parker Solar Probe mission.

    PSP is part of NASA’s “Living With a Star” program to explore aspects of the Sun-Earth system that directly affect life and society. The Living With a Star flight program is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington.

    The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, manages the mission for NASA.

    APL designed and built the spacecraft and is operating it. The IS☉IS instrument suite has two instruments mounted to the spacecraft on an SwRI-designed and fabricated bracket. The EPI-Lo instrument measures the lower-energy particles. SwRI collaborated with the California Institute of Technology (Caltech) in the mechanical fabrication and analyses for the EPI-Hi instrument, which measures the higher-energy materials.

    Data from the IS☉IS instrument suite are processed by the IS☉IS Science Operations Center led by Prof. Nathan Schwadron at the University of New Hampshire. In addition to Princeton, JHU/APL, Caltech, SwRI and UNH, the ISʘIS team also includes scientists and engineers from NASA Goddard Space Flight Center, NASA Jet Propulsion Laboratory, the University of Delaware and the University of Arizona.

    NASA JPL


    U Delaware

    For more information, go to Heliophysics or contact Deb Schmid, +1 210 522 2254, Communications Department, Southwest Research Institute, PO Drawer 28510, San Antonio, TX 78228-0510.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    SwRI Campus

    Southwest Research Institute (SwRI) is an independent, nonprofit applied research and development organization. The staff of nearly 2,800 specializes in the creation and transfer of technology in engineering and the physical sciences. SwRI’s technical divisions offer a wide range of technical expertise and services in such areas as engine design and development, emissions certification testing, fuels and lubricants evaluation, chemistry, space science, nondestructive evaluation, automation, mechanical engineering, electronics, and more.

     
  • richardmitnick 12:47 pm on January 16, 2020 Permalink | Reply
    Tags: "Behind howls of solar wind quiet chirps reveal its origins", , , , , , NASA's Parker Solar Probe,   

    From JHU HUB: “Behind howls of solar wind, quiet chirps reveal its origins” 

    From JHU HUB

    1.15.20
    Jeremy Rehm

    1
    Image credit: NASA/Naval Research Laboratory/Parker Solar Probe

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker

    Scientists have studied the solar wind (pictured) for more than 60 years, but they’re still puzzled over some of its behaviors. The small chirps, squeaks, and rustles recorded by the Parker Solar Probe hint at the origin of this mysterious and ever-present wind.

    There’s a wind that emanates from the sun, and it blows not like a soft whistle but like a hurricane’s scream.

    Made of electrons, protons, and heavier ions, the solar wind courses through the solar system at roughly 1 million miles per hour, barreling over everything in its path. Yet through the wind’s roar, NASA’s Parker Solar Probe can hear small chirps, squeaks, and rustles that hint at the origins of this mysterious and ever-present wind. Now, the team at the Johns Hopkins Applied Physics Laboratory, which designed, built, and manages the Parker Solar Probe for NASA, is getting their first chance to hear those sounds, too.

    “We are looking at the young solar wind being born around the sun,” says Nour Raouafi, mission project scientist for the Parker Solar Probe. “And it’s completely different from what we see here near Earth.”


    Sounds of the Solar Wind from NASA’s Parker Solar Probe

    Scientists have studied the solar wind for more than 60 years, but they’re still puzzled over many of its behaviors. For example, while they know it comes from the sun’s million-degree outer atmosphere called the corona, the solar wind doesn’t slow down as it leaves the sun—it speeds up, and it has a sort of internal heater that keeps it from cooling as it zips through space. With growing concern about the solar wind’s ability to interfere with GPS satellites and disrupt power grids on Earth, it’s imperative to better understand it.

    Just 17 months since the probe’s launch and after three orbits around the sun, Parker Solar Probe has not disappointed in its mission.

    “We expected to make big discoveries because we’re going into uncharted territory,” Raouafi says. “What we’re actually seeing is beyond anything anybody imagined.”

    Researchers suspected that plasma waves within the solar wind could be responsible for some of the wind’s odd characteristics. Just as fluctuations in air pressure cause winds that force rolling waves on the ocean, fluctuations in electric and magnetic fields can cause waves that roll through clouds of electrons, protons, and other charged particles that make up the plasma racing away from the sun. Particles can ride these plasma waves much like the way a surfer rides an ocean wave, propelling them to higher speeds.

    “Plasma waves certainly play a part in heating and accelerating the particles,” Raouafi says. Scientists just don’t know how much of a part. That’s where Parker Solar Probe comes in.

    The spacecraft’s FIELDS instrument can eavesdrop on the electric and magnetic fluctuations caused by plasma waves. It can also “hear” when the waves and particles interact with one another, recording frequency and amplitude information about these plasma waves that scientists can then play as sound waves. And it results in some striking sounds.

    2
    Parker Solar Probe Diagram instrument FIELDS. NASA

    Take, for example, whistler-mode waves. These are caused by energetic electrons bursting out of the sun’s corona. These electrons follow magnetic field lines that stretch away from the sun out into the solar system’s farthest edge, spinning around them like they’re riding a carousel. When a plasma wave’s frequency matches how frequently those electrons are spin, they amplify one another. And it sounds like a scene out of Star Wars.

    “Some theories suggest that part of the solar wind’s acceleration is due to these escaping electrons,” says David Malaspina, a member of the FIELDS team and an assistant professor at the University of Colorado, Boulder, and the Laboratory for Atmospheric and Space Physics. He adds that the electrons could also be a critical clue to understanding one process that heats the solar wind.

    “We can use observations of these waves to work our way backward and probe the source of these electrons in the corona,” Malaspina says.

    Another example are dispersive waves, which quickly shift from one frequency to another as they move through the solar wind. These shifts create a sort of “chirp” that sounds like wind rushing over a microphone. They’re rare near the Earth, so researchers believed they were unimportant. But closer to the sun, scientists discovered, these waves are everywhere.

    “These waves haven’t been detected in the solar wind before, at least not in any large numbers,” Malaspina explains. “Nobody knows what causes these chirping waves or what they do to heat and accelerate the solar wind. That’s what we’re going to be determining. I think it’s incredibly exciting.”

    Raouafi commented that seeing all of this wave activity very close to the sun is why this mission is so critical. “We are seeing new, early behaviors of solar plasma we couldn’t observe here at Earth, and we’re seeing that the energy carried by the waves is being dissipated somewhere along the way, to heat and accelerate the plasma.”

    But it wasn’t just plasma waves that Parker Solar Probe heard. While barreling through a cloud of microscopic dust, the spacecraft’s instruments also captured a sound resembling old TV static. That static-like sound is actually hundreds of microscopic impacts happening every day: dust from asteroids torn apart by the sun’s gravity and heat and particles stripped away from comets strike the spacecraft at speeds close to a quarter of a million miles per hour. As Parker Solar Probe cruises through this dust cloud, the spacecraft doesn’t just crash into these particles—it obliterates them. Each grain’s atoms burst apart into electrons, protons, and other ions in a mini puff of plasma that the FIELDS instrument can “hear.”

    Each collision, however, also chips away a tiny bit of the spacecraft.

    “It was well understood that this would happen,” Malaspina says. “What was not understood was how much dust was going to be there.”

    APL engineers used models and remote observations to estimate how bad the dust situation might be well before the spacecraft launched. But in this uncharted territory, the number was bound to have some margin of error.

    James Kinnison, the Parker Solar Probe mission system engineer at APL, says this discrepancy in dust density is just one more reason why the probe’s proximity to the sun is so useful.

    “We protected almost everything from the dust,” Kinnison says. And although the dust is denser than expected, nothing right now points to dust impacts being a concern for the mission, he adds.

    Parker Solar Probe is scheduled to make another 21 orbits around the sun, using five flybys of Venus to propel itself increasingly closer to the star. Researchers will have the opportunity to better understand how these plasma waves change their behavior and to build a more complete evolutionary picture of the solar wind.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    About the Hub
    We’ve been doing some thinking — quite a bit, actually — about all the things that go on at Johns Hopkins. Discovering the glue that holds the universe together, for example. Or unraveling the mysteries of Alzheimer’s disease. Or studying butterflies in flight to fine-tune the construction of aerial surveillance robots. Heady stuff, and a lot of it.

    In fact, Johns Hopkins does so much, in so many places, that it’s hard to wrap your brain around it all. It’s too big, too disparate, too far-flung.

    We created the Hub to be the news center for all this diverse, decentralized activity, a place where you can see what’s new, what’s important, what Johns Hopkins is up to that’s worth sharing. It’s where smart people (like you) can learn about all the smart stuff going on here.

    At the Hub, you might read about cutting-edge cancer research or deep-trench diving vehicles or bionic arms. About the psychology of hoarders or the delicate work of restoring ancient manuscripts or the mad motor-skills brilliance of a guy who can solve a Rubik’s Cube in under eight seconds.

    There’s no telling what you’ll find here because there’s no way of knowing what Johns Hopkins will do next. But when it happens, this is where you’ll find it.

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
  • richardmitnick 3:47 pm on April 5, 2019 Permalink | Reply
    Tags: "And the Blobs Just Keep on Coming", , NASA's Parker Solar Probe, , Two German-NASA Helios spacecraft which launched in 1974 and 1976 to study the Sun   

    From NASA Goddard Space Flight Center: “And the Blobs Just Keep on Coming” 

    NASA Goddard Banner
    From NASA Goddard Space Flight Center

    April 4, 2019

    Lina Tran
    lina.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    When Simone Di Matteo first saw the patterns in his data, it seemed too good to be true. “It’s too perfect!” Di Matteo, a space physics Ph.D. student at the University of L’Aquila in Italy, recalled thinking. “It can’t be real.” And it wasn’t, he’d soon find out.

    Di Matteo was looking for long trains of massive blobs — like a lava lamp’s otherworldly bubbles, but anywhere from 50 to 500 times the size of Earth — in the solar wind. The solar wind, whose origins aren’t yet fully understood, is the stream of charged particles that blows constantly from the Sun. Earth’s magnetic field, called the magnetosphere, shields our planet from the brunt of its radiation. But when giant blobs of solar wind collide with the magnetosphere, they can trigger disturbances there that interfere with satellites and everyday communications signals.

    In his search, Di Matteo was re-examining archival data from the two German-NASA Helios spacecraft, which launched in 1974 and 1976 to study the Sun.

    NASA/DLR Helios spacecraft

    1
    Engineers inspect the Helios 2 spacecraft.
    Credits: NASA’s Goddard Space Flight Center

    But this was 45-year-old data he’d never worked with before. The flawless, wave-like patterns he initially found hinted that something was leading him astray.

    It wasn’t until uncovering and removing those false patterns that Di Matteo found exactly what he was looking for: dotted trails of blobs that oozed from the Sun every 90 minutes or so. The scientists published their findings in JGR Space Physics on Feb. 21, 2019. They think the blobs could shed light on the solar wind’s beginnings. Whatever process sends the solar wind out from the Sun must leave signatures on the blobs themselves.

    Making Way for New Science

    Di Matteo’s research was the start of a project NASA scientists undertook in anticipation of the first data from NASA’s Parker Solar Probe mission, which launched in 2018.

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker

    Over the next seven years, Parker will fly through unexplored territory, soaring as close as 4 million miles from the Sun. Before Parker, the Helios 2 satellite held the record for the closest approach to the Sun at 27 million miles, and scientists thought it might give them an idea of what to expect. “When a mission like Parker is going to see things no one has seen before, just a hint of what could be observed is really helpful,” Di Matteo said.

    The problem with studying the solar wind from Earth is distance. In the time it takes the solar wind to race across the 93 million miles between us and the Sun, important clues to the wind’s origins — like temperature and density — fade. “You’re constantly asking yourself, ‘How much of what I’m seeing here is because of evolution over four days in transit, and how much came straight from the Sun?’” said solar scientist Nicholeen Viall, who advised Di Matteo during his research at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Helios data — some of which was collected at just one-third the distance between the Sun and Earth — could help them begin to answer these questions.

    Modeling Blobs

    The first step was tracing Helios’ measurements of the blobs to their source on the Sun. “You can look at spacecraft data all you want, but if you can connect it back to where it came from on the Sun, it tells a more complete story,” said Samantha Wallace, one of the study collaborators and a physics Ph.D. student at the University of New Mexico in Albuquerque.

    Wallace used an advanced solar wind model to link magnetic maps of the solar surface to Helios’ observations, a tricky task since computer languages and data conventions have changed greatly since Helios’ days. Now, the researchers could see what sorts of regions on the Sun were likely to bud into blobs of solar wind.


    In the days before Parker Solar Probe, the record-breaking spacecraft for speed and closest approach to the Sun were the two Helios probes, launched in the mid-1970s. This visualization shows the orbits of Helios 1 and Helios 2, from an oblique view above the ecliptic plane.
    Credits: Tom Bridgman/NASA’s Scientific Visualization Studio

    Sifting the Evidence

    Then, Di Matteo searched the data for specific wave patterns. They expected conditions to alternate — hot and dense, then cold and tenuous — as individual blobs engulfed the spacecraft and moved on, in a long line.

    The picture-perfect patterns Di Matteo first found worried him. “That was a red flag,” Viall said. “The actual solar wind doesn’t have such precise, clean periodicities. Usually when you get such a precise frequency, it means some instrument effect is going on.” Maybe there was some element of the instrument design they weren’t considering, and it was imparting effects that had to be separated from true solar wind patterns.

    Di Matteo needed more information on the Helios instruments. But most researchers who worked on the mission have long since retired. He did what anyone else would do, and turned to the internet.

    Many Google searches and a weekend of online translators later, Di Matteo unearthed a German instruction manual that describes the instruments dedicated to the mission’s solar wind experiment. Decades ago, when Helios was merely a blueprint and before anyone ever launched a spacecraft to the Sun, scientists didn’t know how best to measure the solar wind. To prepare themselves for different scenarios, Di Matteo learned, they equipped the probes with two different instruments that would each measure certain solar wind properties in their own way. This was the culprit responsible for Di Matteo’s perfect waves: the spacecraft itself, as it alternated between two instruments.

    After they removed segments of data taken during routine instrument-switching, the researchers looked again for the blobs. This time, they found them. The team describes five instances that Helios happened to catch trains of blobs. While scientists have spotted these blobs from Earth before, this is the first time they’ve studied them this close to the Sun, and with this level of detail. They outline the first conclusive evidence that the blobs are hotter and denser than the typical solar wind.

    The Return of the Blobs

    Whether blob trains bubble in 90-minute intervals continuously or in spurts, and how much they vary between themselves, is still a mystery. “This is one of those studies that brought up more questions than we answered, but that’s perfect for Parker Solar Probe,” Viall said.

    Parker Solar Probe aims to study the Sun up close, seeking answers to basic questions about the solar wind. “This is going to be very helpful,” said Aleida Higginson, the mission’s deputy project scientist at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “If you want to even begin to understand things you’ve never seen before, you need to know what we’ve measured before and have a solid scientific interpretation for it.”

    Parker Solar Probe performs its second solar flyby on April 4, which brings it 15 million miles from the Sun — already cutting Helios 2’s record distance in half. The researchers are eager to see if blobs show up in Parker’s observations. Eventually, the spacecraft will get so close it could catch blobs right after they’ve formed, fresh out of the Sun.

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


    NASA/Goddard Campus

     
  • richardmitnick 10:43 am on February 20, 2019 Permalink | Reply
    Tags: "Solar Tadpole-Like Jets Seen With NASA’S IRIS Add New Clue to Age-Old Mystery", , , , , , , NASA's Parker Solar Probe,   

    From NASA Goddard Space Flight Center: “Solar Tadpole-Like Jets Seen With NASA’S IRIS Add New Clue to Age-Old Mystery” 

    NASA Goddard Banner
    From NASA Goddard Space Flight Center

    Feb. 19, 2019
    Mara Johnson-Groh
    mara.johnson-groh@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    NASA IRIS spacecraft

    Scientists have discovered tadpole-shaped jets coming out of regions with intense magnetic fields on the Sun. Unlike those living on Earth, these “tadpoles” — formally called pseudo-shocks — are made entirely of plasma, the electrically conducting material made of charged particles that account for an estimated 99 percent of the observable universe. The discovery adds a new clue to one of the longest-standing mysteries in astrophysics.

    1
    Anmated images from IRIS show the tadpole-shaped jets containing pseudo-shocks streaking out from the Sun.
    Credits: Abhishek Srivastava IIT (BHU)/Joy Ng, NASA’s Goddard Space Flight Center

    For 150 years scientists have been trying to figure out why the wispy upper atmosphere of the Sun — the corona — is over 200 times hotter than the solar surface. This region, which extends millions of miles, somehow becomes superheated and continually releases highly charged particles, which race across the solar system at supersonic speeds.

    When those particles encounter Earth, they have the potential to harm satellites and astronauts, disrupt telecommunications, and even interfere with power grids during particularly strong events. Understanding how the corona gets so hot can ultimately help us understand the fundamental physics behind what drives these disruptions.

    In recent years, scientists have largely debated two possible explanations for coronal heating: nanoflares and electromagnetic waves. The nanoflare theory proposes bomb-like explosions, which release energy into the solar atmosphere. Siblings to the larger solar flares, they are expected to occur when magnetic field lines explosively reconnect, releasing a surge of hot, charged particles. An alternative theory suggests a type of electromagnetic wave called Alfvén waves might push charged particles into the atmosphere like an ocean wave pushing a surfer. Scientists now think the corona may be heated by a combination of phenomenon like these, instead of a single one alone.

    The new discovery of pseudo-shocks adds another player to that debate. Particularly, it may contribute heat to the corona during specific times, namely when the Sun is active, such as during solar maximums — the most active part of the Sun’s 11-year cycle marked by an increase in sunspots, solar flares and coronal mass ejections.

    The discovery of the solar tadpoles was somewhat fortuitous. When recently analyzing data from NASA’s Interface Region Imaging Spectrograph, or IRIS, scientists noticed unique elongated jets emerging from sunspots ­— cool, magnetically-active regions on the Sun’s surface — and rising 3,000 miles up into the inner corona. The jets, with bulky heads and rarefied tails, looked to the scientists like tadpoles swimming up through the Sun’s layers.

    “We were looking for waves and plasma ejecta, but instead, we noticed these dynamical pseudo-shocks, like disconnected plasma jets, that are not like real shocks but highly energetic to fulfill Sun’s radiative losses,” said Abhishek Srivastava, scientist at the Indian Institute of Technology (BHU) in Varanasi, India, and lead author on the new paper in Nature Astronomy.

    Using computer simulations matching the events, they determined these pseudo-shocks could carry enough energy and plasma to heat the inner corona.

    2
    Animated computer simulation shows how the pseudo-shock is ejected and becomes disconnected from the plasma below (green). Credits: Abhishek Srivastava IIT (BHU)/Joy Ng, NASA’s Goddard Space Flight Center

    The scientists believe the pseudo-shocks are ejected by magnetic reconnection — an explosive tangling of magnetic field lines, which often occurs in and around sunspots. The pseudo-shocks have only been observed around the rims of sunspots so far, but scientists expect they’ll be found in other highly magnetized regions as well.

    3
    The tadpole-shaped pseudo-shocks, shown in dashed white box, are ejected from highly magnetized regions on the solar surface. Credits: Abhishek Srivastava IIT (BHU)/Joy Ng, NASA’s Goddard Space Flight Center

    Over the past five years, IRIS has kept an eye on the Sun in its 10,000-plus orbits around Earth. It’s one of several in NASA’s Sun-staring fleet that have continually observed the Sun over the past two decades. Together, they are working to resolve the debate over coronal heating and solve other mysteries the Sun keeps.

    “From the beginning, the IRIS science investigation has focused on combining high-resolution observations of the solar atmosphere with numerical simulations that capture essential physical processes,” said Bart De Pontieu research scientist at Lockheed Martin Solar & Astrophysics Laboratory in Palo Alto, California. “This paper is a nice illustration of how such a coordinated approach can lead to new physical insights into what drives the dynamics of the solar atmosphere.”

    The newest member in NASA’s heliophysics fleet, Parker Solar Probe, may be able to provide some additional clues to the coronal heating mystery.

    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker

    Launched in 2018, the spacecraft flies through the solar corona to trace how energy and heat move through the region and to explore what accelerates the solar wind as well as solar energetic particles. Looking at phenomena far above the region where pseudo-shocks are found, Parker Solar Probe’s investigation hopes to shed light on other heating mechanisms, like nanoflares and electromagnetic waves. This work will complement the research conducted with IRIS.

    “This new heating mechanism could be compared to the investigations that Parker Solar Probe will be doing,” said Aleida Higginson, deputy project scientist for Parker Solar Probe at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. “Together they could provide a comprehensive picture of coronal heating.”

    Related Links:

    Learn more about NASA’s IRIS Mission
    NASA’s Parker Solar Probe and the Curious Case of the Hot Corona
    Learn more about NASA’s Parker Solar Probe

    See the full article here.


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA’s Goddard Space Flight Center is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.


    NASA/Goddard Campus

     
  • richardmitnick 11:44 am on November 1, 2018 Permalink | Reply
    Tags: , , , , , , , NASA's Parker Solar Probe,   

    From JHU HUB: “The fastest, hottest mission under the sun” Parker Solar Probe 

    Johns Hopkins

    From JHU HUB

    1
    NASA Parker Solar Probe Plus named to honor Pioneering Physicist Eugene Parker.

    The Parker Solar Probe shatters records as it prepares for its first solar encounter.

    10.31.18
    Geoff Brown

    The Parker Solar Probe, designed, built, and operated by the Johns Hopkins Applied Physics Laboratory, now holds two operational records for a spacecraft and will continue to set new records during its seven-year mission to the sun.

    The Parker Solar Probe is now the closest spacecraft to the sun—it passed the current record of 26.55 million miles from the sun’s surface at 1:04 p.m. on Monday, as calculated by the Parker Solar Probe team. As the mission progresses, the spacecraft will make a final close approach of 3.83 million miles from the sun’s surface, expected in 2024.

    Also on Monday, Parker Solar Probe surpassed a speed of 153,454 miles per hour at 10:54 p.m., making it the fastest human-made object relative to the sun. The spacecraft will also accelerate over the course of the mission, achieving a top speed of about 430,000 miles per hour in 2024.

    The previous records for closest solar approach and speed were set by the German-American Helios 2 spacecraft in April 1976.

    “It’s been just 78 days since Parker Solar Probe launched, and we’ve now come closer to our star than any other spacecraft in history,” said project manager Andy Driesman of APL’s Space Exploration Sector. “It’s a proud moment for the team, though we remain focused on our first solar encounter, which begins [today].”

    The Parker Solar Probe team periodically measures the spacecraft’s precise speed and position using NASA’s Deep Space Network, or DSN. The DSN sends a signal to the spacecraft, which then retransmits it back, allowing the team to determine the spacecraft’s speed and position based on the timing and characteristics of the signal. The Parker Solar Probe’s speed and position were calculated using DSN measurements made up to Oct. 24, and the team used that information along with known orbital forces to calculate the spacecraft’s speed and position from that point on.

    NASA Deep Space Network

    NASA Deep Space Network


    NASA Deep Space Network dish, Goldstone, CA, USA


    NASA Canberra, AU, Deep Space Network

    The Parker Solar Probe will begin its first solar encounter today, continuing to fly closer and closer to the sun’s surface until it reaches its first perihelion—the name for the point where it is closest to the sun—at approximately 10:28 p.m. on Nov. 5, at a distance of about 15 million miles from the sun.

    The spacecraft will face brutal heat and radiation while providing unprecedented, close-up observations of a star and helping us understand phenomena that have puzzled scientists for decades. These observations will add key knowledge to our understanding of the sun, where changing conditions can propagate out into the solar system, affecting Earth and other planets.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings
    Please help promote STEM in your local schools.

    Stem Education Coalition

    About the Hub

    We’ve been doing some thinking — quite a bit, actually — about all the things that go on at Johns Hopkins. Discovering the glue that holds the universe together, for example. Or unraveling the mysteries of Alzheimer’s disease. Or studying butterflies in flight to fine-tune the construction of aerial surveillance robots. Heady stuff, and a lot of it.

    In fact, Johns Hopkins does so much, in so many places, that it’s hard to wrap your brain around it all. It’s too big, too disparate, too far-flung.

    We created the Hub to be the news center for all this diverse, decentralized activity, a place where you can see what’s new, what’s important, what Johns Hopkins is up to that’s worth sharing. It’s where smart people (like you) can learn about all the smart stuff going on here.

    At the Hub, you might read about cutting-edge cancer research or deep-trench diving vehicles or bionic arms. About the psychology of hoarders or the delicate work of restoring ancient manuscripts or the mad motor-skills brilliance of a guy who can solve a Rubik’s Cube in under eight seconds.

    There’s no telling what you’ll find here because there’s no way of knowing what Johns Hopkins will do next. But when it happens, this is where you’ll find it.

    Johns Hopkins Campus

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
  • richardmitnick 8:21 am on August 26, 2018 Permalink | Reply
    Tags: , NASA's Parker Solar Probe, , One photon emitted during the solar minimum had an energy as high as 467.7 GeV, , , Strange gamma rays from the sun may help decipher its magnetic fields, The high-energy light is more plentiful and weirder than anyone expected   

    From Science News: “Strange gamma rays from the sun may help decipher its magnetic fields” 

    From Science News

    August 24, 2018
    Lisa Grossman

    The high-energy light is more plentiful and weirder than anyone expected.

    1
    A TANGLED SKEIN The sun’s knotted magnetic fields, visualized here as white lines, scramble cosmic rays and may cause them to shoot energetic light called high-energy gamma rays toward Earth. Solar Dynamics Observatory/GSFC/NASA

    NASA/SDO

    The sleepy sun turns out to be a factory of extremely energetic light.

    Scientists have discovered that the sun puts out more of this light, called high-energy gamma rays, overall than predicted. But what’s really weird is that the rays with the highest energies appear when the star is supposed to be at its most sluggish, researchers report in an upcoming study in Physical Review Letters. The research is the first to examine these gamma rays over most of the solar cycle, a roughly 11-year period of waxing and waning solar activity.

    That newfound oddity is probably connected to the activity of the sun’s magnetic fields, the researchers say, and could lead to new insights about the mysterious environment.

    “The almost certain thing that’s going on here is the magnetic fields are much more powerful, much more variable, and much more weirdly shaped than we expect,” says astrophysicist John Beacom of the Ohio State University in Columbus.

    The sun’s high-energy gamma rays aren’t produced directly by the star. Instead, the light is triggered by cosmic rays — protons that zip through space with some of the highest energies known in nature — that smack into solar protons and produce high-energy gamma rays in the process (SN: 10/14/27, p. 7).

    All of those gamma rays would get lost inside the sun, if not for magnetic fields. Magnetic fields are known to take charged particles like cosmic rays and spin them around like a house in a tornado. Theorists have predicted that cosmic rays whose paths have been scrambled by the tangled mass of magnetic fields at the solar surface should send high-energy gamma rays shooting back out of the sun, where astronomers can see them.

    Beacom and colleagues, led by astrophysicist Tim Linden of Ohio State, sifted through data from NASA’s Fermi Gamma-ray Space Telescope from August 2008 to November 2017.

    NASA/Fermi LAT


    NASA/Fermi Gamma Ray Space Telescope

    The observations spanned a period of low solar activity in 2008 and 2009, a period of higher activity in 2013 and a decline in activity to the minimum of the next cycle, which started in 2018 (SN: 11/2/13, p. 22). The team tracked the number of solar gamma rays emitted per second, as well as their energies and where on the sun they came from.

    There were more high-energy gamma rays, above 50 billion electron volts, or GeV, than anyone predicted, the team reports. Weirder still, rays with energies above 100 GeV appeared only during the solar minimum, when the sun’s activity level was low. One photon emitted during the solar minimum had an energy as high as 467.7 GeV.

    Strangest of all, the sun seems to emit gamma rays from different parts of its surface at different times in its cycle. Because cosmic rays that hit the sun come in from all directions, you would expect the entire sun to light up in gamma rays uniformly. But Beacom’s team found that during the solar minimum, gamma rays came mainly from near the equator, and during the solar maximum, when the sun’s activity level was high, they clustered near the poles.

    “All of these things are way more weird than anyone had predicted,” Beacom says. “And that means the magnetic fields must be way more weird than anyone had thought.”
    ____________________________________________________
    The missing middle

    These plots show that the sun shot light called high-energy gamma rays from its middle during a period of low solar activity (from about August 2008 to the end of 2009, left), but not during a period of high activity (from 2010 until 2017, right). The gamma rays seem to migrate from the equator to the poles after 2010. Rays with less than 100 billion electron volts, or GeV, of energy are depicted as circles; those with 100 GeV or more are triangles. The bar graphs represent the number of gamma rays that came from different latitudes.

    3
    T. Linden et al/Physical Review Letters 2018
    ____________________________________________________

    Beacom and colleagues tried to connect the excess gamma rays to other solar behaviors that change with magnetic activity, like solar flares or sunspots (SN: 9/30/17, p. 6). “So far nothing has really held up to any sort of scrutiny,” says astrophysicist Annika Peter, also at Ohio State.

    High-energy gamma rays may offer a new way to probe the magnetic fields in the uppermost layer of the solar surface, called the photosphere. “You can’t see [the fields] with a telescope,” Beacom says. “But these [cosmic rays] are journeying there, and the gamma rays they send back are messengers of the terrible conditions there.”

    More observations are coming soon. NASA’s Parker Solar Probe, which launched on August 12, will take the first direct measurements of the magnetic field in the sun’s outer atmosphere, or corona (SN: 7/21/18, p. 12).

    154f8-sol_parkersolarprobe2_nasa


    NASA Parker Solar Probe Plus

    And as the sun enters the next solar minimum, the highest-energy gamma rays are starting to return. In February, Fermi caught its first gamma ray with an energy above 100 GeV since 2009.

    “There really is something strange afoot,” says solar physicist Craig DeForest of the Southwest Research Institute, who is based in Boulder, Colo., and was not involved in the work. “When there’s some new discovery, scientists don’t shout ‘Eureka!’ They go, ‘Hm, that’s funny. That can’t be right.’ This is a classic case of that.”

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
  • richardmitnick 2:31 pm on August 11, 2018 Permalink | Reply
    Tags: , , , , NASA's Parker Solar Probe, , United Launch Alliance Delta IV Heavy rocket   

    From NASA Spaceflight: “Parker Solar Probe” 

    NASA Spaceflight

    From NASA Spaceflight

    From
    Delta IV-Heavy scrubs first attempt to launch Parker Solar Probe
    written by Chris Gebhardt August 10, 2018

    Parker Solar Probe:

    The Parker Solar Probe began as an idea in the Outer Planet/Solar Probe program of NASA in the 1990s. The original mission concept, the Solar Orbiter, was canceled in 2003 as part of the George W. Bush Administration’s restructuring of NASA to focus more on research and development and address management shortcomings in the wake of the Space Shuttle Columbia accident.

    Six years later, the mission concept was resurrected as a “new mission start” in 2009 with an aim to launch a new solar probe in 2015. By 2012, as the mission moved into its design phase, the launch was pushed to 2018.

    Originally called the Solar Probe Plus, the mission was renamed on 31 May 2017 in honor of Dr. Eugene Parker. In so doing, NASA radically departed from its previous mission naming practices. All prior missions named after people were done so after their deaths in honor of their accomplishments and contributions to science.

    Breaking with this tradition, NASA renamed Solar Probe Plus the Parker Solar Probe after Dr. Parker – making him the first living person to have a NASA spacecraft named after him.

    1
    The mission patch for the Parker Solar Probe flagship science mission to “touch the Sun.” (Credit: NASA)

    A pioneering astrophysicist, Dr. Parker is best known for developing the theory of supersonic solar wind and correctly predicting the shape of the Heliospheric current sheet (or Parker spiral shape) of the solar magnetic field in the outer solar system. Furthermore, in 1987, Dr. Parker proposed that the solar corona was heated by a myriad of tiny nanoflares – solar flare-like brightenings that occur across the entirety of the Sun’s surface.

    Unlike other solar telescopes and missions, the Parker Solar Probe will venture where no probe has gone before – into the Sun’s corona. Mission planning calls for the probe to approach the Sun to within 6 million km (3.7 million miles) or just 0.04 AU – 8.5 solar radii.

    During its mission, Parker Solar will seek to answer three very important questions about the Sun:

    Why and how is the solar wind accelerated to supersonic speeds inside the corona?
    What is the mechanism that heats and accelerates particles in the corona?
    What is accelerating some particles, very few, to near the speed of light (creating highly energetic particles)?

    Answering that third question holds potentially great significance for our lives here on Earth and our quest to move beyond Earth and out into the solar system because these highly energetic particles are highly charged and can penetrate walls of spacecraft and be harmful for astronauts – like giving them a constant x-ray.

    These highly energetic particles can also wreak havoc with our electronics on Earth, in orbit, and in space. Therefore, part of Parker Solar’s mission is to help us better understand how the particles are accelerated/created in the corona – which in turn will help us better predict their occurrence and create improved plans for how to protect our technology and astronauts.

    Special heat shield and cooling system:

    Diving that close to the Sun, Parker Solar Probe will, according to NASA, “explore what is arguably the last and most important region of the solar system to be visited by a spacecraft and will finally answer top-priority science goals of the last five decades.”

    written by Chris Gebhardt August 10, 2018

    A mission nearly 60 years in the making is ready to launch on a historic flight to become the first spacecraft to “touch the surface of the Sun”. NASA’s Parker Solar Probe, named after Dr. Eugene Parker, will unlock many of the mysteries still held by our solar system’s star. The probe was set to launch atop at on Saturday but suffered from a scrub just minutes from launch due to an issue with a helium regulator. Another attempt will take place on Sunday, with the window opening at 03:31 Eastern.

    Parker Solar Probe:

    The Parker Solar Probe began as an idea in the Outer Planet/Solar Probe program of NASA in the 1990s. The original mission concept, the Solar Orbiter, was canceled in 2003 as part of the George W. Bush Administration’s restructuring of NASA to focus more on research and development and address management shortcomings in the wake of the Space Shuttle Columbia accident.

    Six years later, the mission concept was resurrected as a “new mission start” in 2009 with an aim to launch a new solar probe in 2015. By 2012, as the mission moved into its design phase, the launch was pushed to 2018.

    Originally called the Solar Probe Plus, the mission was renamed on 31 May 2017 in honor of Dr. Eugene Parker. In so doing, NASA radically departed from its previous mission naming practices. All prior missions named after people were done so after their deaths in honor of their accomplishments and contributions to science.

    Breaking with this tradition, NASA renamed Solar Probe Plus the Parker Solar Probe after Dr. Parker – making him the first living person to have a NASA spacecraft named after him.

    The mission patch for the Parker Solar Probe flagship science mission to “touch the Sun.” (Credit: NASA)

    A pioneering astrophysicist, Dr. Parker is best known for developing the theory of supersonic solar wind and correctly predicting the shape of the Heliospheric current sheet (or Parker spiral shape) of the solar magnetic field in the outer solar system. Furthermore, in 1987, Dr. Parker proposed that the solar corona was heated by a myriad of tiny nanoflares – solar flare-like brightenings that occur across the entirety of the Sun’s surface.

    Unlike other solar telescopes and missions, the Parker Solar Probe will venture where no probe has gone before – into the Sun’s corona. Mission planning calls for the probe to approach the Sun to within 6 million km (3.7 million miles) or just 0.04 AU – 8.5 solar radii.

    During its mission, Parker Solar will seek to answer three very important questions about the Sun:

    Why and how is the solar wind accelerated to supersonic speeds inside the corona?
    What is the mechanism that heats and accelerates particles in the corona?
    What is accelerating some particles, very few, to near the speed of light (creating highly energetic particles)?

    Answering that third question holds potentially great significance for our lives here on Earth and our quest to move beyond Earth and out into the solar system because these highly energetic particles are highly charged and can penetrate walls of spacecraft and be harmful for astronauts – like giving them a constant x-ray.

    These highly energetic particles can also wreak havoc with our electronics on Earth, in orbit, and in space. Therefore, part of Parker Solar’s mission is to help us better understand how the particles are accelerated/created in the corona – which in turn will help us better predict their occurrence and create improved plans for how to protect our technology and astronauts.

    Special heat shield and cooling system:

    Diving that close to the Sun, Parker Solar Probe will, according to NASA, “explore what is arguably the last and most important region of the solar system to be visited by a spacecraft and will finally answer top-priority science goals of the last five decades.”

    In order to survive the intense environment of the outer corona, an area in which the probe will experience solar intensity 520 times greater than Earth does, a specialized heat shield and cooling system were designed to protect the spacecraft and scientific instruments.

    The heat shield (or solar shadow-shield), which was installed for integrated vehicle testing in September 2017 at the Johns Hopkins Applied Physics Lab (APL), is made of reinforced carbon-carbon composite.

    Reinforced carbon-carbon is most widely and infamously known for its use on the Space Shuttle, as the nose cap and Wing Leading Edge elements of the Thermal Protection System on the five Orbiters – though it was initially developed for the nose cones of intercontinental ballistic missiles and is currently used in the brake systems for Formula One racing cars.

    For Parker Solar Probe, reinforced carbon-carbon will serve as the solar shadow-shield, which will block direct radiation from the Sun for the probe’s instrumentation and experiment packages and will keep temperatures behind the shield at a comfortable 85°F (29.4℃) while temperatures on the Sun-facing side of the shield will soar to 2,500°F (1,377℃) during closest approaches.

    Moreover, the mission’s proximity to the Sun also necessitated the development and use of a revolutionary cooling system to ensure the probe’s solar arrays continue to operate at peak efficiency in the extremely hostile conditions of the corona.

    2
    An artist’s depiction of the Parker Solar Probe as it dives toward the Sun for one of its close flybys into the corona. (Credit: NASA/APL)

    The arrays are designed with an upward bend at their outer edges. These edges will stick out beyond the solar shadow-shield during coronal passes to provide Parker Solar Probe with enough power for the spacecraft’s systems.

    “Our solar arrays are going to operate in an extreme environment that other missions have never operated in before,” said Mary Kae Lockwood, spacecraft system engineer for Parker Solar Probe at APL.

    While the surface of the solar shadow-shield will reach temperatures in excess of 2,500°F, the specially designed cooling system for the solar arrays will keep the arrays at a temperature of just 320°F or below.

    This will be the first-of-its-kind actively cooled solar array system and was developed by APL in partnership with United Technologies Aerospace Systems (which manufactured the cooling system) and SolAero Technologies (which produced the solar arrays).

    The cooling system itself is composed of a heated accumulator tank that will hold water (the coolant) during launch, two-speed pumps, and four radiators made of titanium tubes and aluminum fins just two hundredths of an inch thick.

    3
    Parker Solar Probe undergoing pre-flight checkouts. (Credit: NASA/APL)

    Water was chosen as the coolant because of the temperature range the system will encounter throughout the mission. “For the temperature range we required, and for the mass constraints, water was the solution,” said Lockwood.

    During and immediately after launch, the solar arrays and cooling system radiators will undergo wide temperature swings from 60°F (15°C) inside the payload fairing to -85°F through -220°F (-65°C to -140°C) once exposed to space before they can be warmed by the Sun. A pre-heated coolant tank will keep the coolant water from freezing.

    “One of the biggest challenges in testing this is those transitions from very cold to very hot in a short period of time,” Lockwood said. “But those tests, and other tests to show how the system works when under a fully-heated TPS, correlated quite well to our models.”

    Moreover, this testing and modeling showed the team that they needed to increase the thermal blanketing on the first two radiators that will be activated after launch in order to balance maximizing their capacity at the end of the mission with reducing the risk of the water freezing early in the mission.

    Getting Parker Solar Probe to the Sun – Calling the Delta IV Heavy:

    One might think that getting to the Sun is easier than getting to the outer planets and the farthest reaches of our solar system. But each actually include unique challenges that are put on full display with Parker Solar Probe.

    The challenge of getting to the Sun is the reverse of getting to the outer planets. When trying to reach the outer planets and reaches of the solar system, you seek to increase your velocity as you move through the solar system via gravitational assists – mainly from Jupiter.

    But Parker Solar Probe seeks to do the exact opposite, slowing itself down and giving energy (speed) to the inner planets – in this case, Venus – as it performs numerous flybys of the second rock from the Sun.

    So the questions then arise: if Parker Solar Probe needs to “go slow” to reach the Sun, why launch it at such a high velocity? And why is a high velocity bad for Parker Solar Probe when it’s going to become the fastest human-made object ever.

    The answer to the first question is the same as with all things space exploration: physics. A specific amount of energy (speed) is needed to escape Earth’s gravitational force. And that’s what the main part of the Delta IV Heavy has to do.

    But the Probe also has to overcome the speed at which Earth is moving around the Sun in its Orbit.

    3
    The Delta IV Heavy (Delta 9250H) is an expendable heavy-lift launch vehicle, the largest type of the Delta IV family and the world’s second highest-capacity rocket in operation, with a payload capacity half of SpaceX’s Falcon Heavy rocket. It is manufactured by United Launch Alliance and was first launched in 2004.

    Here, the specific mission parameters that call for Parker Solar Probe to make 24 close flybys of the Sun require a very specific trajectory and orbit. So to get to that orbit when Earth is moving around the Sun (and taking Parker with it), Parker Solar Probe actually has to start slowing down (relative to the Sun) during the powered phase of launch.

    This sounds contradictory to what we generally think of for launches, but part of the job of the third stage, in this case, is to start that slowing down process.

    During launch, the third stage’s velocity will increase because the speed relative to Earth is increasing. But, in fact, the velocity relative to the Sun is slowing down. This slow down will allow the Sun’s gravity to begin pulling Parker Solar inward toward Venus.

    Parker Solar Probe will then execute seven gravitational assist flybys of Venus so that it can perform progressively closer and closer flybys of the Sun’s surface. These progressively closer orbits are achieved by the probe’s interactions with Venus, which slow Parker Solar down (the slower you go, the closer you get to the Sun’s surface due to the Sun’s gravitational forces) and gives some of its energy to Venus in the process.

    The answer to the second question, why is such a high launch velocity bad for Parker Solar Probe’s operational mission, has to do with the parameters of the mission. Parker Solar is designed to perform multiple, close flybys of the Sun. If the probe were not to encounter Venus and fly directly toward the Sun at its full launch velocity, it would continuously gain speed as it approached the Sun and be flung off into a highly elliptical orbit that would not permit it to perform its 24 flybys within the spacecraft’s available lifetime.

    3
    Parker Solar Probe’s trajectory over the course of its planned 7-year mission. (NASA/APL)

    In short, it’s complicated. We have to launch Parker Solar at a high enough velocity to escape Earth’s gravitational field while simultaneously slowing the probe down so it doesn’t get flung out into an orbit that takes too long to complete for its scientific objectives – an event that would violate the mission’s entire purpose.

    So to do this, Parker Solar, while quite small and lightweight (weighing in at only 1,510 lbs, or 685 kg), needs a heavy-hitter launch vehicle. Enter the United Launch Alliance Delta IV Heavy.

    The mighty and majestic beast of the United Launch Alliance rocket family, the Delta IV Heavy will be tasked with sending Parker Solar on its merry way to the Sun. This will be the 10th flight of Delta IV Heavy as well as this rocket variant’s first mission to deliver an extremely important scientific payload to space.

    It will also be the lightest-weight known payload lifted to space by Delta IV Heavy. Of the non-classified Delta IV Heavy missions to date, the lightest-weight payload was Defense Support Program (DSP) -23 at 5,200kg.

    Assembly of this Delta IV Heavy rocket began in July and August 2017 with the arrival of the three Common Booster Cores that form the first stage of the Delta IV Heavy configuration. The Delta IV cores were all assembled in Decatur, Alabama, just west of Huntsville.

    After mating the three Common Booster Cores together, technicians inside the Horizontal Integration Facility at SLC-37B mated the Delta Cryogenic Second Stage (a modified version of which will serve as the SLS Block 1 rocket’s second stage) to the top of the three boosters in March 2018.

    Immediately thereafter, the Parker Solar Probe itself arrived in Titusville, Florida, at the Astrotech processing center on 3 April – where its final sequence of processing activities and checkouts for launch began.

    For the rocket, after a month of integrated checkouts in the integration facility, United Launch Alliance engineers rolled the assembled Delta IV Heavy the short way from its hanger to the launch mounts at SLC-37B on 16 April and erected the rocket on the pad the following day.

    A series of three Wet Dress Rehearsals were undertaken by the United Launch Alliance team for this particular Delta IV Heavy rocket in an attempt to ferret out any ground and vehicle issues that required attention and fixing prior to the scheduled launch.

    The number of Wet Dress Rehearsals (WDR) conducted for this mission was unusual – with two scheduled ahead of time and planned for because this is the first Delta IV rocket East Coast flight with the new common avionics suite.

    However, the first WDR was scrubbed due to lightning and the second resulted in issues that only permitted fueling of the three Common Booster Cores and not the second stage, so a third WDR was then scheduled.

    The third WDR was completed successfully, and a Mission Dress Rehearsal earlier this week and a final Flight Readiness Review all cleared the rocket and payload for launch.

    Parker Solar Probe and the Delta IV Heavy are slated to launch within a 65-minute launch window.

    After liftoff, Delta IV Heavy will pitch downrange and head due east over the Atlantic Ocean. Shortly after liftoff, the center core of the three Common Booster Cores (CBCs) of the first stage will throttle back to conserve propellant as the two side CBCs provide the brunt of the force lifting the rocket out of the dense lower atmosphere.

    At T+3 minutes 56 seconds into the flight, the two side cores will separate, and the center core will power back up to full thrust, burning until T+5 minutes 36 seconds – after which the center core will separate.

    The Delta Cryogenic Second Stage (DCSS) will then ignite for the first of its two burns. The first of these burns will end at T+10 minutes 37 seconds – at which point Parker Solar will be in its initial parking orbit.

    The DCSS will reignite for a second burn at T+22 minutes 25 seconds. This burn will last for about 14 minutes.

    5
    The Star 48 third stage fires to send the Parker Solar Probe into its correct orbit toward Venus. (Credit: NASA)

    After the second DCSS engine cutoff, the 2nd and 3rd stages will separate – with the Northrop Grumman-built third stage, the STAR 48BV. This is a solid propellant stage that will produce 17,490 lbs of thrust for just 84 seconds. But in that 84 seconds, the third stage will impart two-thirds of the total velocity of the launch phase.

    (Of note, this is not the only part of the Delta IV Heavy built by Northrop Grumman. The first stage engine nozzles, pressurization tanks, payload fairing, and most of the white areas on the rocket are all built by Northrop Grumman.)

    Once that small duration burn is complete, Parker Solar Probe will separate from the third stage and be on its inward dive toward Venus.

    Assuming launch on 11 August, Parker Solar will encounter Venus for the first of seven flybys on 2 October 2018. It will then perform its first close flyby of the Sun – perihelion – on 5 November 2018.

    Overall, Parker Solar Probe has a launch window that extends to 23 August 2018 due to the need to intercept Venus. If, for some reason, the mission has not launched by then, launch will have to wait until May 2019 for the next Earth-Venus alignment.

    See the full article here .

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    Please help promote STEM in your local schools.

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    NASASpaceFlight.com, now in its eighth year of operations, is already the leading online news resource for everyone interested in space flight specific news, supplying our readership with the latest news, around the clock, with editors covering all the leading space faring nations.

    Breaking more exclusive space flight related news stories than any other site in its field, NASASpaceFlight.com is dedicated to expanding the public’s awareness and respect for the space flight industry, which in turn is reflected in the many thousands of space industry visitors to the site, ranging from NASA to Lockheed Martin, Boeing, United Space Alliance and commercial space flight arena.

    With a monthly readership of 500,000 visitors and growing, the site’s expansion has already seen articles being referenced and linked by major news networks such as MSNBC, CBS, The New York Times, Popular Science, but to name a few.

     
  • richardmitnick 10:03 am on August 7, 2018 Permalink | Reply
    Tags: , , , , , , NASA's Parker Solar Probe,   

    From JHU HUB: “Can the Parker Solar Probe take the heat?” 

    Johns Hopkins

    From JHU HUB

    8.6.18
    By Tracy Vogel

    1
    NASA JHUAPL Parker Solar Probe approaches the sun.

    Researchers at the Applied Physics Lab develop a shield strong enough to protect the spacecraft’s sensitive instruments during its mission to “touch” the sun.

    The star of the show is a dark gray block, about the size of a textbook, and several inches thick. As an audience of reporters watches, an engineer runs a flaming blowtorch over the block until its face heats to a red glow.

    “You want to take a touch of the back surface?” she invites a NASA T-shirt-clad volunteer.

    The volunteer reaches tentatively out to the back, first with one finger, and then with her whole hand.

    “How does it feel?”

    “Lukewarm,” the volunteer responds. “Not even—normal.”


    Video: NASA Goddard

    The demonstration, dubbed “Blowtorch vs. Heat Shield” on YouTube, represents the culmination of years of research, trial and error, and painstaking analysis by engineers at the Johns Hopkins University Applied Physics Laboratory to solve what they call the “thermal problem” of the Parker Solar Probe, a spacecraft that will travel within 4 million miles of the surface of the sun.

    The “thermal problem” is a gentle way of referring to the complications of performing this record-breaking dive directly into our star’s outer atmosphere, or corona. While the Parker Solar Probe orbits the star and records data with its onboard instruments, a thermal protection system, or TPS, will shield the spacecraft from the heat. Combined with a water-powered cooling system, the TPS will keep the majority of the spacecraft’s instruments at about 85 degrees Fahrenheit—a nice summer day—while the TPS itself endures a temperature of 2500 degrees Fahrenheit.

    Without the TPS, there’s no probe.

    “This was the technology that enabled us to do this mission—to enable it to fly,” says Elisabeth Abel, TPS thermal lead. “It’s going to be incredibly exciting to see something you put a lot of energy and hard work into, to see it actually fly. It’s going to be a big day.”

    The “thermal problem” is a gentle way of referring to the complications of performing this record-breaking dive directly into our star’s outer atmosphere, or corona. While the Parker Solar Probe orbits the star and records data with its onboard instruments, a thermal protection system, or TPS, will shield the spacecraft from the heat. Combined with a water-powered cooling system, the TPS will keep the majority of the spacecraft’s instruments at about 85 degrees Fahrenheit—a nice summer day—while the TPS itself endures a temperature of 2500 degrees Fahrenheit.

    The Parker Solar Probe is expected to launch from Kennedy Space Center in Cape Canaveral, Florida, this month—its launch window opens Saturday and runs through Aug. 23. During its seven-year mission, it’ll explore some of the sun’s greatest mysteries: Why is the solar wind a breeze closer to the sun but supersonic torrent farther away? Why is the corona itself millions of degrees hotter than the surface of the sun? What are the mechanisms behind the astoundingly fast-moving solar energetic particles that can interfere with spacecraft, disrupt communications on Earth, and endanger astronauts?

    The launch will conclude 60 years of planning and effort, and more than a decade spent creating the heat shield that deflects the worst of the sun’s energy.

    The front and back faces of the heat shield are made of sheets of carbon-carbon, a lightweight material with superior mechanical properties especially suited for high temperatures. At less than a tenth of an inch thick, the two carbon-carbon sheets are thin enough to bend, even if they were laid on top of each other. Between them is about 4.5 inches of carbon foam, typically used in the medical industry for bone replacement. This sandwich design stiffens everything up—like corrugated cardboard—while allowing the 8-foot heat shield to weigh in at only about 160 pounds.

    The foam also performs the heat shield’s most essential structural functions. Carbon itself conducts heat, but carbon foam is 97 percent air. In addition to cutting the weight of the spacecraft to help it get into orbit, the foam structure means there’s just not that much material for heat to travel through. The heat shield will be 2500 degrees Fahrenheit on the side facing the sun, but only 600 degrees Fahrenheit at the back.

    The foam wasn’t easy to test. It’s extremely fragile, and there was another problem.

    “When you get it hot, it can combust,” Abel says.

    Combustion isn’t an issue in a vacuum (like in space), but leftover air in test chambers would cause the foam to char. So the engineers built their own vacuum chamber at Oak Ridge National Laboratory, where a high-temperature plasma-arc lamp facility could heat the material to the incredible temperatures the heat shield would endure.

    3
    Image credit: Greg Stanley / Office of Communications

    But all of the carbon foam’s impressive heat-dispersing properties weren’t enough to keep the spacecraft at its required temperature. Because there’s no air in space to provide cooling, the only way for material to expel heat is to scatter light and eject heat in the form of photons. For that, another layer of protection was necessary: a white coating that would reflect heat and light.

    For that, APL turned to the Advanced Technology Laboratory in Johns Hopkins University’s Whiting School of Engineering, where a fortunate coincidence had led to the assembly of a heat shield–coating dream team: experts in high-temperature ceramics, chemistry, and plasma spray coatings.

    After extensive engineering and testing, the team settled on a coating based on bright white aluminum oxide. But that coating could react with the carbon of the heat shield in high temperatures and turn gray, so the engineers added a layer of tungsten, thinner than a strand of hair, between the heat shield and the coating to stop the two from interacting. They added nanoscale dopants to make the coating whiter and to inhibit the expansion of aluminum oxide grains when exposed to heat.

    Then the engineers had to determine how best to create and apply the coating.

    “The whole thing was struggling to find a ceramic coating that both reflects light and emits the heat,” says Dennis Nagle, principal research engineer at the Center for Systems Science and Engineering.

    Typically when working with enamel, Nagle says, a hard, nonporous coating is preferred—one that’ll crack when hit with a hammer. But under the temperatures faced by the Parker Solar Probe, a smooth coating would shatter like a window hit with a rock. Instead the goal was a uniformly porous coating that would withstand extreme environments. When cracks start in a porous coating, they’ll stop when they hit a pore. The coating was made of several rough, grainy layers—enough that one set of ceramic grains would reflect light that another layer misses.

    “I always tell people it works because it’s a lousy coating,” jokes Nagle. “If you want to make a good coating, it’ll fail.”

    After the Parker Solar Probe launches, it will spin repeatedly around Venus in a gradually narrowing orbit that will take it closer and closer to the sun. Scientists are eagerly awaiting the flood of new data from the probe’s instruments, but those who helped make the heat shield a reality say the thrill will be in seeing that final dip into the sun’s atmosphere, seven times closer than any previous spacecraft, the car-sized probe and its precious cargo defended from the sun’s might by their work.

    But seven years is a long time to wait for a final test of success, so the launch will have to do for now.

    “This was highly challenging,” says Dajie Zhang, a senior staff scientist in APL’s Research and Exploratory Development Department who worked on the TPS coating. “It makes me feel much better coming into work every day. The solar probe’s success showed me I can do it, and our team can do it.”

    See the full article here .


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    About the Hub

    We’ve been doing some thinking — quite a bit, actually — about all the things that go on at Johns Hopkins. Discovering the glue that holds the universe together, for example. Or unraveling the mysteries of Alzheimer’s disease. Or studying butterflies in flight to fine-tune the construction of aerial surveillance robots. Heady stuff, and a lot of it.

    In fact, Johns Hopkins does so much, in so many places, that it’s hard to wrap your brain around it all. It’s too big, too disparate, too far-flung.

    We created the Hub to be the news center for all this diverse, decentralized activity, a place where you can see what’s new, what’s important, what Johns Hopkins is up to that’s worth sharing. It’s where smart people (like you) can learn about all the smart stuff going on here.

    At the Hub, you might read about cutting-edge cancer research or deep-trench diving vehicles or bionic arms. About the psychology of hoarders or the delicate work of restoring ancient manuscripts or the mad motor-skills brilliance of a guy who can solve a Rubik’s Cube in under eight seconds.

    There’s no telling what you’ll find here because there’s no way of knowing what Johns Hopkins will do next. But when it happens, this is where you’ll find it.

    Johns Hopkins Campus

    The Johns Hopkins University opened in 1876, with the inauguration of its first president, Daniel Coit Gilman. “What are we aiming at?” Gilman asked in his installation address. “The encouragement of research … and the advancement of individual scholars, who by their excellence will advance the sciences they pursue, and the society where they dwell.”

    The mission laid out by Gilman remains the university’s mission today, summed up in a simple but powerful restatement of Gilman’s own words: “Knowledge for the world.”

    What Gilman created was a research university, dedicated to advancing both students’ knowledge and the state of human knowledge through research and scholarship. Gilman believed that teaching and research are interdependent, that success in one depends on success in the other. A modern university, he believed, must do both well. The realization of Gilman’s philosophy at Johns Hopkins, and at other institutions that later attracted Johns Hopkins-trained scholars, revolutionized higher education in America, leading to the research university system as it exists today.

     
  • richardmitnick 9:46 am on July 19, 2018 Permalink | Reply
    Tags: , NASA's Parker Solar Probe, Occulting disc, , , ,   

    From Southwest Research Institute via Science Alert: “Never-Before-Seen Structures Have Been Detected in Our Sun’s Corona” 

    SwRI bloc

    From Southwest Research Institute

    via

    ScienceAlert

    Science Alert

    19 JUL 2018
    MICHELLE STARR

    1
    DeForest et al./The Astrophysical Journal

    Using longer exposures and sophisticated processing techniques, scientists have taken extraordinarily high-fidelity pictures of the Sun’s outer atmosphere – what we call the corona – and discovered fine details that have never been detected before.

    The Sun is a complex object, and with the soon-to-be-launched Parker Solar Probe we’re on the verge of learning so much more about it.

    NASA Parker Solar Probe Plus

    But there’s still a lot we can do with our current technology, as scientists from the Southwest Research Institute (SwRI) have just demonstrated.

    The team used the COR-2 coronagraph instrument on NASA’s Solar and Terrestrial Relations Observatory-A (STEREO-A) to study details in the Sun’s outer atmosphere.

    NASA/STEREO spacecraft

    This instrument takes images of the atmosphere by using what is known as an occulting disc – a disc placed in front of the lens that blocks out the actual Sun from the image, and therefore the light that would overwhelm the fine details in the plasma of the Sun’s atmosphere.

    The corona is extremely hot, much hotter than the inner photosphere’s 5,800 Kelvin, coming in at between 1 and 3 million Kelvin. It’s also the source of solar wind – the constant stream of charged particles that flows out from the Sun in all directions.

    When measurements of the solar wind are taken near Earth, the magnetic fields embedded therein are complex and interwoven, but it’s unclear when this turbulence occurs.

    “In deep space, the solar wind is turbulent and gusty,” says solar physicist Craig DeForest of the SwRI.

    “But how did it get that way? Did it leave the Sun smooth, and become turbulent as it crossed the solar system, or are the gusts telling us about the Sun itself?”

    If the turbulence was occurring at the source of the solar wind – the Sun – then we should have been able to see complex structures in the corona as the cause of it, but previous observations showed no such structures.

    Instead, they showed the corona as a smooth, laminar structure. Except, as it turns out, that wasn’t the case. The structures were there, but we hadn’t been able to obtain a high enough image resolution to see them.

    2
    NASA/SwRI/STEREO

    “Using new techniques to improve image fidelity, we realised that the corona is not smooth, but structured and dynamic,” DeForest explains. “Every structure that we thought we understood turns out to be made of smaller ones, and to be more dynamic than we thought.”

    To obtain the images, the research team ran a special three-day campaign wherein the instrument took more frequent and longer-exposure images than it usually does, allowing more time for light from faint sources to be detected by the coronagraph. But that was only part of the process.

    Although the occulting disc does a great job at filtering out the bright light from the Sun, there’s still a great deal of noise in the resulting images, both from the surrounding space and the instrument.

    Obviously, since STEREO-A is in space, altering the hardware isn’t an option, so DeForest and his team worked out a technique for identifying and removing that noise, vastly improving the data’s signal-to-noise ratio.

    They developed new filtering algorithms to separate the corona from noise, and adjust brightness. And, perhaps more challengingly, correct for the blur caused by the motion of the solar wind.

    They discovered that the coronal loops known as streamers – which can erupt into the coronal mass ejections that send plasma and particles shooting out into space – are not one single structure.

    “There is no such thing as a single streamer,” DeForest said. “The streamers themselves are composed of myriad fine strands that, together, average to produce a brighter feature.”

    They also found there’s no such thing as the Alfvén surface – a theoretical, sheet-like boundary where the solar wind starts moving forward faster than waves can travel backwards through it, and it disconnects from the Sun, moving beyond its influence.

    Instead, DeForest said, “There’s a wide ‘no-man’s land’ or ‘Alfvén zone’ where the solar wind gradually disconnects from the Sun, rather than a single clear boundary.”

    But the research also presented a new mystery to probe, as well. At a distance of about 10 solar radii the solar wind suddenly changes character. But it returns to normal farther out from the Sun, indicating that there’s some interesting physics happening at 10 solar radii.

    Figuring out what that is may require some help from Parker, for which this research is key. Parker is due to launch in August.

    Meanwhile, the team’s research has been published in The Astrophysical Journal.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    SwRI Campus

    Southwest Research Institute (SwRI) is an independent, nonprofit applied research and development organization. The staff of nearly 2,800 specializes in the creation and transfer of technology in engineering and the physical sciences. SwRI’s technical divisions offer a wide range of technical expertise and services in such areas as engine design and development, emissions certification testing, fuels and lubricants evaluation, chemistry, space science, nondestructive evaluation, automation, mechanical engineering, electronics, and more.

     
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