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  • richardmitnick 4:01 pm on January 6, 2017 Permalink | Reply
    Tags: HD 172555, Hubble Detects 'Exocomets' Taking the Plunge into a Young Star, , NASA Goddard   

    From Hubble: “Hubble Detects ‘Exocomets’ Taking the Plunge into a Young Star” 

    NASA Hubble Banner

    NASA/ESA Hubble Telescope

    NASA/ESA Hubble Telescope

    Jan 6, 2017
    Donna Weaver
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4493
    dweaver@stsci.edu

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland
    410-338-4514
    villard@stsci.edu

    Carol Grady
    Eureka Scientific Inc., Oakland, California,
    and Goddard Space Flight Center, Greenbelt, Maryland
    301-286-3748
    carol.a.grady@nasa.gov

    1

    Interstellar forecast for a nearby star: Raining comets! NASA’s Hubble Space Telescope has discovered comets plunging into the star HD 172555, which is a youthful 23 million years old and resides 95 light-years from Earth.

    The exocomets — comets outside our solar system — were not directly seen around the star, but their presence was inferred by detecting gas that is likely the vaporized remnants of their icy nuclei.

    HD 172555 represents the third extrasolar system where astronomers have detected doomed, wayward comets. All of these systems are young, under 40 million years old.

    The presence of these doomed comets provides circumstantial evidence for “gravitational stirring” by an unseen Jupiter-size planet, where comets deflected by the massive object’s gravity are catapulted into the star. These events also provide new insights into the past and present activity of comets in our solar system. It’s a mechanism where infalling comets could have transported water to Earth and the other inner planets of our solar system.

    Astronomers have found similar plunges in our own solar system. Sun-grazing comets routinely fall into our sun. “Seeing these sun-grazing comets in our solar system and in three extrasolar systems means that this activity may be common in young star systems,” said study leader Carol Grady of Eureka Scientific Inc., in Oakland, California, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This activity at its peak represents a star’s active teenage years. Watching these events gives us insight into what probably went on in the early days of our solar system, when comets were pelting the inner solar system bodies, including Earth. In fact, these star-grazing comets may make life possible, because they carry water and other life-forming elements, such as carbon, to terrestrial planets.”

    Grady will present her team’s results Jan. 6 at the winter meeting of the American Astronomical Society in Grapevine, Texas.

    The star is part of the Beta Pictoris Moving Group, a collection of stars born from the same stellar nursery.

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    Beta Pictoris Moving Group. http://astronomyonline.org/Exoplanets/ExoplanetDynamics.asp#I4

    It is the second group member found to harbor such comets. Beta Pictoris, the group’s namesake, also is feasting on exocomets travelling too close. A young gas-giant planet has been observed in that star’s vast debris disk.

    The Beta Pictoris Moving Group is important to study because it is the closest collection of young stars to Earth. At least 37.5 percent of the more massive stars in the group either have a directly imaged planet, such as 51 Eridani b in the 51 Eridani system, or infalling star-grazing bodies, or, in the case of Beta Pictoris, both types of objects. The grouping is around the age where it should be building terrestrial planets, Grady said.

    A team of French astronomers first discovered exocomets transiting HD 172555 in archival data gathered between 2004 and 2011 by the European Southern Observatory’s HARPS (High Accuracy Radial velocity Planet Searcher) spectrograph. A spectrograph divides light into its component colors, allowing astronomers to detect an object’s chemical makeup. The HARPS spectrograph detected the chemical fingerprints of calcium imprinted in the starlight, evidence that comet-like objects were falling into the star.

    As a follow-up to that discovery, Grady’s team used Hubble’s Space Telescope Imaging Spectrograph (STIS) and the Cosmic Origins Spectrograph (COS) in 2015 to conduct a spectrographic analysis in ultraviolet light, which allows Hubble to identify the signature of certain elements. Hubble made two observations, separated by six days.

    Hubble detected silicon and carbon gas in the starlight. The gas was moving at about 360,000 miles per hour across the face of the star. The most likely explanation for the speedy gas is that Hubble is seeing material from comet-like objects that broke apart after streaking across the star’s disk.

    The gaseous debris from the disintegrating comets is vastly dispersed in front of the star. “As transiting features go, this vaporized material is easy to see because it contains very large structures,” Grady said. “This is in marked contrast to trying to find a small, transiting exoplanet, where you’re looking for tiny dips in the star’s light.”

    Hubble gleaned this information because the HD 172555 debris disk surrounding the star is viewed close to edge-on through the disk, giving the telescope a clear view of comet activity.

    Grady’s team hopes to use STIS again in follow-up observations to look for oxygen and hydrogen, which would confirm the identity of the disintegrating objects as comets.

    “Hubble shows that these star-grazers look and move like comets, but until we determine their composition, we cannot confirm they are comets,” Grady said. “We need additional data to establish whether our star-grazers are icy like comets or more rocky like asteroids.”

    See the full article here .

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 9:57 am on January 5, 2017 Permalink | Reply
    Tags: , , , , NASA Goddard, ,   

    From NASA: “NASA Selects Two Missions to Explore the Early Solar System” 

    NASA image
    NASA

    Jan. 4, 2017
    Dwayne Brown
    dwayne.c.brown@nasa.gov
    Headquarters, Washington
    202-358-1726

    Laurie Cantillo
    laura.l.cantillo@nasa.gov
    Headquarters, Washington
    202-358-1077

    1
    (Left) An artist’s conception of the Lucy spacecraft flying by the Trojan Eurybates – one of the six diverse and scientifically important Trojans to be studied. Trojans are fossils of planet formation and so will supply important clues to the earliest history of the solar system. (Right) Psyche, the first mission to the metal world 16 Psyche will map features, structure, composition, and magnetic field, and examine a landscape unlike anything explored before. Psyche will teach us about the hidden cores of the Earth, Mars, Mercury and Venus.
    Credits: SwRI and SSL/Peter Rubin

    NASA has selected two missions that have the potential to open new windows on one of the earliest eras in the history of our solar system – a time less than 10 million years after the birth of our sun. The missions, known as Lucy and Psyche, were chosen from five finalists and will proceed to mission formulation, with the goal of launching in 2021 and 2023, respectively.

    “Lucy will visit a target-rich environment of Jupiter’s mysterious Trojan asteroids, while Psyche will study a unique metal asteroid that’s never been visited before,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “This is what Discovery Program missions are all about – boldly going to places we’ve never been to enable groundbreaking science.”


    Access mp4 video here .

    Lucy, a robotic spacecraft, is scheduled to launch in October 2021. It’s slated to arrive at its first destination, a main belt asteroid, in 2025. From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter’s gravity in two swarms that share the planet’s orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter’s current orbit.

    “This is a unique opportunity,” said Harold F. Levison, principal investigator of the Lucy mission from the Southwest Research Institute in Boulder, Colorado. “Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins.”

    Lucy will build on the success of NASA’s New Horizons mission to Pluto and the Kuiper Belt, using newer versions of the RALPH and LORRI science instruments that helped enable the mission’s achievements.

    NASA/New Horizons spacecraft
    NASA/New Horizons spacecraft

    Kuiper Belt. Minor Planet Center
    Kuiper Belt. Minor Planet Center

    Several members of the Lucy mission team also are veterans of the New Horizons mission. Lucy also will build on the success of the OSIRIS-REx mission to asteroid Bennu, with the OTES instrument and several members of the OSIRIS-REx team.

    NASA OSIRIS-REx Spacecraft
    NASA OSIRIS-REx Spacecraft

    The Psyche mission will explore one of the most intriguing targets in the main asteroid belt – a giant metal asteroid, known as 16 Psyche, about three times farther away from the sun than is the Earth. This asteroid measures about 130 miles (210 kilometers) in diameter and, unlike most other asteroids that are rocky or icy bodies, is thought to be comprised mostly of metallic iron and nickel, similar to Earth’s core. Scientists wonder whether Psyche could be an exposed core of an early planet that could have been as large as Mars, but which lost its rocky outer layers due to a number of violent collisions billions of years ago.

    The mission will help scientists understand how planets and other bodies separated into their layers – including cores, mantles and crusts – early in their histories.

    “This is an opportunity to explore a new type of world – not one of rock or ice, but of metal,” said Psyche Principal Investigator Lindy Elkins-Tanton of Arizona State University in Tempe. “16 Psyche is the only known object of its kind in the solar system, and this is the only way humans will ever visit a core. We learn about inner space by visiting outer space.”

    Psyche, also a robotic mission, is targeted to launch in October of 2023, arriving at the asteroid in 2030, following an Earth gravity assist spacecraft maneuver in 2024 and a Mars flyby in 2025.

    In addition to selecting the Lucy and Psyche missions for formulation, the agency will extend funding for the Near Earth Object Camera (NEOCam) project for an additional year. The NEOCam space telescope is designed to survey regions of space closest to Earth’s orbit, where potentially hazardous asteroids may be found.

    “These are true missions of discovery that integrate into NASA’s larger strategy of investigating how the solar system formed and evolved,” said NASA’s Planetary Science Director Jim Green. “We’ve explored terrestrial planets, gas giants, and a range of other bodies orbiting the sun. Lucy will observe primitive remnants from farther out in the solar system, while Psyche will directly observe the interior of a planetary body. These additional pieces of the puzzle will help us understand how the sun and its family of planets formed, changed over time, and became places where life could develop and be sustained – and what the future may hold.”

    Discovery Program class missions like these are relatively low-cost, their development capped at about $450 million. They are managed for NASA’s Planetary Science Division by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama. The missions are designed and led by a principal investigator, who assembles a team of scientists and engineers, to address key science questions about the solar system.

    The Discovery Program portfolio includes 12 prior selections such as the MESSENGER mission to study Mercury, the Dawn mission to explore asteroids Vesta and Ceres, and the InSight Mars lander, scheduled to launch in May 2018.

    NASA’s other missions to asteroids began with the NEAR orbiter of asteroid Eros, which arrived in 2000, and continues with Dawn, which orbited Vesta and now is in an extended mission phase at Ceres. The OSIRIS-REx mission, which launched on Sept. 8, 2016, is speeding toward a 2018 rendezvous with the asteroid Bennu, and will deliver a sample back to Earth in 2023. Each mission focuses on a different aspect of asteroid science to give scientists the broader picture of solar system formation and evolution.

    Read more about NASA’s Discovery Program and missions at:

    https://discovery.nasa.gov/missions.cfml

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

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

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

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

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

     
  • richardmitnick 4:29 pm on January 4, 2017 Permalink | Reply
    Tags: , , NASA Goddard, Sophie Nowicki,   

    From Goddard: Women in STEM – “Sophie Nowicki – Hot on Glaciology “ 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Jan. 4, 2017
    Elizabeth M. Jarrell
    NASA Goddard Space Flight Center

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    Sophie Nowicki. Credits: NASA/W. Hrybyk.

    Name: Sophie Nowicki
    Formal Job Classification: Physical Scientist
    Organization: Code 615, Cryospheric Sciences Laboratory, Earth Sciences Division, Sciences and Exploration Directorate

    What do you do and what is most interesting about your role here at Goddard? How do you help support Goddard’s mission?

    I’m a glaciologist and I study the big ice sheets of Greenland and Antarctica. I want to understand how in the future they will evolve and contribute to sea level change. I use my models together with NASA’s climate models to make global projections of future sea levels.

    I use data collected by NASA in my models to check how the models compare to the real world. For example, I use data from airborne observations from Operation IceBridge and data from Ice, Cloud, and land Elevation (ICESat) satellite and the Gravity Recovery and Climate Experiment (GRACE) satellite.

    NASA/Grace
    “NASA/Grace

    Operation IceBridge is an airborne campaign that takes lots of different measurements, including the bedrock and the ice elevation in and around Greenland and Antarctica. ICESat was a satellite that measured ice sheet elevation of the Greenland and Antarctic. GRACE is a satellite that measures the mass change of the Greenland and Antarctic ice sheets.

    How do use your numerical models in conjunction with the climate models?

    Our numerical models add a new capability to NASA’s existing climate models because the climate models now include interactive ice sheets. We also modified the snow models that sit between the atmosphere and the ice sheets. This allows us to better capture the surface conditions over the ice sheets such as the snow melting identified by the satellites or the surface temperature over the ice sheets.

    We work with a tremendous amount of data. We assimilate all this data and make projections using NASA’s two supercomputers. One is at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the other is at NASA’s Goddard Institute for Space Studies (GISS) in New York City.

    Do you work both at Goddard and at GISS?

    Yes, but I physically spend most of my time in Greenbelt. I don’t have to go to GISS in person to do my work. The great thing about technology is that you don’t have to be in the same physical space to work with others. I have a post-doctoral fellow at GISS and we communicate constantly via Skype, emails and the phone. Both of us use the same supercomputer. My post-doctoral fellow also comes to Goddard a few times a year plus we meet at conferences throughout the year.

    Do you lead climate model teams at Goddard?

    I lead a team based at Goddard called the Interdisciplinary Science Team (IDS). We look at the recent changes in the Arctic to understand the impact and feedback of recent ice melts. Some of the changes we look at are the sea ice, clouds and aerosols and how these affect surface conditions on the Greenland ice sheet. We also try to understand how the increase in melting at the surface of the ice sheet changes the ocean, via freshening (change in the amount of salt in the water) for example, or how changes in sea ice or fresh water from the ice sheet affect phytoplankton production.

    Are you involved with teams at an agency level?

    I’m part of the NASA Sea Level Change Team, which has members from NASA centers and also from U.S. universities. Our goal is to understand how sea level is changing and better communicate that information to the public. The website is: https://sealevel.nasa.gov/

    Do you collaborate internationally?

    I travel internationally a few times a year, mainly to England and France. I co-lead an international effort called Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6, http://www.climate-cryosphere.org/activities/targeted/ismip6). Our steering committee includes eight other scientists and our members include scientists from the U.S., Japan, England, France, Denmark, Germany, Belgium and Russia.

    ISMIP6’s goal is to make better projections of global sea level rise. My role is to coordinate the effort and set the big picture. Our participants work with approximately 10 different global climate models that all include an interactive ice sheet component or will soon include this capability. We also have about twenty ice sheet models that are run outside of climate models. We will be combining the simulations from all thirty models. Our final products can be maps of future sea levels due to the ice sheets or numbers associated with possible future sea levels.

    Are your group’s projections incorporated into an international report?

    Yes, our group’s work becomes part of the International Panel on Climate Change’s report, which generally comes out every five years. Their next report, the Sixth Assessment Report (AR6), is planned for 2022. ISMIP6 is the first time that a large coordinated effort focusing on ice sheet and climate models will contribute to the IPCC report.

    Did you always want to be a scientist?

    Although both are now retired, my father is an American environmental scientist and my mother is a French environmental scientist. I wanted to be an artist or an architect, but my parents encouraged me to do science. For me, art and science are quite similar as they both require a lot of creativity.

    Where were you educated?

    I was born in northern France. I went to the University of Edinburgh in Scotland for an undergraduate degree in geophysics and a master’s degree in remote sensing and image processing. I then went to the University College London for a doctorate and post-graduate studies in glaciology.

    How did you come to work at Goddard?

    I was at a scientific conference in St. Petersburg, Russia, where I met Jay Zwally, a Goddard glaciologist. He liked my work in London and told me about Goddard. He suggested that I come for an interview. I did and I got the job. The lesson that I learned is that you never know who you are going to meet and what opportunities may come from that meeting.

    Do you have a mentor?

    My unofficial mentor is Gavin Schmidt, who is originally from England. He is a brilliant climate scientist and an amazing science communicator. When I need some advice about science or communicating, I always ask him what he thinks. When I started ISMIP6, Gavin shared with me lots of suggestions for starting and leading such an enormous international effort.

    How many post-doctoral fellows do you mentor?

    In addition to my fellow at GISS, I am currently mentoring one fellow from the NASA Post-doctoral Fellow program and one researcher at the University of Maryland. I also mentor some of the young scientists on the IDS team. I’m hoping to continue mentoring two scientists who just finished the NASA Fellow program with me.

    I always tell them: Whatever you do, do your best, as you never know who will notice.

    In 2014, I received a Robert H. Goddard Exceptional Achievement for Mentoring award for “attracting and mentoring talented students and postdocs into the challenging field of numerical modeling to improve our understanding of global climate and sea level rise.” It was such a surprise to receive this award, and I felt very fortunate that young scientists wanted to come and work with me. It is because of them that I got this award.

    What kind of art do you want to do when you have more time?

    One day, I still want to be an artist. I would like to return to acrylics painting. I love the style of Henri Matisse. I would also like to get back to making beaded jewelry. For now, my time at home is spent with our two young boys and puppy. My husband is also a scientist, who does research and teaches, so between our work and family life, we do not have much free time.

    See the full article here .

    Please help promote STEM in your local schools.

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    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
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 2:18 pm on December 15, 2016 Permalink | Reply
    Tags: 1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile", , Lake Tekapo, NASA Goddard, , New Zealand, University of Canterbury Mt John Observatory   

    From Goddard: “Microlensing Study Suggests Most Common Outer Planets Likely Neptune-mass” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Dec. 15, 2016
    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center in Greenbelt, Maryland

    A new statistical study of planets found by a technique called gravitational microlensing suggests that Neptune-mass worlds are likely the most common type of planet to form in the icy outer realms of planetary systems. The study provides the first indication of the types of planets waiting to be found far from a host star, where scientists suspect planets form most efficiently.


    Neptune-mass worlds are likely the most common type in the outer realms of planetary systems
    Credits: NASA’s Goddard Space Flight Center

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    University of Canterbury Mt John Observatory, Lake Tekapo, New Zealand

    “We’ve found the apparent sweet spot in the sizes of cold planets. Contrary to some theoretical predictions, we infer from current detections that the most numerous have masses similar to Neptune, and there doesn’t seem to be the expected increase in number at lower masses,” said lead scientist Daisuke Suzuki, a post-doctoral researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland Baltimore County. “We conclude that Neptune-mass planets in these outer orbits are about 10 times more common than Jupiter-mass planets in Jupiter-like orbits.”

    Gravitational microlensing takes advantage of the light-bending effects of massive objects predicted by Einstein’s general theory of relativity.

    Gravitational microlensing
    Gravitational microlensing, S. Liebes, Physical Review B, 133 (1964): 835

    It occurs when a foreground star, the lens, randomly aligns with a distant background star, the source, as seen from Earth. As the lensing star drifts along in its orbit around the galaxy, the alignment shifts over days to weeks, changing the apparent brightness of the source. The precise pattern of these changes provides astronomers with clues about the nature of the lensing star, including any planets it may host.

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    This graph plots 4,769 exoplanets and planet candidates according to their masses and relative distances from the snow line, the point where water and other materials freeze solid (vertical cyan line). Gravitational microlensing is particularly sensitive to planets in this region. Planets are shaded according to the discovery technique listed at right. Masses for unconfirmed planetary candidates from NASA’s Kepler mission are calculated based on their sizes. For comparison, the graph also includes the planets of our solar system.
    Credits: NASA’s Goddard Space Flight Center

    “We mainly determine the mass ratio of the planet to the host star and their separation,” said team member David Bennett, an astrophysicist at Goddard. “For about 40 percent of microlensing planets, we can determine the mass of the host star and therefore the mass of the planet.”

    More than 50 exoplanets have been discovered using microlensing compared to thousands detected by other techniques, such as detecting the motion or dimming of a host star caused by the presence of planets. Because the necessary alignments between stars are rare and occur randomly, astronomers must monitor millions of stars for the tell-tale brightness changes that signal a microlensing event.

    However, microlensing holds great potential. It can detect planets hundreds of times more distant than most other methods, allowing astronomers to investigate a broad swath of our Milky Way galaxy. The technique can locate exoplanets at smaller masses and greater distances from their host stars, and it’s sensitive enough to find planets floating through the galaxy on their own, unbound to stars.

    NASA’s Kepler and K2 missions have been extraordinarily successful in finding planets that dim their host stars, with more than 2,500 confirmed discoveries to date.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    This technique is sensitive to close-in planets but not more distant ones. Microlensing surveys are complementary, best probing the outer parts of planetary systems with less sensitivity to planets closer to their stars.

    “Combining microlensing with other techniques provides us with a clearer overall picture of the planetary content of our galaxy,” said team member Takahiro Sumi at Osaka University in Japan.

    From 2007 to 2012, the Microlensing Observations in Astrophysics (MOA) group, a collaboration between researchers in Japan and New Zealand, issued 3,300 alerts informing the astronomical community about ongoing microlensing events. Suzuki’s team identified 1,474 well-observed microlensing events, with 22 displaying clear planetary signals. This includes four planets that were never previously reported.

    To study these events in greater detail, the team included data from the other major microlensing project operating over the same period, the Optical Gravitational Lensing Experiment (OGLE), as well as additional observations from other projects designed to follow up on MOA and OGLE alerts.

    1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile1.3 meter OGLE Warsaw telescope interior
    1.3 meter OGLE Warsaw Telescope at the Las Campanas Observatory in Chile”

    From this information, the researchers determined the frequency of planets compared to the mass ratio of the planet and star as well as the distances between them. For a typical planet-hosting star with about 60 percent the sun’s mass, the typical microlensing planet is a world between 10 and 40 times Earth’s mass. For comparison, Neptune in our own solar system has the equivalent mass of 17 Earths.

    The results imply that cold Neptune-mass worlds are likely to be the most common types of planets beyond the so-called snow line, the point where water remained frozen during planetary formation. In the solar system, the snow line is thought to have been located at about 2.7 times Earth’s mean distance from the sun, placing it in the middle of the main asteroid belt today.

    3
    Neptune-mass exoplanets like the one shown in this artist’s rendering may be the most common in the icy regions of planetary systems. Beyond a certain distance from a young star, water and other substances remain frozen, leading to an abundant population of icy objects that can collide and form the cores of new planets. In the foreground, an icy body left over from this period drifts past the planet.
    Credits: NASA/Goddard/Francis Reddy

    A paper detailing the findings was published in The Astrophysical Journal on Dec. 13.

    “Beyond the snow line, materials that were gaseous closer to the star condense into solid bodies, increasing the amount of material available to start the planet-building process,” said Suzuki. “This is where we think planetary formation was most efficient, and it’s also the region where microlensing is most sensitive.”

    NASA’s Wide Field Infrared Survey Telescope (WFIRST), slated to launch in the mid-2020s, will conduct an extensive microlensing survey.

    NASA/WFIRST
    NASA/WFIRST

    Astronomers expect it will deliver mass and distance determinations of thousands of planets, completing the work begun by Kepler and providing the first galactic census of planetary properties.

    NASA’s Ames Research Center manages the Kepler and K2 missions for NASA’s Science Mission Directorate. The Jet Propulsion Laboratory (JPL) in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

    WFIRST is managed at Goddard, with participation by JPL, the Space Telescope Science Institute in Baltimore, the Infrared Processing and Analysis Center, also in Pasadena, and a science team comprising members from U.S. research institutions across the country.

    For more information on how NASA’s Kepler is working with ground-based efforts, including the MOA and OGLE groups, to search for planets using microlensing, please visit:

    https://www.nasa.gov/feature/ames/kepler/searching-for-far-out-and-wandering-worlds/

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    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
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 8:30 am on December 13, 2016 Permalink | Reply
    Tags: , NASA Goddard, ,   

    From JPL-Caltech: “Earth’s Magnetic Fields Could Track Ocean Heat: NASA” 

    NASA JPL Banner

    JPL-Caltech

    December 12, 2016
    News Media Contact
    Alan Buis
    Jet Propulsion Laboratory, Pasadena, Calif.
    818-354-0474
    alan.buis@jpl.nasa.gov

    Patrick Lynch
    NASA Goddard Space Flight Center, Greenbelt, Md.
    757-897-2047
    patrick.lynch@nasa.gov

    Written by Kate Ramsayer, NASA Goddard Space Flight Center

    1
    NASA scientists are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean. Credit: NASA Goddard Space Flight Center

    As Earth warms, much of the extra heat is stored in the planet’s ocean — but monitoring the magnitude of that heat content is a difficult task.

    A surprising feature of the tides could help, however. Scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.

    As Earth warms, much of the extra heat is stored in the planet’s ocean — but monitoring the magnitude of that heat content is a difficult task.

    A surprising feature of the tides could help, however. Scientists at aNASA’s Goddard Space Flight Center in Greenbelt, Maryland, are developing a new way to use satellite observations of magnetic fields to measure heat stored in the ocean.

    “If you’re concerned about understanding global warming, or Earth’s energy balance, a big unknown is what’s going into the ocean,” said Robert Tyler, a research scientist at Goddard. “We know the surfaces of the oceans are heating up, but we don’t have a good handle on how much heat is being stored deep in the ocean.”

    Despite the significance of ocean heat to Earth’s climate, it remains a variable that has substantial uncertainty when scientists measure it globally. Current measurements are made mainly by Argo floats, but these do not provide complete coverage in time or space. If it is successful, this new method could be the first to provide global ocean heat measurements, integrated over all depths, using satellite observations.

    Tyler’s method depends on several geophysical features of the ocean. Seawater is a good electrical conductor, so as saltwater sloshes around the ocean basins it causes slight fluctuations in Earth’s magnetic field lines. The ocean flow attempts to drag the field lines around, Tyler said. The resulting magnetic fluctuations are relatively small, but have been detected from an increasing number of events including swells, eddies, tsunamis and tides.

    “The recent launch of the European Space Agency’s Swarm satellites, and their magnetic survey, are providing unprecedented observational data of the magnetic fluctuations,” Tyler said. “With this comes new opportunities.”

    ESA/Swarm
    ESA/Swarm

    Researchers know where and when the tides are moving ocean water, and with the high-resolution data from the Swarm satellites, they can pick out the magnetic fluctuations due to these regular ocean movements.

    That’s where another geophysical feature comes in. The magnetic fluctuations of the tides depend on the electrical conductivity of the water — and the electrical conductivity of the water depends on its temperature.

    For Tyler, the question then is: “By monitoring these magnetic fluctuations, can we monitor the ocean temperature?”

    At the American Geophysical Union meeting in San Francisco this week, Tyler and collaborator Terence Sabaka, also at Goddard, presented the first results. They provide a key proof-of-concept of the method by demonstrating that global ocean heat content can be recovered from “noise-free” ocean tidal magnetic signals generated by a computer model. When they try to do this with the “noisy” observed signals, it doesn’t yet provide the accuracy needed to monitor changes in the heat content.

    But, Tyler said, there is much room for improvement in how the data are processed and modeled, and the Swarm satellites continue to collect magnetic data. This is a first attempt at using satellite magnetic data to monitor ocean heat, he said, and there is still much more to be done before the technique could successfully resolve this key variable. For example, by identifying fluctuations caused by other ocean movements, like eddies or other tidal components, scientists can extract even more information and get more refined measurements of ocean heat content and how it’s changing.

    More than 90 percent of the excess heat in the Earth system goes into the ocean, said Tim Boyer, a scientist with the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information. Scientists currently monitor ocean heat with shipboard measurements and Argo floats. While these measurements and others have seen a steady increase in heat since 1955, researchers still need more complete information, he said.

    “Even with the massive effort with the Argo floats, we still don’t have as much coverage of the ocean as we would really like in order to lower the uncertainties,” Boyer said. “If you’re able to measure global ocean heat content directly and completely from satellites, that would be fantastic.”

    Changing ocean temperatures have impacts that stretch across the globe. In Antarctica, floating sections of the ice sheet are retreating in ways that can’t be explained only by changes in atmospheric temperatures, said Catherine Walker, an ice scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

    She and her colleagues studied glaciers in Antarctica that lose an average of 6.5 to 13 feet (2 to 4 meters) of elevation per year. They looked at different options to explain the variability in melting — surrounding sea ice, winds, salinity, air temperatures — and what correlated most was influxes of warmer ocean water.

    “These big influxes of warm water come onto the continental shelf in some years and affect the rate at which ice melts,” Walker said. She and her colleagues are presenting the research at the AGU meeting.

    Walker’s team has identified an area on the Antarctic Peninsula where warmer waters may have infiltrated inland, under the ice shelf — which could have impacts on sea level rise.

    Float and ship measurements around Antarctica are scarce, but deep water temperature measurements can be achieved using tagged seals. That has its drawbacks, however: “It’s random, and we can’t control where they go,” Walker said. Satellite measurements of ocean heat content and temperatures would be very useful for the Southern Ocean, she added.

    Ocean temperatures also impact life in the ocean — from microscopic phytoplankton on up the food chain. Different phytoplankton thrive at different temperatures and need different nutrients.

    “Increased stratification in the ocean due to increased heating is going to lead to winners and losers within the phytoplankton communities,” said Stephanie Schollaert Uz, a scientist at Goddard.

    n research presented this week at AGU, she took a look 50 years back. Using temperature, sea level and other physical properties of the ocean, she generated a history of phytoplankton extent in the tropical Pacific Ocean, between 1958 and 2008. Looking over those five decades, she found that phytoplankton extent varied between years and decades. Most notably, during El Niño years, water currents and temperatures prevented phytoplankton communities from reaching as far west in the Pacific as they typically do.

    Digging further into the data, she found that where the El Niño was centered has an impact on phytoplankton. When the warmer waters of El Niño are centered over the Eastern Pacific, it suppresses nutrients across the basin, and therefore depresses phytoplankton growth more so than a central Pacific El Niño.

    “For the first time, we have a basin-wide view of the impact on biology of interannual and decadal forcing by many El Niño events over 50 years,” Uz said.

    As ocean temperatures impact processes across the Earth system, from climate to biodiversity, Tyler will continue to improve this novel magnetic remote sensing technique, to improve our future understanding of the planet.

    NASA collects data from space, air, land and sea to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

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    NASA JPL Campus

    Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. Although the facility has a Pasadena postal address, it is actually headquartered in the city of La Cañada Flintridge [1], on the northwest border of Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory’s primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA’s Deep Space Network.

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  • richardmitnick 12:29 pm on October 21, 2016 Permalink | Reply
    Tags: , , NASA Goddard,   

    From Goddard: “Photonics Dawning as the Communications Light For Evolving NASA Missions” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 21, 2016
    Ashley Hume
    ashley.l.morrow@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    A largely unrecognized field called photonics may provide solutions to some of NASA’s most pressing challenges in future spaceflight.

    Photonics explores the many applications of generating, detecting and manipulating photons, or particles of light that, among other things, make up laser beams. On this day in 1983, the General Conference of Weights and Measures adopted the accepted value for the speed of light, an important photonics milestone. Oct. 21, 2016, is Day of Photonics, a biennial event to raise awareness of photonics to the general public. The study has multiple applications across NASA missions, from space communications to reducing the size of mission payloads to performing altitude measurements from orbit.


    Access mp4 video here .
    NASA is using photonics to solve some of the most pressing upcoming challenges in spaceflight, such as better data communications from space to Earth.
    Credits: NASA’s Goddard Space Flight Center/Amber Jacobson, producer.

    One major NASA priority is to use lasers to make space communications for both near-Earth and deep-space missions more efficient. NASA’s communications systems have matured over the decades, but they still use the same radio-frequency (RF) system developed in the earliest days of the agency. After more than 50 years of using solely RF, NASA is investing in new ways to increase data rates while also finding more efficient communications systems.

    Photonics may provide the solution. Several centers across NASA are experimenting with laser communications, which has the potential to provide data rates at least 10 to 100 times better than RF. These higher speeds would support increasingly sophisticated instruments and the transmission of live video from anywhere in the solar system. They would also increase the bandwidth for communications from human exploration missions in deep space, such as those associated with Journey to Mars.

    2
    Conceptual animation depicting a satellite using lasers to relay data from Mars to Earth.
    Credits: NASA’s Goddard Space Flight Center

    NASA’s Goddard Space Flight Center in Greenbelt, Maryland, launched the first laser communications pathfinder mission in 2013. The Lunar Laser Communications Demonstration (LLCD) proved that a space-based laser communications system was viable and that the system could survive both launch and the space environment. But the mission was short-lived by design, as the host payload crashed into the lunar surface in a planned maneuver a few months after launch.

    The Goddard team is now planning a follow-on mission called the Laser Communications Relay Demonstration (LCRD) to prove the proposed system’s longevity. It will also provide engineers more opportunity to learn the best way to operate it for near-Earth missions.

    “We have been using RF since the beginning, 50 to 60 years, so we’ve learned a lot about how it works in different weather conditions and all the little things to allow us to make the most out of the technology, but we don’t have that experience with laser comm,” said Dave Israel, Exploration and Space Communications architect at Goddard and principal investigator on LCRD. “LCRD will allow us to test the performance over all different weather conditions and times of day and learn how to make the most of laser comm.”

    Scheduled to launch in 2019, LCRD will simulate real communications support, practicing for two years with a test payload on the International Space Station and two dedicated ground stations in California and Hawaii. The mission could be the last hurdle to implementing a constellation of laser communications relay satellites similar to the Space Network’s Tracking and Data Relay Satellites.

    NASA’s Jet Propulsion Laboratory in Pasadena, California, and Glenn Research Center in Cleveland are also following up on LLCD’s success. But both will focus on how laser communications could be implemented in deep-space missions.

    Missions to deep space impose special communication challenges because of their distance from Earth. The data return on these missions slowly trickle back to the ground a little at a time using radio frequency. Laser communications could significantly improve data rates in all space regions, from low-Earth orbit to interplanetary.

    JPL’s concept, called Deep Space Optical Communications (DSOC), focuses on laser communications’ benefits to data rates and to space and power constraints on missions. The data-rate benefits of laser communications for deep-space missions are clear, but less recognized is that laser communications can also save mass, space and/or power requirements on missions. That could be monumental on missions like the James Webb Space Telescope, which is so large that, even folded, it will barely fit in the largest rocket currently available. Although Webb is an extreme example, many missions today face size constraints as they become more complex. The Lunar Reconnaissance Orbiter mission carried both types of communications systems, and the laser system was half the mass, required 25 percent less power and transferred data at six times the rate of the RF system. Laser communications could also benefit a class of missions called CubeSats, which are about the size of a shoebox. These missions are becoming more popular and require miniaturized parts, including communications and power systems.

    Power requirements can become a major challenge on missions to the outer solar system. As spacecraft move away from the sun, solar power becomes less viable, so the less power a payload requires, the smaller the spacecraft battery, saving space, and the easier spacecraft components can be recharged.

    Laser communications could help to solve all of these challenges.

    The team at Glenn is developing an idea called Integrated Radio and Optical Communications (iROC) to put a laser communications relay satellite in orbit around Mars that could receive data from distant spacecraft and relay their signal back to Earth. The system would use both RF and laser communications, promoting interoperability amongst all of NASA’s assets in space. By integrating both communications systems, iROC could provide services both for new spacecraft using laser communications systems and older spacecraft like Voyager 1 that use RF.

    But laser communications is not NASA’s only foray into photonics, nor is it the first. In fact, NASA began using lasers shortly after they were invented. Goddard successfully demonstrated satellite laser ranging, a technique to measure distances, in 1964.

    Satellite Laser Ranging is still managed at Goddard. The system uses laser stations worldwide to bounce short pulses of light off of special reflectors installed on satellites. There are also reflectors on the moon that were placed there during the Apollo and Soviet rover programs. By timing the bounce of the pulses, engineers can compute distances and orbits. Measurements are accurate up to a few millimeters. This application is used on numerous NASA missions, such as ICESat-2, which will measure the altitude of the ice surface in the Antarctic and Greenland regions. It will provide important information regarding climate and the health of Earth’s polar regions.

    NASA’s Satellite Laser Ranging system consists of eight stations covering North America, the west coast of South America, the Pacific, South Africa and western Australia. NASA and its partners and associated universities operate the stations. SLR is part of the larger International Laser Ranging Service, and NASA’s contribution comprises more than a third of the organization’s total data volume.

    From communications to altimetry and navigation, photonics’ importance to NASA missions cannot be understated. As technology continues to evolve, many photonics applications may come to fruition over the next several decades. Others may also be discovered, especially as humanity pushes further out into the universe than ever before.

    To find out more, visit http://day-of-photonics.org/.

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    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.
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  • richardmitnick 7:48 am on October 18, 2016 Permalink | Reply
    Tags: NASA Goddard, , NASA's MAVEN Mission Gives Unprecedented Ultraviolet View of Mars   

    From Goddard: “NASA’s MAVEN Mission Gives Unprecedented Ultraviolet View of Mars” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 17, 2016
    Nancy Jones
    nancy.n.jones@nasa.gov

    Bill Steigerwald
    william.a.steigerwald@nasa.gov

    NASA Goddard Space Flight Center, Greenbelt, Maryland
    301-286-0039 / x-5017

    New global images of Mars from the MAVEN mission show the ultraviolet glow from the Martian atmosphere in unprecedented detail, revealing dynamic, previously invisible behavior. They include the first images of “nightglow” that can be used to show how winds circulate at high altitudes. Additionally, dayside ultraviolet imagery from the spacecraft shows how ozone amounts change over the seasons and how afternoon clouds form over giant Martian volcanoes. The images were taken by the Imaging UltraViolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile Evolution mission (MAVEN).

    NASA/Mars MAVEN
    NASA/Mars MAVEN


    Access mp4 video here .
    Images from MAVEN’s Imaging UltraViolet Spectrograph were used to make this movie of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. The movie uses four MAVEN images to show about 7 hours of Mars rotation during this period, and interleaves simulated views that would be seen between the four images. Mars’ day is similar to Earth’s, so the movie shows just over a quarter day. The left part of the planet is in morning and the right side in afternoon. Mars’ prominent volcanoes, topped with white clouds, can be seen moving across the disk. Mars’ tallest volcano, Olympus Mons, appears as a prominent dark region near the top of the images, with a small white cloud at the summit that grows during the day. Olympus Mons appears dark because the volcano rises up above much of the hazy atmosphere which makes the rest of the planet appear lighter. Three more volcanoes appear in a diagonal row, with their cloud cover merging to span up to a thousand miles by the end of the day. These images are particularly interesting because they show how rapidly and extensively the clouds topping the volcanoes form in the afternoon. Similar processes occur at Earth, with the flow of winds over mountains creating clouds. Afternoon cloud formation is a common occurrence in the American West, especially during the summer. Credits: NASA/MAVEN/University of Colorado

    “MAVEN obtained hundreds of such images in recent months, giving some of the best high-resolution ultraviolet coverage of Mars ever obtained,” said Nick Schneider of the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. Schneider is presenting these results Oct. 19 at the American Astronomical Society Division for Planetary Sciences meeting in Pasadena, California, which is being held jointly with the European Planetary Science Congress.

    Nightside images show ultraviolet (UV) “nightglow” emission from nitric oxide (abbreviated NO). Nightglow is a common planetary phenomenon in which the sky faintly glows even in the complete absence of external light. Mars’ nightside atmosphere emits light in the ultraviolet due to chemical reactions that start on Mars’ dayside. Ultraviolet light from the sun breaks down molecules of carbon dioxide and nitrogen, and the resulting atoms are carried around the planet by high-altitude wind patterns that encircle the planet. On the nightside, these winds bring the atoms down to lower altitudes where nitrogen and oxygen atoms collide to form nitric oxide molecules. The recombination releases extra energy, which comes out as ultraviolet light.

    1
    This image of the Mars night side shows ultraviolet emission from nitric oxide (abbreviated NO). The emission is shown in false color with black as low values, green as medium, and white as high. These emissions track the recombination of atomic nitrogen and oxygen produced on the dayside, and reveal the circulation patterns of the atmosphere. The splotches, streaks and other irregularities in the image are indications that atmospheric patterns are extremely variable on Mars’ nightside. The inset shows the viewing geometry on the planet. MAVEN’s Imaging UltraViolet Spectrograph obtained this image of Mars on May 4, 2016 during late winter in Mars Southern Hemisphere. Credits: NASA/MAVEN/University of Colorado.

    Scientists predicted NO nightglow at Mars, and prior missions detected its presence, but MAVEN has returned the first images of this phenomenon in the Martian atmosphere. Splotches and streaks appearing in these images occur where NO recombination is enhanced by winds. Such concentrations are clear evidence of strong irregularities in Mars’ high altitude winds and circulation patterns. These winds control how Mars’ atmosphere responds to its very strong seasonal cycles. These first images will lead to an improved determination of the circulation patterns that control the behavior of the atmosphere from approximately 37 to 62 miles (about 60 to 100 kilometers) high.

    Dayside images show the atmosphere and surface near Mars’ south pole in unprecedented ultraviolet detail. They were obtained as spring comes to the southern hemisphere. Ozone is destroyed when water vapor is present, so ozone accumulates in the winter polar region where the water vapor has frozen out of the atmosphere. The images show ozone lasting into spring, indicating that global winds are inhibiting the spread of water vapor from the rest of the planet into winter polar regions. Wave patterns in the images, revealed by UV absorption from ozone concentrations, are critical to understanding the wind patterns, giving scientists an additional means to study the chemistry and global circulation of the atmosphere.

    2
    This ultraviolet image near Mars’ South Pole was taken by MAVEN on July 10 2016 and shows the atmosphere and surface during southern spring. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. Darker regions show the planet’s rocky surface and brighter regions are due to clouds, dust and haze. The white region centered on the pole is frozen carbon dioxide (dry ice) on the surface. Pockets of ice are left inside craters as the polar cap recedes in the spring, giving its edge a rough appearance. High concentrations of atmospheric ozone appear magenta in color, and the wavy edge of the enhanced ozone region highlights wind patterns around the pole. Credits: NASA/MAVEN/University of Colorado.

    MAVEN observations also show afternoon cloud formation over the four giant volcanoes on Mars, much as clouds form over mountain ranges on Earth. IUVS images of cloud formation are among the best ever taken showing the development of clouds throughout the day. Clouds are a key to understanding a planet’s energy balance and water vapor inventory, so these observations will be valuable in understanding the daily and seasonal behavior of the atmosphere.

    3
    MAVEN’s Imaging UltraViolet Spectrograph obtained these images of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. The series interleaves MAVEN images to show about 7 hours of Mars rotation during this period, just over a quarter of Mars’ day. The left part of the planet is in morning and the right side is in afternoon. Mars’ prominent volcanoes, topped with white clouds, can be seen moving across the disk. Mars’ tallest volcano, Olympus Mons, appears as a prominent dark region near the top of the images, with a small white cloud at the summit that grows during the day. Olympus Mons appears dark because the volcano rises up above much of the hazy atmosphere which makes the rest of the planet appear lighter. Three more volcanoes appear in a diagonal row, with their cloud cover merging to span up to a thousand miles by the end of the day. These images are particularly interesting because they show how rapidly and extensively the clouds topping the volcanoes form in the afternoon. Similar processes occur at Earth, with the flow of winds over mountains creating clouds. Afternoon cloud formation is a common occurrence in the American West, especially during the summer. Credits: NASA/MAVEN/University of Colorado.

    “MAVEN’s elliptical orbit is just right,” said Justin Deighan of the University of Colorado, Boulder, who led the observations. “It rises high enough to take a global picture, but still orbits fast enough to get multiple views as Mars rotates over the course of a day.”

    4
    MAVEN’s Imaging UltraViolet Spectrograph obtained images of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. Mars’ tallest volcano, Olympus Mons, appears as a prominent dark region near the top of the image, with a small white cloud at the summit that grows during the day. Three more volcanoes appear in a diagonal row, with their cloud cover (white areas near center) merging to span up to a thousand miles by the end of the day. Credits: NASA/MAVEN/University of Colorado.

    MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics, Boulder. The university provided two science instruments and leads science operations, as well as education and public outreach, for the mission. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project and provided two science instruments for the mission. The University of California at Berkeley’s Space Sciences Laboratory also provided four science instruments for the mission. Lockheed Martin built the spacecraft and is responsible for mission operations. NASA’s Jet Propulsion Laboratory in Pasadena, California, provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.

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    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
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  • richardmitnick 7:28 am on October 18, 2016 Permalink | Reply
    Tags: , NASA Goddard, ,   

    From Goddard: “Wayward Field Lines Challenge Solar Radiation Models” 

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    NASA Goddard Space Flight Center

    Oct. 17, 2016
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    In addition to the constant emission of warmth and light, our sun sends out occasional bursts of solar radiation that propel high-energy particles toward Earth. These solar energetic particles, or SEPs, can impact astronauts or satellites. To fully understand these particles, scientists must look to their source: the bursts of solar radiation.

    But scientists aren’t exactly sure which of the two main features of solar eruptions –narrow solar flares or wide coronal mass ejections – causes the SEPs during different bursts. Scientists try to distinguish between the two possibilities by using observations, and computer models based on those observations, to map out where the particles could be found as they spread out and traveled away from the sun. NASA missions STEREO and SOHO collect the data upon which these models are built.

    NASA/STEREO spacecraft
    NASA/STEREO spacecraft

    ESA/NASA SOHO
    ESA/NASA SOHO

    Sometimes, these solar observatories saw SEPs on the opposite side of the sun than where the eruption took place. What kind of explosion on the sun could send the particles so far they ended up behind where they started?


    Access mp4 video here .
    This video compares the two models for particle distribution over the course of just three hours after an SEP event. The white line represents a magnetic field line, the general path that the SEPs follow. The line starts at an SEP event at the sun, and leads the particles in a spiral around the sun. The animation of the updated model, on the right, depicts a static field line, but as the SEPs travel farther in space, turbulent solar material causes wandering field lines. In turn, wandering field lines cause the particles to spread much more efficiently than the traditional model, on the left, predicted. Credits: NASA’s Goddard Space Flight Center/UCLan/Stanford/ULB/Joy Ng, producer

    Now a new model has been developed by an international team of scientists, led by the University of Central Lancashire and funded in part by NASA. The new model shows how particles could travel to the back of the sun no matter what type of event first propelled them. Previous models assumed the particles mainly follow the average of magnetic field lines in space on their way from the sun to Earth, and slowly spread across the average over time. The average field line forms a steady path following a distinct spiral because of the sun’s rotation. But the new model takes into consideration that magnetic fields lines can wander – a result of turbulence in solar material as it travels away from the sun.

    With this added information, models now show SEPs spiraling out much wider and farther than previous models predicted – explaining how SEPs find their way to even the far side of the sun. Understanding the nature of SEP distribution helps scientists as they continue to map out the origins of these high-energy particles. A paper published in Astronomy and Astrophysics on June 6, 2016, summarizes the research, a result of collaboration between the University of Central Lancashire, Université Libre de Bruxelles, University of Waikato and Stanford University.

    See the full article here .

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    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.
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  • richardmitnick 11:24 am on October 13, 2016 Permalink | Reply
    Tags: , , , NASA Goddard, NASA/Lunar Reconnaissance Orbiter   

    From Goddard: “Earth’s Moon Hit by Surprising Number of Meteoroids” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    Oct. 13, 2016
    Nancy Jones
    nancy.n.jones@nasa.gov

    Bill Steigerwald
    william.a.steigerwald@nasa.gov

    NASA Goddard Space Flight Center, Greenbelt, Maryland
    301-286-0039 / x-5017

    Last Updated: Oct. 13, 2016
    Editor: Bill Steigerwald

    The moon experiences a heavier bombardment by small meteoroids than models had predicted, according to new observations from NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft.

    NASA/Lunar Reconna
    NASA/Lunar Reconnaissance Orbiter

    The result implies that lunar surface features thought to be young because they have relatively few impact craters may be even younger than previous estimates.

    The finding also implies that equipment placed on the moon for long durations — such as a lunar base — may have to be made sturdier. While a direct hit from a meteoroid is still unlikely, a more intense rain of secondary debris thrown out by nearby impacts may pose a risk to surface assets.


    Access mp4 video here .
    After simulating the distant view of a new impact, the camera zooms up to the surface to show actual before/after images of a new 12-meter crater taken by the Lunar Reconnaissance Orbiter narrow-angle camera. Credits: NASA/GSFC/Ernie Wright

    “Before the launch of the Lunar Reconnaissance Orbiter, it was thought that churning of the lunar regolith (soil) from meteoroid impacts typically took millions of years to overturn the surface down to 2 centimeters (about 0.8 inches),” said Emerson Speyerer of Arizona State University, Tempe. “New images from the Lunar Reconnaissance Orbiter Camera (LROC) are revealing small surface changes that are transforming the surface much faster than previously thought.” Speyerer is lead author of a paper about this research in the Oct. 13 issue of the journal Nature.

    “The newly determined churning rate means that the Apollo astronaut tracks will be gone in tens of thousands of years rather than millions,” said Mark Robinson of Arizona State University, a co-author.

    2
    One of the first steps taken on the Moon, this is an image of Buzz Aldrin’s bootprint from the Apollo 11 mission. Neil Armstrong and Buzz Aldrin walked on the Moon on July 20, 1969. Credits: NASA

    LRO went into lunar orbit in June of 2009 and has acquired an extensive set of high-resolution images of the surface, including pairs of images of the same areas taken at different times. Using these before-and-after images (temporal pairs) acquired by the LROC Narrow Angle Camera (NAC), the team identified over 200 impact craters that formed during the LRO mission, ranging in size from about 10 to 140 feet (approximately 3 to 43 meters) in diameter.

    3
    Temporal ratio image formed from two LROC Narrow Angle Camera images (after image divided by the before image) revealing a new 12 meter (~40 foot) diameter impact crater (Latitude: 36.536°N; Longitude: 12.379°E) formed between 25 October 2012 and 21 April 2013, scene is 1300 meters (~4200 feet) wide. New crater and its continuous ejecta are seen as the small bright area in the center, dark areas are the result of material blasted out of the crater to distances much further than previously thought. Credits: NASA/GSFC/Arizona State University

    Since impact craters accumulate over time, a heavily cratered surface is older than a region with fewer craters. Knowing the number of craters that form each year is important when estimating absolute ages of the youngest regions. By analyzing the number, size distribution, and the time between each NAC temporal pair, the team estimated the contemporary cratering rate on the moon. During the search, they identified about 30 percent more new craters than anticipated by previous cratering models.

    “With this potentially higher impact rate, features with young model ages derived using crater counts and the standard rate may in fact be even younger than previously thought,” said Speyerer. “However, to be certain, we need several more years of observations and new crater discoveries.”

    In addition to discovering new impact craters, the team observed over 47,000 small surface changes, which they call splotches. They are most likely caused by small impacts, according to Speyerer. There are dense clusters of these splotches around new impact sites suggesting that many splotches may be secondary surface changes caused by material thrown out from the primary impact event.

    The team estimated their accumulation over time and from measuring their size they inferred how deeply each splotch dug up the surface and thus how long it takes to effectively churn the upper few centimeters (approximately an inch) of the regolith. The team found that 99 percent of the surface would be overturned by splotch formation after about 81,000 years. This rate is over 100 times faster than previous models that considered overturn from micrometeorite impacts alone, and ignored the effects of secondary impacts.

    “The increased churning rate will be important information for future designers of moon bases, said Speyerer. “Surface assets will have to be designed to withstand impacts from small particles moving at up to 500 meters per second (about 1,600 feet per second or 1,100 miles per hour).”

    The team also found that the new impact craters are surrounded by complex reflectance patterns related to material ejected during crater formation. Many of the larger impact craters — those greater than 10 meters in diameter — exhibit up to four distinct bright or dark reflectance zones.

    The research was funded by the LRO project. The Lunar Reconnaissance Orbiter Camera was developed at Arizona State University in Tempe. LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, as a project under NASA’s Discovery Program. The Discovery Program is managed by NASA’s Marshall Spaceflight Center in Huntsville, Alabama, for the Science Mission Directorate at NASA Headquarters in Washington.

    See the full article here .

    Please help promote STEM in your local schools.

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    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
    NASA/Goddard Campus
    NASA image

     
  • richardmitnick 4:17 pm on September 29, 2016 Permalink | Reply
    Tags: , , LMC P3, , NASA Goddard, Record-breaking Binary in Galaxy Next Door   

    From NASA Goddard and Fermi: “NASA’s Fermi Finds Record-breaking Binary in Galaxy Next Door” 

    NASA Goddard Banner

    NASA Goddard Space Flight Center

    NASA Fermi Banner


    Fermi

    Sept. 29, 2016
    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Using data from NASA’s Fermi Gamma-ray Space Telescope and other facilities, an international team of scientists has found the first gamma-ray binary in another galaxy and the most luminous one ever seen. The dual-star system, dubbed LMC P3, contains a massive star and a crushed stellar core that interact to produce a cyclic flood of gamma rays, the highest-energy form of light.

    “Fermi has detected only five of these systems in our own galaxy, so finding one so luminous and distant is quite exciting,” said lead researcher Robin Corbet at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Gamma-ray binaries are prized because the gamma-ray output changes significantly during each orbit and sometimes over longer time scales. This variation lets us study many of the emission processes common to other gamma-ray sources in unique detail.”

    These rare systems contain either a neutron star or a black hole and radiate most of their energy in the form of gamma rays. Remarkably, LMC P3 is the most luminous such system known in gamma rays, X-rays, radio waves and visible light, and it’s only the second one discovered with Fermi.


    Access mp4 video here .
    Dive into the Large Magellanic Cloud and see a visualization of LMC P3, an extraordinary gamma-ray binary system discovered by NASA’s Fermi Gamma-ray Space Telescope. Credits: NASA’s Goddard Space Flight Center/Scott Wiessinger, producer

    A paper describing the discovery will appear in the Oct. 1 issue of The Astrophysical Journal and is now available online, and you an see the full science team.

    LMC P3 lies within the expanding debris of a supernova explosion located in the Large Magellanic Cloud (LMC), a small nearby galaxy about 163,000 light-years away.

    Large Magellanic Cloud. Adrian Pingstone  December 2003
    Large Magellanic Cloud. Adrian Pingstone December 2003

    In 2012, scientists using NASA’s Chandra X-ray Observatory found a strong X-ray source within the supernova remnant and showed that it was orbiting a hot, young star many times the sun’s mass.

    NASA/Chandra Telescope
    NASA/Chandra Telescope

    The researchers concluded the compact object was either a neutron star or a black hole and classified the system as a high-mass X-ray binary (HMXB).

    In 2015, Corbet’s team began looking for new gamma-ray binaries in Fermi data by searching for the periodic changes characteristic of these systems. The scientists discovered a 10.3-day cyclic change centered near one of several gamma-ray point sources recently identified in the LMC. One of them, called P3, was not linked to objects seen at any other wavelengths but was located near the HMXB. Were they the same object?

    3
    Observations from Fermi’s Large Area Telescope (magenta line) show that gamma rays from LMC P3 rise and fall over the course of 10.3 days. The companion is thought to be a neutron star. Illustrations across the top show how the changing position of the neutron star relates to the gamma-ray cycle. Credits: NASA’s Goddard Space Flight Center

    To find out, Corbet’s team observed the binary in X-rays using NASA’s Swift satellite, at radio wavelengths with the Australia Telescope Compact Array near Narrabri and in visible light using the 4.1-meter Southern Astrophysical Research Telescope on Cerro Pachón in Chile and the 1.9-meter telescope at the South African Astronomical Observatory near Cape Town.

    NASA/SWIFT Telescope
    NASA/SWIFT Telescope

    CSIRO Australian Telescope Compact Array at the Paul Wild Observatory, about 25 km west of the town of Narrabri in rural NSW about 500 km north-west of Sydney
    CSIRO Australian Telescope Compact Array at the Paul Wild Observatory, about 25 km west of the town of Narrabri in rural NSW about 500 km north-west of Sydney, AU

    NOAO/ Southern Astrophysical Research Telescope (SOAR)telescope situated on Cerro Pachón - IV Región - Chile, at 2,700 meters (8,775 feet)
    NOAO/ Southern Astrophysical Research Telescope (SOAR)telescope situated on Cerro Pachón – IV Región – Chile

    4
    1.9-meter Radcliffe telescope at the South African Astronomical Observatory near Cape Town

    The Swift observations clearly reveal the same 10.3-day emission cycle seen in gamma rays by Fermi. They also indicate that the brightest X-ray emission occurs opposite the gamma-ray peak, so when one reaches maximum the other is at minimum. Radio data exhibit the same period and out-of-phase relationship with the gamma-ray peak, confirming that LMC P3 is indeed the same system investigated by Chandra.

    “The optical observations show changes due to binary orbital motion, but because we don’t know how the orbit is tilted into our line of sight, we can only estimate the individual masses,” said team member Jay Strader, an astrophysicist at Michigan State University in East Lansing. “The star is between 25 and 40 times the sun’s mass, and if we’re viewing the system at an angle midway between face-on and edge-on, which seems most likely, its companion is a neutron star about twice the sun’s mass.” If, however, we view the binary nearly face-on, then the companion must be significantly more massive and a black hole.

    5
    LMC P3 (circled) is located in a supernova remnant called DEM L241 in the Large Magellanic Cloud, a small galaxy about 163,000 light-years away. The system is the first gamma-ray binary discovered in another galaxy and is the most luminous known in gamma rays, X-rays, radio waves and visible light.

    Both objects form when a massive star runs out of fuel, collapses under its own weight and explodes as a supernova. The star’s crushed core may become a neutron star, with the mass of half a million Earths squeezed into a ball no larger than Washington, D.C. Or it may be further compacted into a black hole, with a gravitational field so strong not even light can escape it.

    The surface of the star at the heart of LMC P3 has a temperature exceeding 60,000 degrees Fahrenheit (33,000 degrees Celsius), or more than six times hotter than the sun’s. The star is so luminous that pressure from the light it emits actually drives material from the surface, creating particle outflows with speeds of several million miles an hour.

    In gamma-ray binaries, the compact companion is thought to produce a “wind” of its own, one consisting of electrons accelerated to near the speed of light. The interacting outflows produce X-rays and radio waves throughout the orbit, but these emissions are detected most strongly when the compact companion travels along the part of its orbit closest to Earth.

    Through a different mechanism, the electron wind also emits gamma rays. When light from the star collides with high-energy electrons, it receives a boost to gamma-ray levels. Called inverse Compton scattering, this process produces more gamma rays when the compact companion passes near the star on the far side of its orbit as seen from our perspective.

    Prior to Fermi’s launch, gamma-ray binaries were expected to be more numerous than they’ve turned out to be. Hundreds of HMXBs are cataloged, and these systems are thought to have originated as gamma-ray binaries following the supernova that formed the compact object.

    “It is certainly a surprise to detect a gamma-ray binary in another galaxy before we find more of them in our own,” said Guillaume Dubus, a team member at the Institute of Planetology and Astrophysics of Grenoble in France. “One possibility is that the gamma-ray binaries Fermi has found are rare cases where a supernova formed a neutron star with exceptionally rapid spin, which would enhance how it produces accelerated particles and gamma rays.”

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the U.S. Department of Energy and with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

    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
    NASA/Goddard Campus

    NASA image

     
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