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  • richardmitnick 2:43 pm on January 25, 2018 Permalink | Reply
    Tags: , , , , NASA Goddard, NASA Poised to Topple a Planet-Finding Barrier, Ultra-Stable Thermal Vacuum system   

    From Goddard: “NASA Poised to Topple a Planet-Finding Barrier” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 25, 2018
    Lori Keesey
    NASA’s Goddard Space Flight Center

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    Goddard optics experts Babak Saif (left) and Lee Feinberg (right), with help from engineer Eli Griff-McMahon an employee of Genesis, have created an Ultra-Stable Thermal Vacuum system that they will use to make picometer-level measurements. Credits: NASA/W. Hrybyk

    NASA optics experts are well on the way to toppling a barrier that has thwarted scientists from achieving a long-held ambition: building an ultra-stable telescope that locates and images dozens of Earth-like planets beyond the solar system and then scrutinizes their atmospheres for signs of life.

    Babak Saif and Lee Feinberg at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, have shown for the first time that they can dynamically detect subatomic- or picometer-sized distortions — changes that are far smaller than an atom — across a five-foot segmented telescope mirror and its support structure. Collaborating with Perry Greenfield at the Space Telescope Science Institute in Baltimore, the team now plans to use a next-generation tool and thermal test chamber to further refine their measurements.

    The measurement feat is good news to scientists studying future missions for finding and characterizing extrasolar Earth-like planets that potentially could support life.

    To find life, these observatories would have to gather and focus enough light to distinguish the planet’s light from that of its much brighter parent star and then be able to dissect that light to discern different atmospheric chemical signatures, such as oxygen and methane. This would require a super-stable observatory whose optical components move or distort no more than 12 picometers, a measurement that is about one-tenth the size of a hydrogen atom.

    To date, NASA has not built an observatory with such demanding stability requirements.

    How Displacements Occur

    Displacements and movement occur when materials used to build telescopes shrink or expand due to wildly fluctuating temperatures, such as those experienced when traveling from Earth to the frigidity of space, or when exposed to fierce launch forces more than six-and-a-half times the force of gravity.

    Scientists say that even nearly imperceptible, atomic-sized movements would affect a future observatory’s ability to gather and focus enough light to image and analyze the planet’s light. Consequently, mission planners must design telescopes to picometer accuracies and then test it at the same level across the entire structure, not just between the telescope’s reflective mirrors. Movement occurring at any particular position might not accurately reflect what’s actually happening in other locations.

    “These future missions will require an incredibly stable observatory,” said Azita Valinia, deputy Astrophysics Projects Division program manager. “This is one of the highest technology tall poles that future observatories of this caliber must overcome. The team’s success has shown that we are steadily whittling away at that particular obstacle.”

    The Initial Test

    To carry out the test, Saif and Feinberg used the High-Speed Interferometer, or HSI — an instrument that the Arizona-based 4D Technology developed to measure nanometer-sized dynamic changes in the James Webb Space Telescope’s optical components — including its 18 mirror segments, mounts, and other supporting structures — during thermal, vibration and other types of environmental testing.

    Like all interferometers, the instrument splits light and then recombines it to measure tiny changes, including motion. The HSI can quickly measure dynamic changes across the mirror and other structural components, giving scientists insights into what is happening all across the telescope, not just in one particular spot.

    Even though the HSI was designed to measure nanometer or molecule-sized distortions — which was the design standard for Webb — the team wanted to see it could use the same instrument, coupled with specially developed algorithms, to detect even smaller changes over the surface of a spare five-foot Webb mirror segment and its support hardware.

    The test proved it could, measuring dynamic movement as small as 25 picometers — about twice the desired target, Saif said.

    Next Steps

    However, Goddard and 4D Technology have designed a new high-speed instrument, called a speckle interferometer, that allows measurements of both reflective and diffuse surfaces at picometer accuracies. 4D Technology has built the instrument and the Goddard team has begun initial characterization of its performance in a new thermal-vacuum test chamber that controls internal temperatures to a frosty 1-millikelvin.

    Saif and Feinberg plan to place test items inside the chamber to see if they can achieve the 12-picometer target accuracy.

    “I think we’ve made a lot of progress. We’re getting there,” Saif said.

    For more Goddard technology news, go to https://www.nasa.gov/sites/default/files/atoms/files/winter_2018_final_lowrez.pdf

    See the full article here.

    Please help promote STEM in your local schools.

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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

     
  • richardmitnick 1:35 pm on January 12, 2018 Permalink | Reply
    Tags: , , , , , NASA Goddard, No Planets Needed: NASA Study Shows Disk Patterns Can Self-Generate   

    From Goddard: “No Planets Needed: NASA Study Shows Disk Patterns Can Self-Generate” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 11, 2018
    Jeanette Kazmierczak
    jeanette.a.kazmierczak@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    When scientists searching for exoplanets — worlds located beyond our solar system — first spotted patterns in disks of dust and gas around young stars, they thought newly formed planets might be the cause. But a recent NASA study cautions that there may be another explanation — one that doesn’t involve planets at all.

    Exoplanet hunters watch stars for a few telltale signs that there might be planets in orbit, like changes in the color and brightness of the starlight. For young stars, which are often surrounded by disks of dust and gas, scientists look for patterns in the debris — such as rings, arcs and spirals — that might be caused by an orbiting world.

    “We’re exploring what we think is the leading alternative contender to the planet hypothesis, which is that the dust and gas in the disk form the patterns when they get hit by ultraviolet light,” said Marc Kuchner, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.


    Astronomers thought patterns spotted in disks around young stars could be planetary signposts. But is there another explanation? A new simulation performed on NASA’s Discover supercomputing cluster shows how the dust and gas in the disk could form those patterns — no planets needed. Credits: NASA’s Goddard Space Flight Center

    Kuchner presented the findings of the new study on Thursday, Jan. 11, at the American Astronomical Society meeting in Washington. A paper describing the results has been submitted to The Astrophysical Journal.

    When high-energy UV starlight hits dust grains, it strips away electrons. Those electrons collide with and heat nearby gas. As the gas warms, its pressure increases and it traps more dust, which in turn heats more gas. The resulting cycle, called the photoelectric instability (PeI), can work in tandem with other forces to create some of the features astronomers have previously associated with planets in debris disks.

    Kuchner and his colleagues designed computer simulations to better understand these effects. The research was led by Alexander Richert, a doctoral student at Penn State in University Park, Pennsylvania, and includes Wladimir Lyra, a professor of astronomy at California State University, Northridge and research associate at NASA’s Jet Propulstion Laboratory in Pasadena, California. The simulations were run on the Discover supercomputing cluster at the NASA Center for Climate Simulation at Goddard.

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    NCCS Discover Linux supercomputing cluster

    In 2013, Lyra and Kuchner suggested that PeI could explain the narrow rings seen in some disks. Their model also predicted that some disks would have arcs, or incomplete rings, which were first directly observed in 2016 [Astronomy and Astrophysics].

    “People very often model these systems with planets, but if you want to know what a disk with a planet looks like, you first have to know what a disk looks like without a planet,” Richert said.

    Richert is lead author on the new study, which builds on Lyra and Kuchner’s previous simulations by including an additional new factor: radiation pressure, a force caused by starlight striking dust grains.

    Light exerts a minute physical force on everything it encounters. This radiation pressure propels solar sails and helps direct comet tails so they always point away from the Sun. The same force can push dust into highly eccentric orbits, and even blow some of the smaller grains out of the disk entirely.

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    Arcs, rings and spirals appear in the debris disk around the star HD 141569A. The black region in the center is caused by a mask that blocks direct light from the star. This image incorporates observations made in June and August 2015 using the Hubble Space Telescope’s STIS instrument.
    Credits: NASA/Hubble/Konishi et al. 2016

    The researchers modeled how radiation pressure and PeI work together to affect the movement of dust and gas. They also found that the two forces manifest different patterns depending on the physical properties of the dust and gas.

    The 2013 simulations of PeI revealed how dust and gas interact to create rings and arcs, like those observed around the real star HD 141569A. With the inclusion of radiation pressure, the 2017 models show how these two factors can create spirals like those also observed around the same star. While planets can also cause these patterns, the new models show scientists should avoid jumping to conclusions.

    “Carl Sagan used to say extraordinary claims require extraordinary evidence,” Lyra said. “I feel we are sometimes too quick to jump to the idea that the structures we see are caused by planets. That is what I consider an extraordinary claim. We need to rule out everything else before we claim that.”

    Kuchner and his colleagues said they would continue to factor other parameters into their simulations, like turbulence and different types of dust and gas. They also intend to model how these factors might contribute to pattern formation around different types of stars.

    A NASA-funded citizen science project spearheaded by Kuchner, called Disk Detective, aims to discover more stars with debris disks. So far, participants have contributed more than 2.5 million classifications of potential disks. The data has already helped break new ground [Astrophysical Journal Letters]in this research.

    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

     
  • richardmitnick 11:14 am on January 11, 2018 Permalink | Reply
    Tags: , , , , NASA Goddard, NASA Team First to Demonstrate X-ray Navigation in Space, , NASA/Sextant   

    From Goddard: “NASA Team First to Demonstrate X-ray Navigation in Space” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 11, 2018
    Lori Keesey
    Clare Skelly
    Goddard Space Flight Center

    1
    This illustration shows the NICER mission at work aboard the International Space Station. Credits: NASA’s Goddard Space Flight Center.

    In a technology first, a team of NASA engineers has demonstrated fully autonomous X-ray navigation in space — a capability that could revolutionize NASA’s ability in the future to pilot robotic spacecraft to the far reaches of the solar system and beyond.

    The demonstration, which the team carried out with an experiment called Station Explorer for X-ray Timing and Navigation Technology, or SEXTANT, showed that millisecond pulsars could be used to accurately determine the location of an object moving at thousands of miles per hour in space — similar to how the Global Positioning System, widely known as GPS, provides positioning, navigation, and timing services to users on Earth with its constellation of 24 operating satellites.

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    NASA Sextant.

    2
    NICER’s mirror assemblies concentrate X-rays onto silicon detectors to gather data that probes the interior makeup of neutron stars, including those that appear to flash regularly, called pulsars. Credits: NASA’s Goddard Space Flight Center/Keith Gendreau.

    “This demonstration is a breakthrough for future deep space exploration,” said SEXTANT Project Manager Jason Mitchell, an aerospace technologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “As the first to demonstrate X-ray navigation fully autonomously and in real-time in space, we are now leading the way.”

    This technology provides a new option for deep space navigation that could work in concert with existing spacecraft-based radio and optical systems.

    Although it could take a few years to mature an X-ray navigation system practical for use on deep-space spacecraft, the fact that NASA engineers proved it could be done bodes well for future interplanetary space travel. Such a system provides a new option for spacecraft to autonomously determine their locations outside the currently used Earth-based global navigation networks because pulsars are accessible in virtually every conceivable fight regime, from low-Earth to deepest space.

    Exploiting NICER Telescopes

    The SEXTANT technology demonstration, which NASA’s Space Technology Mission Directorate had funded under its Game Changing Program, took advantage of the 52 X-ray telescopes and silicon-drift detectors that make up NASA’s Neutron-star Interior Composition Explorer, or NICER.

    NASA/NICER

    Since its successful deployment as an external attached payload on the International Space Station in June, it has trained its optics on some of the most unusual objects in the universe.

    “We’re doing very cool science and using the space station as a platform to execute that science, which in turn enables X-ray navigation,” said Goddard’s Keith Gendreau, the principal investigator for NICER, who presented the findings Thursday, Jan. 11, at the American Astronomical Society meeting in Washington. “The technology will help humanity navigate and explore the galaxy.”

    NICER, an observatory about the size of a washing machine, currently is studying neutron stars and their rapidly pulsating cohort, called pulsars. Although these stellar oddities emit radiation across the electromagnetic spectrum, observing in the X-ray band offers the greatest insights into these unusual, incredibly dense celestial objects, which, if compressed any further, would collapse completely into black holes. Just one teaspoonful of neutron star matter would weigh a billion tons on Earth.

    Although NICER is studying all types of neutron stars, the SEXTANT experiment is focused on observations of pulsars. Radiation emanating from their powerful magnetic fields is swept around much like a lighthouse. The narrow beams are seen as flashes of light when they sweep across our line of sight. With these predictable pulsations, pulsars can provide high-precision timing information similar to the atomic-clock signals supplied through the GPS system.

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    This animation shows how NICER scans the sky and highlights the mission’s main features. Credits: NASA’s Goddard Space Flight Center

    Veteran’s Day Demonstration

    n the SEXTANT demonstration that occurred over the Veteran’s Day holiday in 2017, the SEXTANT team selected four millisecond pulsar targets — J0218+4232, B1821-24, J0030+0451, and J0437-4715 — and directed NICER to orient itself so it could detect X-rays within their sweeping beams of light. The millisecond pulsars used by SEXTANT are so stable that their pulse arrival times can be predicted to accuracies of microseconds for years into the future.

    During the two-day experiment, the payload generated 78 measurements to get timing data, which the SEXTANT experiment fed into its specially developed onboard algorithms to autonomously stitch together a navigational solution that revealed the location of NICER in its orbit around Earth as a space station payload. The team compared that solution against location data gathered by NICER’s onboard GPS receiver.

    “For the onboard measurements to be meaningful, we needed to develop a model that predicted the arrival times using ground-based observations provided by our collaborators at radio telescopes around the world,” said Paul Ray, a SEXTANT co-investigator with the U. S. Naval Research Laboratory. “The difference between the measurement and the model prediction is what gives us our navigation information.”

    The goal was to demonstrate that the system could locate NICER within a 10-mile radius as the space station sped around Earth at slightly more than 17,500 mph. Within eight hours of starting the experiment on November 9, the system converged on a location within the targeted range of 10 miles and remained well below that threshold for the rest of the experiment, Mitchell said. In fact, “a good portion” of the data showed positions that were accurate to within three miles.

    “This was much faster than the two weeks we allotted for the experiment,” said SEXTANT System Architect Luke Winternitz, who works at Goddard. “We had indications that our system would work, but the weekend experiment finally demonstrated the system’s ability to work autonomously.”

    Although the ubiquitously used GPS system is accurate to within a few feet for Earth-bound users, this level of accuracy is not necessary when navigating to the far reaches of the solar system where distances between objects measure in the millions of miles. “In deep space, we hope to reach accuracies in the hundreds of feet,” Mitchell said.

    Next Steps and the Future

    Now that the team has demonstrated the system, Winternitz said the team will focus on updating and fine-tuning both flight and ground software in preparation for a second experiment later in 2018. The ultimate goal, which may take years to realize, would be to develop detectors and other hardware to make pulsar-based navigation readily available on future spacecraft. To advance the technology for operational use, teams will focus on reducing the size, weight, and power requirements and improving the sensitivity of the instruments. The SEXTANT team now also is discussing the possible application of X-ray navigation to support human spaceflight, Mitchell added.

    If an interplanetary mission to the moons of Jupiter or Saturn were equipped with such a navigational device, for example, it would be able to calculate its location autonomously, for long periods of time without communicating with Earth.

    Mitchell said that GPS is not an option for these far-flung missions because its signal weakens quickly as one travels beyond the GPS satellite network around Earth.

    “This successful demonstration firmly establishes the viability of X-ray pulsar navigation as a new autonomous navigation capability. We have shown that a mature version of this technology could enhance deep-space exploration anywhere within the solar system and beyond,” Mitchell said. “It is an awesome technology first.”

    NICER is an Astrophysics Mission of Opportunity within NASA’s Explorers program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA’s Space Technology Mission Directorate funds the SEXTANT component of the mission through its Game Changing Development Program.

    Related Links:

    NASA’s NICER mission website
    More information on SEXTANT
    Download NICER-SEXTANT multimedia resources

    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

     
  • richardmitnick 3:05 pm on January 3, 2018 Permalink | Reply
    Tags: , , , , , Magnetospheric Multiscale Mission, NASA Goddard, or MMS   

    From Goddard: “NASA’s Magnetospheric Multiscale Mission Locates Elusive Electron Act” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Jan. 3, 2018
    Mara Johnson-Groh
    mara.johnson-groh@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    The space high above Earth may seem empty, but it’s a carnival packed with magnetic field lines and high-energy particles. This region is known as the magnetosphere and, every day, charged particles put on a show as they dart and dive through it.

    Magnetosphere of Earth, original bitmap from NASA. SVG rendering by Aaron Kaase

    Like tiny tightrope walkers, the high-energy electrons follow the magnetic field lines. Sometimes, such as during an event called magnetic reconnection where the lines explosively collide, the particles are shot off their trajectories, as if they were fired from a cannon.

    Since these acts can’t be seen by the naked eye, NASA uses specially designed instruments to capture the show. The Magnetospheric Multiscale Mission, or MMS, is one such looking glass through which scientists can observe the invisible magnetic forces and pirouetting particles that can impact our technology on Earth. New research uses MMS data to improve understanding of how electrons move through this complex region — information that will help untangle how such particle acrobatics affect Earth.

    NASA/MMS

    NASA MMS satellites in space


    This visualization shows the motion of one electron in the magnetic reconnection region. As the spacecraft approaches the reconnection region, it detects first high-energy particles, then low-energy particles. Credits: NASA’s Goddard Space Flight Center/Tom Bridgman

    Scientists with MMS have been watching the complex shows electrons put on around Earth and have noticed that electrons at the edge of the magnetosphere often move in rocking motions as they are accelerated. Finding these regions where electrons are accelerated is key to understanding one of the mysteries of the magnetosphere: How does the magnetic energy seething through the area get converted to kinetic energy — that is, the energy of particle motion. Such information is important to protect technology on Earth, since particles that have been accelerated to high energies can at their worst cause power grid outages and GPS communications dropouts.

    New research, published in the Journal of Geophysical Research, found a novel way to help locate regions where electrons are accelerated. Until now, scientists looked at low-energy electrons to find these accelerations zones, but a group of scientists lead by Matthew Argall of the University of New Hampshire in Durham has shown it’s possible, and in fact easier, to identify these regions by watching high-energy electrons.

    This research is only possible with the unique design of MMS, which uses four spacecraft flying in a tight tetrahedral formation to give high temporal and spatial resolution measurements of the magnetic reconnection region.

    “We’re able to probe very small scales and this helps us to really pinpoint how energy is being converted through magnetic reconnection,” Argall said.

    The results will make it easier for scientists to identify and study these regions, helping them explore the microphysics of magnetic reconnection and better understand electrons’ effects on Earth.

    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

     
  • richardmitnick 8:51 am on December 22, 2017 Permalink | Reply
    Tags: , , , , , NASA Goddard, New Study Finds 'Winking' Star May Be Devouring Wrecked Planets, RZ Piscium   

    From Goddard via Manu: “New Study Finds ‘Winking’ Star May Be Devouring Wrecked Planets” 


    Manu Garcia, a friend from IAC.

    The universe around us.
    Astronomy, everything you wanted to know about our local universe and never dared to ask.

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Dec. 21, 2017

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

    A team of U.S. astronomers studying the star RZ Piscium has found evidence suggesting its strange, unpredictable dimming episodes may be caused by vast orbiting clouds of gas and dust, the remains of one or more destroyed planets.

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    RZ Piscium, located in the constellation Pisces, is surrounded by huge dust clouds that appear to be the remains of one or more destroyed planets. Photo: NASA

    “Our observations show there are massive blobs of dust and gas that occasionally block the star’s light and are probably spiraling into it,” said Kristina Punzi, a doctoral student at the Rochester Institute of Technology (RIT) in New York and lead author of a paper describing the findings. “Although there could be other explanations, we suggest this material may have been produced by the break-up of massive orbiting bodies near the star.”


    Zoom into RZ Piscium, a star about 550 light-years away that undergoes erratic dips in brightness. This animation illustrates one possible interpretation of the system, with a giant planet near the star slowly dissolving. Gas and dust intermittently stream away from the planet, and these clouds occasionally eclipse the star as we view it from Earth. Credits: NASA’s Goddard Space Flight Center/CI Lab.

    RZ Piscium is located about 550 light-years away in the constellation Pisces. During its erratic dimming episodes, which can last as long as two days, the star becomes as much as 10 times fainter. It produces far more energy at infrared wavelengths than emitted by stars like our Sun, which indicates the star is surrounded by a disk of warm dust. In fact, about 8 percent of its total luminosity is in the infrared, a level matched by only a few of the thousands of nearby stars studied over the past 40 years. This implies enormous quantities of dust.

    These and other observations led some astronomers to conclude that RZ Piscium is a young Sun-like star surrounded by a dense asteroid belt, where frequent collisions grind the rocks to dust.

    But the evidence was far from clear. An alternative view suggests the star is instead somewhat older than our Sun and just beginning its transition into the red giant stage. A dusty disk from the star’s youth would have dispersed after a few million years, so astronomers needed another source of dust to account for the star’s infrared glow. Because the aging star is growing larger, it would doom any planets in close orbits, and their destruction could provide the necessary dust.

    So which is it, a young star with a debris disk or a planet-smashing stellar senior? According to the research by Punzi and her colleagues, RZ Piscium is a bit of both.

    The team investigated the star using the European Space Agency’s (ESA) XMM-Newton satellite, the Shane 3-meter telescope at Lick Observatory in California and the 10-meter Keck I telescope at W. M. Keck Observatory in Hawaii.

    ESA/XMM Newton X-ray telescope

    The UCO Lick C. Donald Shane telescope is a 120-inch (3.0-meter) reflecting telescope located at the Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)

    UCSC Lick Observatory, Mt Hamilton, in San Jose, California, Altitude 1,283 m (4,209 ft)


    Keck Observatory, Maunakea, Hawaii, USA.4,207 m (13,802 ft), above sea level, showing also NASA’s IRTF and NAOJ Subaru

    Young stars are often prodigious X-ray sources. Thanks to 11 hours of XMM-Newton observations, Punzi’s team shows that RZ Piscium is, too. Its total X-ray output is roughly 1,000 times greater than our Sun’s, essentially clinching the case for stellar youth.

    The team’s ground-based observations revealed the star’s surface temperature to be about 9,600 degrees Fahrenheit (5,330 degrees Celsius), only slightly cooler than the Sun’s. They also show the star is enriched in the tell-tale element lithium, which is slowly destroyed by nuclear reactions inside stars.

    “The amount of lithium in a star’s surface declines as it ages, so it serves as a clock that allows us to estimate the elapsed time since a star’s birth,” said co-author Joel Kastner, director of RIT’s Laboratory for Multiwavelength Astrophysics. “Our lithium measurement for RZ Piscium is typical for a star of its surface temperature that is about 30 to 50 million years old.”

    So while the star is young, it’s actually too old to be surrounded by so much gas and dust. “Most Sun-like stars have lost their planet-forming disks within a few million years of their birth,” said team member Ben Zuckerman, an astronomy professor at the University of California, Los Angeles. “The fact that RZ Piscium hosts so much gas and dust after tens of millions of years means it’s probably destroying, rather than building, planets.”

    Ground-based observations also probed the star’s environment, capturing evidence that the dust is accompanied by substantial amounts of gas. Based on the temperature of the dust, around 450 degrees F (230 degrees C), the researchers think most of the debris is orbiting about 30 million miles (50 million kilometers) from the star.

    “While we think the bulk of this debris is about as close to the star as the planet Mercury ever gets to our Sun, the measurements also show variable and rapidly moving emission and absorption from hydrogen-rich gas,” said co-author Carl Melis, an associate research scientist at the University of California, San Diego. “Our measurements provide evidence that material is both falling inward toward the star and also flowing outward.”

    A paper reporting the findings was published Thurs., Dec. 21, in The Astronomical Journal.

    The best explanation that accounts for all of the available data, say the researchers, is that the star is encircled by debris representing the aftermath of a disaster of planetary proportions. It’s possible the star’s tides may be stripping material from a close substellar companion or giant planet, producing intermittent streams of gas and dust, or that the companion is already completely dissolved. Another possibility is that one or more massive gas-rich planets in the system underwent a catastrophic collision in the astronomically recent past.

    ESA’s XMM-Newton observatory was launched in December 1999 from Kourou, French Guiana. NASA funded elements of the XMM-Newton instrument package and provides the NASA Guest Observer Facility at Goddard, which supports use of the observatory by U.S. astronomers.

    See the full Goddard article here.
    See Manu Garcia’s full article here. Look near the top for the language translator.

    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

     
  • richardmitnick 11:09 am on December 21, 2017 Permalink | Reply
    Tags: , , , , , , Mission to the sun: Special delivery - Parker Solar Probe heads to NASA's Goddard Space Flight Center for environmental testing, NASA Goddard,   

    From JHU HUB- “Mission to the sun: Special delivery – Parker Solar Probe heads to NASA’s Goddard Space Flight Center for environmental testing” 

    Johns Hopkins
    JHU HUB

    12.20.17
    Hub staff report

    Spacecraft designed, built at JHU’s Applied Physics Lab is scheduled for launch in 2018.

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    The Parker Solar Probe team at Johns Hopkins APL prepares to lift the heat shield in preparation for shipment to NASA’s Goddard Space Flight Center. Image credit: NASA / Johns Hopkins APL / Ed Whitman.

    How do you prepare to move the first spacecraft to touch the sun? The same way you would move anything else: carefully wrap it, pack it, rent a truck, and perform a nitrogen purge.

    Last month, the Parker Solar Probe spacecraft traveled from the Johns Hopkins Applied Physics Laboratory, where it was designed and built, to NASA’s Goddard Space Flight Center in Greenbelt, Maryland. It’s a short drive, but it took significant preparation.

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    NASA’s Parker Solar Probe, shown in protective bagging to prevent contamination, is mounted on a rotating pedestal. Image credit: NASA / Johns Hopkins APL / Ed Whitman

    First, the spacecraft was wrapped in a special protective layer to prevent dust or dirt from reaching the probe. Then it was bolted to a specially designed pedestal that carefully tilted the probe onto its side to fit it inside a shipping container. If kept upright, the probe would have been too tall to pass under highway bridges during transport.

    Once boxed and loaded onto a truck bed, the scientists performed a nitrogen purge, slowly sucking air and moisture out of the container and replacing it with ultra-dry nitrogen with an extremely low dew point. A nitrogen purge is a common practice among military and commercial aerospace projects to prevent corrosive moisture and condensation from reaching sensitive electronics.

    3
    Image credit: NASA / Johns Hopkins APL / Ed Whitman

    The move, accompanied by a state police escort, took place at 4 a.m.—to avoid traffic, of course.

    4
    No, it’s not a still from the movie E.T., it’s members of the testing team preparing the Parker Solar Probe for environmental testing in the Acoustic Test Chamber at NASA’s Goddard Space Flight Center. Image credit: NASA / Johns Hopkins APL / Ed Whitman.

    At Goddard, the Parker Solar Probe has undergone extensive testing and simulations to ensure it’s ready for its historic mission next year (launch is scheduled for between July 31 and Aug. 19).

    It underwent an acoustic test, which subjected the probe to sound forces like those generated during a rocket launch. Goddard’s Acoustic Test Chamber is a 42-foot-tall chamber that uses 6-foot-tall speakers that can reach 150 decibels to simulate the extreme noise of the Delta IV Heavy, the highest-capacity rocket currently in operation and the vehicle that will carry the probe into space.

    The spacecraft’s specially designed Thermal Protection System, or TPS, has also gone through thorough testing. The heat shield, developed by scientists at APL and the Whiting School of Engineering, is made of carbon-carbon composite material to protect the probe from the intense heat of the sun’s atmosphere, which can reach temperatures of almost 2,500 degrees Fahrenheit. As the spacecraft hurtles through the hot solar atmosphere and back out into outer space, the TPS will keep the instruments on the spacecraft at approximately room temperature.

    5
    The probe’s Thermal Protection System is lowered into the Thermal Vacuum Chamber at NASA’s Goddard Space Flight Center in preparation for environmental testing. Image credit: NASA / Johns Hopkins APL / Ed Whitman.

    The heat shield was tested in Goddard’s Thermal Vacuum Chamber, which simulated the harsh conditions that it will endure during the mission.

    During its mission, the Parker Solar Probe will use seven Venus flybys over the course of nearly seven years to gradually shrink its orbit around the sun, coming as close as 3.7 million miles—about eight times closer to the sun than any spacecraft has come before. Upon its closest orbit, the Parker Solar Probe will be traveling at about 450,000 miles per hour. That’s fast enough to get from Philadelphia to Washington, D.C., in one second.

    The solar probe, named for Eugene Parker, the astrophysicist who predicted the existence of the solar wind in 1958, is a “true mission of exploration,” the scientists write on the mission homepage. “Still, as with any great mission of discovery, Parker Solar Probe is likely to generate more questions than it answers.”

    See the full article here .

    Please help promote STEM in your local schools.
    STEM Icon

    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 3:43 pm on December 18, 2017 Permalink | Reply
    Tags: , , , , , NASA Goddard, NASA Solves How a Jupiter Jet Stream Shifts into Reverse, QQO-Jupiter’s cycle is called the quasi-quadrennial oscillation, Speeding through the atmosphere high above Jupiter’s equator is an east–west jet stream that reverses course on a schedule almost as predictable as a Tokyo train’s, Texas Echelon Cross Echelle Spectrograph at IRTF   

    From Goddard: “NASA Solves How a Jupiter Jet Stream Shifts into Reverse” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Dec. 18, 2017
    Elizabeth Zubritsky
    elizabeth.a.zubritsky@nasa.gov
    NASA’s Goddard Space Flight Center in Greenbelt, Md.

    1
    Illustration showing Jupiter and its moon Io. Credit: NASA’s Goddard Space Flight Center/CI Lab

    Speeding through the atmosphere high above Jupiter’s equator is an east–west jet stream that reverses course on a schedule almost as predictable as a Tokyo train’s. Now, a NASA-led team has identified which type of wave forces this jet to change direction.

    Similar equatorial jet streams have been identified on Saturn and on Earth, where a rare disruption of the usual wind pattern complicated weather forecasts in early 2016. The new study combines modeling of Jupiter’s atmosphere with detailed observations made over the course of five years from NASA’s Infrared Telescope Facility, or IRTF, in Hawai’i.

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA, 4,207 m (13,802 ft) above sea level

    The findings could help scientists better understand the dynamic atmosphere of Jupiter and other planets, including those beyond our solar system.


    New observations and modeling by a NASA-led team can help scientists understand a fast and furious jet stream high above Jupiter’s equator. This jet has a counterpart on Earth that seems to influence the transport of ozone, water vapor and pollution in the upper atmosphere, as well as the production of hurricanes.
    Credits: NASA’s Goddard Space Flight Center/Scientific Visualization Studio/Dan Gallagher

    “Jupiter is much bigger than Earth, much farther from the Sun, rotates much faster, and has a very different composition, but it turns out to be an excellent laboratory for understanding this equatorial phenomenon,” said Rick Cosentino, a postdoctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the paper published in the Journal of Geophysical Research-Planets.

    Earth’s equatorial jet stream was discovered after observers saw debris from the 1883 eruption of the Krakatoa volcano being carried by a westward wind in the stratosphere, the region of the atmosphere where modern airplanes achieve cruising altitude. Later, weather balloons documented an eastward wind in the stratosphere. Scientists eventually determined that these winds reversed course regularly and that both cases were part of the same phenomenon.

    The alternating pattern starts in the lower stratosphere and propagates down to the boundary with the troposphere, or lowest layer of the atmosphere. In its eastward phase, it’s associated with warmer temperatures. The westward phase is associated with cooler temperatures. The pattern is called Earth’s quasi-biennial oscillation, or QBO, and one cycle lasts about 28 months. The phase of the QBO seems to influence the transport of ozone, water vapor and pollution in the upper atmosphere as well as the production of hurricanes.

    Jupiter’s cycle is called the quasi-quadrennial oscillation, or QQO, and it lasts about four Earth years. Saturn has its own version of the phenomenon, the quasi-periodic oscillation, with a duration of about 15 Earth years. Researchers have a general understanding of these patterns but are still working out how much various types of atmospheric waves contribute to driving the oscillations and how similar the phenomena are to each other.

    Previous studies of Jupiter had identified the QQO by measuring temperatures in the stratosphere to infer wind speed and direction. The new set of measurements is the first to span one full cycle of the QQO and covers a much larger area of Jupiter. Observations extended over a large vertical range and spanned latitudes from about 40 degrees north to about 40 degrees south. The team achieved this by mounting a high-resolution instrument called TEXES, short for Texas Echelon Cross Echelle Spectrograph, on the IRTF.

    3
    The TEXES (Texas Echelon Cross Echelle Spectrograph) at IRTF. http://bjm.scs.illinois.edu/astronomy/new_molecules.php

    “These measurements were able to probe thin vertical slices of Jupiter’s atmosphere,” said co-author Amy Simon, a Goddard scientist who specializes in planetary atmospheres. “Previous data sets had lower resolution, so the signals were essentially smeared out over a large section of the atmosphere.”

    The team found that the equatorial jet extends quite high into Jupiter’s stratosphere. Because the measurements covered such a large region, the researchers could eliminate several kinds of atmospheric waves from being major contributors to the QQO, leaving gravity waves as the primary driver. Their model assumes gravity waves are produced by convection in the lower atmosphere and travel up into the stratosphere, where they force the QQO to change direction.

    The results of simulations were an excellent match to the new set of observations, indicating that they correctly identified the mechanism. On Earth, gravity waves are considered most likely to be responsible for forcing the QBO to change direction, though they don’t appear to be strong enough to do the job alone.

    “Through this study we gained a better understanding of the physical mechanisms coupling the lower and upper atmosphere in Jupiter, and thus a better understanding of the atmosphere as a whole,” said Raúl Morales-Juberías, the second author on the paper and an associate professor at the New Mexico Institute of Mining and Technology in Socorro. “Despite the many differences between Earth and Jupiter, the coupling mechanisms between the lower and upper atmospheres in both planets are similar and have similar effects. Our model could be applied to study the effects of these mechanisms in other planets of the solar system and in exoplanets.”

    More information about Jupiter:

    http://www.nasa.gov/jupiter

    More information about NASA’s IRTF:

    http://irtfweb.ifa.hawaii.edu/

    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

     
  • richardmitnick 11:29 am on December 17, 2017 Permalink | Reply
    Tags: , , , , NASA Goddard, Spanning Disciplines in the Search for Life Beyond Earth   

    From Goddard: “Spanning Disciplines in the Search for Life Beyond Earth” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Dec. 13, 2017

    Lina Tran
    lina.tran@nasa.gov

    Karen Fox, Elizabeth Zubritsky, Carol Rasmussen
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    7
    An illustration of Kepler-186f, the first Earth-size planet discovered within a star’s habitable zone. Scientists now know of thousands of exoplanets, but our knowledge is limited because we can’t yet view them directly. Credit: NASA Ames/SETI Institute/JPL-Caltech

    Download related briefing materials from Dec. 13’s press conference at the 2017 American Geophysical Union meeting.

    The search for life beyond Earth is riding a surge of creativity and innovation. Following a gold rush of exoplanet discovery over the past two decades, it is time to tackle the next step: determining which of the known exoplanets are proper candidates for life.

    NASA/Kepler Telescope

    Scientists from NASA and two universities presented new results dedicated to this task in fields spanning astrophysics, Earth science, heliophysics and planetary science — demonstrating how a cross-disciplinary approach is essential to finding life on other worlds — at the fall meeting of the American Geophysical Union on Dec. 13, 2017, in New Orleans, Louisiana.

    “The potentially habitable real estate in the universe has greatly expanded,” said Giada Arney, an astrobiologist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We now know of thousands of exoplanets, but what we know about them is limited because we can’t yet see them directly.”

    Currently, scientists mostly rely on indirect methods to identify and study exoplanets; such methods can tell them whether a planet is Earth-like or how close it is to its parent star. But this isn’t yet enough to say whether a planet is truly habitable, or suitable for life — for this, scientists must ultimately be able to observe exoplanets directly.

    Direct-imaging instrument and mission designs are underway, but in the meantime, Arney explained, scientists are making progress with tools already at their disposal. They are building computational models to simulate what habitable planets might look like and how they would interact with their parent stars. To validate their models, they are looking to planets within our own solar system, as analogs for the exoplanets we may one day discover. This, of course, includes Earth itself — the planet we know best, and the only one we know of yet that is habitable.

    “In our quest for life on other worlds, it is important for scientists to consider exoplanets from a holistic sense — that is, from the perspective of multiple disciplines,” Arney said. “We need these multi-disciplinary studies to examine exoplanets as the complex worlds shaped by multiple astrophysical, planetary and stellar processes, rather than just distant points in the sky.”

    Studying Earth as an Exoplanet

    When humans start collecting the first direct images of exoplanets, even the closest image will appear as a handful of pixels. What can we learn about planetary life from just a smattering of pixels?

    Stephen Kane, an exoplanets expert at the University of California, Riverside, has come up with one way to answer that question using NASA’s Earth Polychromatic Imaging Camera aboard the National Oceanic and Atmospheric Administration’s Deep Space Climate Observatory, or DSCOVR.

    NASA EPIC (Earth Polychromatic Imaging Camera) on NOAA DSCOVR (Deep Space Climate Observatory)

    3
    EPIC schematic

    NOAA DISCOVR Deep Space Climate Observatory

    Kane explained that he and his colleagues take DSCOVR’s high-resolution images — typically used to document Earth’s global weather patterns and other climate-related events — and degrade them down to images just a few pixels in size. Kane runs the DSCOVR images through a noise filter that attempts to simulate the interference expected from an exoplanet mission.

    “From just a handful of pixels, we try to extract as much information that we know about Earth as we can,” Kane said. “If we can do it accurately for Earth, we can do this for planets around other stars.”

    3
    Left, an image of Earth from the DSCOVR-EPIC camera. Right, the same image degraded to a resolution of 3-by-3 pixels, similar to what researchers will see in future exoplanet observations.
    Credits: NOAA/NASA/DSCOVR

    DSCOVR takes a picture every half hour and it’s been in orbit for two years. Its more than 30,000 images are by far the longest continuous record of full-disk observations from space in existence. By observing how the brightness of Earth changes when mostly land is in view compared with mostly water, Kane has been able to reverse-engineer Earth’s albedo, obliquity, rotation rate and even seasonal variation — something that has yet to be measured directly for exoplanets — all of which could potentially influence a planet’s ability to support life.

    Searching for Other Venuses

    Much the way scientists use Earth as a case-study for habitable planets, they also use planets within the solar system — and therefore planets they are more familiar with — as studies for what makes planets uninhabitable.

    Kane also studies Earth’s sister planet, Venus, where the surface is 850 degrees Fahrenheit and the atmosphere — filled with sulfuric acid — bogs down on the surface with 90 times the pressure of Earth’s. Since Earth and Venus are so close in size and yet so different in terms of their prospects for habitability, he is interested in developing methods for distinguishing Earth- and Venus-analogs in other planetary systems, as a way of identifying potentially habitable terrestrial planets.

    Kane explained that he works to identify Venus analogs in data from NASA’s Kepler by defining the “Venus Zone,” where planetary insolation — how much light a given planet receives from its host star — plays a key role in atmospheric erosion and greenhouse gas cycles.

    “The fate of Earth and Venus and their atmospheres are tied to each other,” Kane said. “By searching for similar planets, we are trying to understand their evolution, and ultimately how often developing planets end up a Venus-like hellscape.”

    4
    Since Earth, right, and Venus, left, are so close in size and yet so different in terms of their prospects for habitability, Stephen Kane, an exoplanets expert at the University of California, Riverside, is interested in developing methods for distinguishing Earth- and Venus-analogs in other planetary systems, as a way of identifying potentially habitable terrestrial planets.
    Credits: NASA/JPL-Caltech/Ames

    Modeling Star-Planet Interactions

    While Kane talked about planets, Goddard space scientist Katherine Garcia-Sage focused on the way planets interact with their host star. Scientists must also consider how the qualities of a host star and a planet’s electromagnetic environment — which can shield it from harsh stellar radiation — either hinder or help habitability. Earth’s magnetic field, for example, protects the atmosphere from the harsh solar wind, the Sun’s constant outpouring of charged solar material, which can strip away atmospheric gases in a process called ionospheric escape.

    Garcia-Sage described research on Proxima b, an exoplanet that is four light-years away and known to exist within the habitable zone of its red dwarf star, Proxima Centauri. But just because it’s in the habitable zone — the right distance from a star where water could pool on a planet’s surface — doesn’t necessarily mean it’s habitable.

    Centauris Alpha Beta Proxima 27, February 2012. Skatebiker

    ESO/HARPS at La Silla

    ESO 3.6m telescope & HARPS at LaSilla, 600 km north of Santiago de Chile at an altitude of 2400 metres, which made the Proxima discovery

    While scientists can’t yet tell whether Proxima b is magnetized, they can use computational models to simulate how well an Earth-like magnetic field would protect its atmosphere at the exoplanet’s close orbit to Proxima Centauri, which frequently produces violent stellar storms. The effects of such storms on a given planet’s space environment are collectively known as space weather.

    “We need to understand a planet’s space weather environment to understand whether a planet is habitable,” Garcia-Sage said. “If the star is too active, it can endanger an atmosphere, which is necessary for providing liquid water. But there’s a fine line: There is some indication that radiation from a star can produce building blocks for life.”

    A red dwarf star — one of the most common types of stars in our galaxy — like Proxima Centauri strips away atmosphere when extreme ultraviolet radiation ionizes atmospheric gases, producing a swath of electrically charged particles that can stream out into space along magnetic field lines.

    5
    In this illustration, extreme ultraviolet light from an active red dwarf star cause ions to escape from an exoplanet’s atmosphere. Credits: NASA’s Goddard Space Flight Center

    The scientists calculated how much radiation Proxima Centauri produces on average, based on observations from NASA’s Chandra X-ray Observatory.

    NASA/Chandra Telescope

    At Proxima b’s orbit, the scientists found their Earth-like planet encountered bouts of extreme ultraviolet radiation hundreds of times greater than Earth does from the Sun.

    Garcia-Sage and her colleagues designed a computer model to study whether an Earth-like planet — with Earth’s atmosphere, magnetic field and gravity — in Proxima b’s orbit could hold on to its atmosphere. They examined three factors that drive ionospheric escape: stellar radiation, temperature of the neutral atmosphere, and size of the polar cap, the region over which the escape happens.

    The scientists show that with the extreme conditions likely to exist at Proxima b, the planet could lose an amount equivalent to the entirety of Earth’s atmosphere in 100 million years — just a fraction of Proxima b’s 4 billion years thus far. Even in the best-case scenario, that much mass escapes over 2 billion years, well within the planet’s lifetime.

    Mars, a Laboratory for Studying Exoplanets

    While Garcia-Sage spoke of magnetized planets, David Brain, planetary scientist at the University of Colorado, Boulder, spoke of Mars — a planet without a magnetic field.

    “Mars is a great laboratory for thinking about exoplanets,” Brain said. “We can use Mars to help constrain our thinking about a variety of rocky exoplanets where we don’t have observations yet.”

    Brain’s research uses observations from NASA’s Mars Atmosphere and Volatile Evolution, or MAVEN, mission to ask the question: How would Mars have evolved if it were orbiting a different kind of star? The answer provides information for how rocky planets — not unlike our own — could develop differently in different situations.


    NASA/Mars MAVEN

    It is thought that Mars once carried water and an atmosphere that might have made it hospitable to Earth-like life. But Mars lost much of its atmosphere over time through a variety of chemical and physical processes — MAVEN has observed similar atmospheric loss on the planet since its launch in late 2013.

    Brain, a MAVEN co-investigator, and his colleagues applied MAVEN’s insights to a hypothetical simulation of a Mars-like planet orbiting an M-class star — commonly known as a red dwarf star. In this imaginary situation, the planet would receive about five to 10 times more ultraviolet radiation than the real Mars does, which in turn speeds up atmospheric escape to much higher rates. Their calculations indicate that the planet’s atmosphere could lose three to five times as many charged particles and about five to 10 times more neutral particles.

    Such a rate of atmospheric loss suggests that orbiting at the edge of the habitable zone of a quiet M-class star, instead of our Sun, could shorten the habitable period for the planet by a factor of about five to 20.

    6
    To receive the same amount of starlight as Mars receives from our Sun, a planet orbiting an M-type red dwarf would have to be positioned much closer to its star than Mercury is to the Sun.
    Credits: NASA’s Goddard Space Flight Center

    “But I wouldn’t give up hope for rocky planets orbiting M dwarfs,” Brain said. “We picked a worst-case scenario. Mars is a small planet, and lacks a magnetic field so solar wind can more effectively strip away its atmosphere. We also picked a Mars that isn’t geologically active, so there’s no internal source of atmosphere. If you changed any one factor, such a planet might be a happier place.”

    Each one of these studies contributes just one piece to a much larger puzzle — to determine what characteristics we should look for, and need to recognize, in the search for a planet that might support life. Together, such interdisciplinary research lays the groundwork to ensure that, as new missions to observe exoplanets more clearly are developed, we’ll be ready to determine if they might just host life.

    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

     
  • richardmitnick 5:34 pm on December 10, 2017 Permalink | Reply
    Tags: , , , , , , , NASA Goddard, NASA's SuperTIGER Balloon Flies Again to Study Heavy Cosmic Particles, ,   

    From Goddard: “NASA’s SuperTIGER Balloon Flies Again to Study Heavy Cosmic Particles” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Dec. 6, 2017
    Francis Reddy
    francis.j.reddy@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    A science team in Antarctica is preparing to loft a balloon-borne instrument to collect information on cosmic rays, high-energy particles from beyond the solar system that enter Earth’s atmosphere every moment of every day. The instrument, called the Super Trans-Iron Galactic Element Recorder (SuperTIGER), is designed to study rare heavy nuclei, which hold clues about where and how cosmic rays attain speeds up to nearly the speed of light.

    1
    NASA’s Super-TIGER balloon

    The launch is expected by Dec. 10, weather permitting.

    1
    Explore this infographic [on the full article] to learn more about SuperTIGER, cosmic rays and scientific ballooning.
    Credits: NASA’s Goddard Space Flight Center

    Download infographic as PDF

    “The previous flight of SuperTIGER lasted 55 days, setting a record for the longest flight of any heavy-lift scientific balloon,” said Robert Binns, the principal investigator at Washington University in St. Louis, which leads the mission. “The time aloft translated into a long exposure, which is important because the particles we’re after make up only a tiny fraction of cosmic rays.”

    The most common cosmic ray particles are protons or hydrogen nuclei, making up roughly 90 percent, followed by helium nuclei (8 percent) and electrons (1 percent). The remainder contains the nuclei of other elements, with dwindling numbers of heavy nuclei as their mass rises. With SuperTIGER, researchers are looking for the rarest of the rare — so-called ultra-heavy cosmic ray nuclei beyond iron, from cobalt to barium.

    “Heavy elements, like the gold in your jewelry, are produced through special processes in stars, and SuperTIGER aims to help us understand how and where this happens,” said lead co-investigator John Mitchell at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We’re all stardust, but figuring out where and how this stardust is made helps us better understand our galaxy and our place in it.”

    When a cosmic ray strikes the nucleus of a molecule of atmospheric gas, both explode in a shower of subatomic shrapnel that triggers a cascade of particle collisions. Some of these secondary particles reach detectors on the ground, providing information scientists can use to infer the properties of the original cosmic ray. But they also produce an interfering background that is greatly reduced by flying instruments on scientific balloons, which reach altitudes of nearly 130,000 feet (40,000 meters) and float above 99.5 percent of the atmosphere.

    The most massive stars forge elements up to iron in their cores and then explode as supernovas, dispersing the material into space. The explosions also create conditions that result in a brief, intense flood of subatomic particles called neutrons. Many of these neutrons can “stick” to iron nuclei. Some of them subsequently decay into protons, producing new elements heavier than iron.

    Supernova blast waves provide the boost that turns these particles into high-energy cosmic rays.

    4
    NASA’s Fermi Proves Supernova Remnants Produce Cosmic Rays. February 14, 2013.

    NASA/Fermi Telescope


    NASA/Fermi LAT


    As a shock wave expands into space, it entraps and accelerates particles until they reach energies so extreme they can no longer be contained.

    4
    On Dec. 1, SuperTIGER was brought onto the deck of Payload Building 2 at McMurdo Station, Antarctica, to test communications in preparation for its second flight. Mount Erebus, the southernmost active volcano on Earth, appears in the background.
    Credits: NASA/Jason Link

    Over the past two decades, evidence accumulated from detectors on NASA’s Advanced Composition Explorer satellite and SuperTIGER’s predecessor, the balloon-borne TIGER instrument, has allowed scientists to work out a general picture of cosmic ray sources. Roughly 20 percent of cosmic rays were thought to arise from massive stars and supernova debris, while 80 percent came from interstellar dust and gas with chemical quantities similar to what’s found in the solar system.

    “Within the last few years, it has become apparent that some or all of the very neutron-rich elements heavier than iron may be produced by neutron star mergers instead of supernovas,” said co-investigator Jason Link at Goddard.

    Neutron stars are the densest objects scientists can study directly, the crushed cores of massive stars that exploded as supernovas. Neutron stars orbiting each other in binary systems emit gravitational waves, which are ripples in space-time predicted by Einstein’s general theory of relativity. These waves remove orbital energy, causing the stars to draw ever closer until they eventually crash together and merge.

    Theorists calculated that these events would be so thick with neutrons they could be responsible for most of the very neutron-rich cosmic rays heavier than nickel. On Aug. 17, NASA’s Fermi Gamma-ray Space Telescope and the National Science Foundation’s Laser Interferometer Gravitational-wave Observatory detected the first light and gravitational waves from crashing neutron stars. Later observations by the Hubble and Spitzer space telescopes indicate that large amounts of heavy elements were formed in the event.

    “It’s possible neutron star mergers are the dominant source of heavy, neutron-rich cosmic rays, but different theoretical models produce different quantities of elements and their isotopes,” Binns said. “The only way to choose between them is to measure what’s really out there, and that’s what we’ll be doing with SuperTIGER.”

    SuperTIGER is funded by the NASA Headquarters Science Mission Directorate Astrophysics Division.

    The National Science Foundation (NSF) Office of Polar Programs manages the U.S. Antarctic Program and provides logistic support for all U.S. scientific operations in Antarctica. NSF’s Antarctic support contractor supports the launch and recovery operations for NASA’s Balloon Program in Antarctica. Mission data were downloaded using NASA’s Tracking and Data Relay Satellite System.

    For more information about NASA’s Balloon Program, visit:

    http://www.nasa.gov/balloons

    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

     
  • richardmitnick 10:56 am on November 22, 2017 Permalink | Reply
    Tags: , , , Comet 45P/Honda-Mrkos-Pajdušáková, , NASA Goddard,   

    From Goddard: “NASA Telescope Studies Quirky Comet 45P” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Nov. 21, 2017
    Elizabeth Zubritsky
    elizabeth.a.zubritsky@nasa.gov
    NASA’s Goddard Space Flight Center in Greenbelt, Md.

    When comet 45P zipped past Earth early in 2017, researchers observing from NASA’s Infrared Telescope Facility, or IRTF, in Hawai’i gave the long-time trekker a thorough astronomical checkup. The results help fill in crucial details about ices in Jupiter-family comets and reveal that quirky 45P doesn’t quite match any comet studied so far.

    Like a doctor recording vital signs, the team measured the levels of nine gases released from the icy nucleus into the comet’s thin atmosphere, or coma. Several of these gases supply building blocks for amino acids, sugars and other biologically relevant molecules. Of particular interest were carbon monoxide and methane, which are so hard to detect in Jupiter-family comets that they’ve only been studied a few times before.

    1
    Comet 45P/Honda-Mrkos-Pajdušáková is captured using a telescope on December 22 from Farm Tivoli in Namibia, Africa.
    Credits: Gerald Rhemann

    The gases all originate from the hodgepodge of ices, rock and dust that make up the nucleus. These native ices are thought to hold clues to the comet’s history and how it has been aging.

    “Comets retain a record of conditions from the early solar system, but astronomers think some comets might preserve that history more completely than others,” said Michael DiSanti, an astronomer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the new study in The Astronomical Journal.

    The comet—officially named 45P/Honda-Mrkos-Pajdušáková—belongs to the Jupiter family of comets, frequent orbiters that loop around the Sun about every five to seven years. Much less is known about native ices in this group than in the long-haul comets from the Oort Cloud.

    To identify native ices, astronomers look for chemical fingerprints in the infrared part of the spectrum, beyond visible light. DiSanti and colleagues conducted their studies using the iSHELL high-resolution spectrograph recently installed at IRTF on the summit of Maunakea.

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA, 4,207 m (13,802 ft) above sea level

    With iSHELL, researchers can observe many comets that used to be considered too faint.

    The spectral range of the instrument makes it possible to detect many vaporized ices at once, which reduces the uncertainty when comparing the amounts of different ices. The instrument covers wavelengths starting at 1.1 micrometers in the near-infrared (the range of night-vision goggles) up to 5.3 micrometers in the mid-infrared region.

    iSHELL also has high enough resolving power to separate infrared fingerprints that fall close together in wavelength. This is particularly necessary in the cases of carbon monoxide and methane, because their fingerprints in comets tend to overlap with the same molecules in Earth’s atmosphere.

    “The combination of iSHELL’s high resolution and the ability to observe in the daytime at IRTF is ideal for studying comets, especially short-period comets,” said John Rayner, director of the IRTF, which is managed for NASA by the University of Hawai’i.

    While observing for two days in early January 2017—shortly after 45P’s closest approach to the Sun—the team made robust measurements of water, carbon monoxide, methane and six other native ices. For five ices, including carbon monoxide and methane, the researchers compared levels on the sun-drenched side of the comet to the shaded side. The findings helped fill in some gaps but also raised new questions.

    The results reveal that 45P is running so low on frozen carbon monoxide, that it is officially considered depleted. By itself, this wouldn’t be too surprising, because carbon monoxide escapes into space easily when the Sun warms a comet. But methane is almost as likely to escape, so an object lacking carbon monoxide should have little methane. 45P, however, is rich in methane and is one of the rare comets that contains more methane than carbon monoxide ice.

    It’s possible that the methane is trapped inside other ice, making it more likely to stick around. But the researchers think the carbon monoxide might have reacted with hydrogen to form methanol. The team found that 45P has a larger-than-average share of frozen methanol.

    When this reaction took place is another question—one that gets to the heart of comet science. If the methanol was produced on grains of primordial ice before 45P formed, then the comet has always been this way. On the other hand, the levels of carbon monoxide and methanol in the coma might have changed over time, especially because Jupiter-family comets spend more time near the Sun than Oort Cloud comets do.

    “Comet scientists are like archaeologists, studying old samples to understand the past,” said Boncho Bonev, an astronomer at American University and the second author on the paper. “We want to distinguish comets as they formed from the processing they might have experienced, like separating historical relics from later contamination.”

    The team is now on the case to figure out how typical their results might be among similar comets. 45P was the first of five such short-period comets that are available for study in 2017 and 2018. On the heels of 45P were comets 2P/Encke and 41P/Tuttle-Giacobini-Kresak. Due next summer and fall is 21P/Giacobini–Zinner, and later will come 46P/Wirtanen, which is expected to remain within 10 million miles (16 million kilometers) of Earth throughout most of December 2018.

    “This research is groundbreaking,” said Faith Vilas, the solar and planetary research program director at the National Science Foundation, or NSF, which helped support the study. “This broadens our knowledge of the mix of molecular species coexisting in the nuclei of Jovian-family comets, and the differences that exist after many trips around the Sun.”

    “We’re excited to see this first publication from iSHELL, which was built through a partnership between NSF, the University of Hawai’i, and NASA,” said Kelly Fast, IRTF program scientist at NASA Headquarters. “This is just the first of many iSHELL results to come.”

    More information about NASA’s IRTF:
    http://irtfweb.ifa.hawaii.edu/

    More information about comets:
    http://www.nasa.gov/comets

    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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