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  • richardmitnick 3:55 pm on June 25, 2017 Permalink | Reply
    Tags: , , , , Interstellar medium, NASA CHESS - Colorado High-resolution Echelle Stellar Spectrograph, NASA Goddard,   

    From Goddard: “NASA-Funded CHESS Mission Will Check Out the Space Between Stars” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    June 23, 2017
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Deep in space between distant stars, space is not empty. Instead, there drifts vast clouds of neutral atoms and molecules, as well as charged plasma particles called the interstellar medium — that may, over millions of years, evolve into new stars and even planets. These floating interstellar reservoirs are the focus of the NASA-funded CHESS sounding rocket mission, which will check out the earliest stages of star formation.

    CHESS — short for the Colorado High-resolution Echelle Stellar Spectrograph — is a sounding rocket payload that will fly on a Black Brant IX suborbital sounding rocket early in the morning of June 27, 2017. CHESS measures light filtering through the interstellar medium to study the atoms and molecules within, which provides crucial information for understanding the lifecycle of stars.

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    Floating clouds of the interstellar medium are the focus of the NASA-funded CHESS sounding rocket mission, which will check out the earliest stages of star formation. Here, the CHESS payload is integrated with the sounding rocket before launch.
    Credits: photo courtesy of Kevin France

    [NO IMAGES OF CHESS SATELLITE AVAILABLE]

    “The interstellar medium pervades the galaxy,” said Kevin France, the CHESS principle investigator at the University of Colorado, Boulder.

    “When massive stars explode as supernovae, they expel this raw material. It’s the insides of dead stars, turning into the next generation of stars and planets.”

    CHESS is a spectrograph, which provides information on how much of any given wavelength of light is present. It will train its eye at Beta Scorpii — a hot, brightly shining star in the Scorpius constellation well-positioned for the instrument to probe the material between the star and our own solar system. As light from Beta Scorpii streams toward Earth, atoms and molecules — including carbon, oxygen and hydrogen — block the light to varying degrees along the way.

    Scientists know which wavelengths are blocked by what, so by looking at how much light reaches the space around Earth, they can assess all sorts of details about the space it travelled through to get there. CHESS data provides observations such as which atoms and molecules are present in space, their temperatures and how fast they’re moving.

    The scientists also use CHESS data to evaluate how the interstellar cloud is structured, which can help them pinpoint where it stands in the process of star formation. It’s still not known exactly how long it takes for this material to be incorporated into new stars. But scientists know dense clouds can pave the way for the collapse at the very beginning of star formation.

    The flight of a sounding rocket is a short one; CHESS will fly for about 16 minutes total. Just six-and-a-half of those minutes are spent making observations between 90 and 200 miles above the surface — observations that can only be made in space, above the atmosphere, which the far-ultraviolet light that CHESS observes can’t penetrate. After the flight, the payload parachutes to the ground, where it can be recovered for future flights.

    This is the third flight for the CHESS payload in the past three years, and the mission’s most detailed survey yet. The scientists have used each to trial and improve the technology; the upcoming flight sports an upgraded diffraction grating, which reflects light and separates it into its different wavelengths.

    “A more efficient grating means the instrument is that many times more sensitive,” France said. “Compared to the first flight of CHESS, this third incarnation is about eight times more sensitive.”

    By flying rapidly developing instruments on relatively inexpensive sounding rockets, scientists are not only able to acquire high-quality science data, but also test and mature their instruments toward possible spaceflight. According to France, the CHESS instrument serves as a spectrograph prototype for NASA’s LUVOIR concept.

    “Supporting technology and suborbital flight projects today directly translates into lower risk and shorter development time for NASA’s large missions in the next two decades,” France said.

    The launch window for CHESS opens at 1:10 a.m. EDT at the White Sands Missile Range near Las Cruces, New Mexico. Precise timing of the launch will depend on weather conditions.

    CHESS is supported through NASA’s Sounding Rocket Program conducted at the agency’s Wallops Flight Facility, which is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Orbital ATK provides mission planning, engineering services and field operations for the NASA Sounding Rocket Operations Contract. NASA’s Heliophysics Division manages the sounding rocket program for the agency.

    Related:

    More about NASA’s sounding rocket program
    Voyager 1 Helps Solver Interstellar Medium Mystery
    NASA’s IBEX Provides First View of the Solar System’s Tail

    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 4:39 pm on June 23, 2017 Permalink | Reply
    Tags: , , , NASA Goddard, NASA/DLR Grace   

    From Goddard: “ESA to Develop Gravitational Wave Space Mission with NASA Support” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    June 22, 2017
    Francis Reddy
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    ESA (the European Space Agency) has selected the Laser Interferometer Space Antenna (LISA) for its third large-class mission in the agency’s Cosmic Vision science program. The three-spacecraft constellation is designed to study gravitational waves in space and is a concept long studied by both ESA and NASA.

    ESA’s Science Program Committee announced the selection at a meeting on June 20. The mission will now be designed, budgeted and proposed for adoption before construction begins. LISA is expected to launch in 2034. NASA will be a partner with ESA in the design, development, operations and data analysis of the mission.

    ESA/eLISA the future of gravitational wave research

    Gravitational radiation was predicted a century ago by Albert Einstein’s general theory of relativity. Massive accelerating objects such as merging black holes produce waves of energy that ripple through the fabric of space and time. Indirect proof of the existence of these waves came in 1978, when subtle changes observed in the motion of a pair of orbiting neutron stars showed energy was leaving the system in an amount matching predictions of energy carried away by gravitational waves.

    In September 2015, these waves were first directly detected by the National Science Foundation’s ground-based Laser Interferometer Gravitational-Wave Observatory (LIGO).


    Caltech/MIT Advanced aLigo Hanford, WA, USA installation


    Caltech/MIT Advanced aLigo detector installation Livingston, LA, USA

    Cornell SXS, the Simulating eXtreme Spacetimes (SXS) project


    Gravitational waves. Credit: MPI for Gravitational Physics/W.Benger-Zib

    ESA/eLISA the future of gravitational wave research

    The signal arose from the merger of two stellar-mass black holes located some 1.3 billion light-years away. Similar signals from other black hole mergers have since been detected.

    Seismic, thermal and other noise sources limit LIGO to higher-frequency gravitational waves around 100 cycles per second (hertz). But finding signals from more powerful events, such as mergers of supermassive black holes in colliding galaxies, requires the ability to detect frequencies much lower than 1 hertz, a sensitivity level only possible from space.

    LISA consists of three spacecraft separated by 1.6 million miles (2.5 million kilometers) in a triangular formation that follows Earth in its orbit around the sun. Each spacecraft carries test masses that are shielded in such a way that the only force they respond to is gravity. Lasers measure the distances to test masses in all three spacecraft. Tiny changes in the lengths of each two-spacecraft arm signals the passage of gravitational waves through the formation.

    For example, LISA will be sensitive to gravitational waves produced by mergers of supermassive black holes, each with millions or more times the mass of the sun. It will also be able to detect gravitational waves emanating from binary systems containing neutron stars or black holes, causing their orbits to shrink. And LISA may detect a background of gravitational waves produced during the universe’s earliest moments.

    For decades, NASA has worked to develop many technologies needed for LISA, including measurement, micropropulsion and control systems, as well as support for the development of data analysis techniques.

    For instance, the GRACE Follow-On mission, a U.S. and German collaboration to replace the aging GRACE satellites scheduled for launch late this year, will carry a laser measuring system that inherits some of the technologies originally developed for LISA.

    NASA/DLR Grace

    The mission’s Laser Ranging Interferometer will track distance changes between the two satellites with unprecedented precision, providing the first demonstration of the technology in space.

    In 2016, ESA’s LISA Pathfinder successfully demonstrated key technologies needed to build LISA.

    ESA/LISA Pathfinder

    Each of LISA’s three spacecraft must gently fly around its test masses without disturbing them, a process called drag-free flight. In its first two months of operations, LISA Pathfinder demonstrated this process with a precision some five times better than its mission requirements and later reached the sensitivity needed for the full multi-spacecraft observatory. U.S. researchers collaborated on aspects of LISA Pathfinder for years, and the mission carries a NASA-supplied experiment called the ST7 Disturbance Reduction System, which is managed by NASA’s Jet Propulsion Laboratory in Pasadena, California.

    For more information about the LISA project, visit:

    https://lisa.nasa.gov

    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 9:06 am on June 23, 2017 Permalink | Reply
    Tags: NASA Goddard, , Scientists Uncover Origins of the Sun’s Swirling Spicules, , Swedish 1-meter Solar Telescope in La Palma Spain   

    From Goddard: “Scientists Uncover Origins of the Sun’s Swirling Spicules” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    June 22, 2017
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    1
    No image caption or credit.

    At any given moment, as many as 10 million wild jets of solar material burst from the sun’s surface. They erupt as fast as 60 miles per second, and can reach lengths of 6,000 miles before collapsing. These are spicules, and despite their grass-like abundance, scientists didn’t understand how they form. Now, for the first time, a computer simulation — so detailed it took a full year to run — shows how spicules form, helping scientists understand how spicules can break free of the sun’s surface and surge upward so quickly.

    This work relied upon high-cadence observations from NASA’s Interface Region Imaging Spectrograph, or IRIS, and the Swedish 1-meter Solar Telescope in La Palma, in the Canary Islands. Together, the spacecraft and telescope peer into the lower layers of the sun’s atmosphere, known as the interface region, where spicules form. The results of this NASA-funded study were published in Science on June 22, 2017 — a special time of the year for the IRIS mission, which celebrates its fourth anniversary in space on June 26.

    NASA IRIS spacecraft

    2
    Swedish 1-meter Solar Telescope in La Palma, in the Canary Islands, Spain


    Watch the video to learn how scientists used a combination of computer simulations and observations to determine how spicules form.
    Credits: NASA’s Goddard Space Flight Center/Joy Ng, producer

    “Numerical models and observations go hand in hand in our research,” said Bart De Pontieu, an author of the study and IRIS science lead at Lockheed Martin Solar and Astrophysics Laboratory, in Palo Alto, California. “We compare observations and models to figure out how well our models are performing, and to improve the models when we see major discrepancies.”

    Observing spicules has been a thorny problem for scientists who want to understand how solar material and energy move through and away from the sun. Spicules are transient, forming and collapsing over the course of just five to 10 minutes. These tenuous structures are also difficult to study from Earth, where the atmosphere often blurs our telescopes’ vision.

    A team of scientists has been working on this particular model for nearly a decade, trying again and again to create a version that would create spicules. Earlier versions of the model treated the interface region, the lower solar atmosphere, as a hot gas of electrically charged particles — or more technically, a fully ionized plasma. But the scientists knew something was missing because they never saw spicules in the simulations.

    The key, the scientists realized, was neutral particles. They were inspired by Earth’s own ionosphere, a region of the upper atmosphere where interactions between neutral and charged particles are responsible for many dynamic processes.

    The research team knew that in cooler regions of the sun, such as the interface region, not all gas particles are electrically charged. Some particles are neutral, and neutral particles aren’t subject to magnetic fields like charged particles are. Scientists had based previous models on a fully ionized plasma in order to simplify the problem. Indeed, including the necessary neutral particles was very computationally expensive, and the final model took roughly a year to run on the Pleiades supercomputer located at NASA’s Ames Research Center in Silicon Valley, and which supports hundreds of science and engineering projects for NASA missions.

    The model began with a basic understanding of how plasma moves in the sun’s atmosphere. Constant convection, or boiling, of material throughout the sun generates islands of tangled magnetic fields. When boiling carries them up to the surface and farther into the sun’s lower atmosphere, magnetic field lines rapidly snap back into place to resolve the tension, expelling plasma and energy. Out of this violence, a spicule is born. But explaining how these complex magnetic knots rise and snap was the tricky part.

    “Usually magnetic fields are tightly coupled to charged particles,” said Juan Martínez-Sykora, lead author of the study and a solar physicist at Lockheed Martin and the Bay Area Environmental Research Institute in Sonoma, California. “With only charged particles in the model, the magnetic fields were stuck, and couldn’t rise beyond the sun’s surface. When we added neutrals, the magnetic fields could move more freely.”

    Neutral particles provide the buoyancy the gnarled knots of magnetic energy need to rise through the sun’s boiling plasma and reach the chromosphere. There, they snap into spicules, releasing both plasma and energy. Friction between ions and neutral particles heats the plasma even more, both in and around the spicules.

    With the new model, the simulations at last matched observations from IRIS and the Swedish Solar Telescope; spicules occurred naturally and frequently. The 10 years of work that went into developing this numerical model earned scientists Mats Carlsson and Viggo H. Hansteen, both authors of the study from the University of Oslo in Norway, the 2017 Arctowski Medal from the National Academy of Sciences. Martínez-Sykora led the expansion of the model to include the effects of neutral particles.

    The scientists’ updated model revealed something else about how energy moves in the solar atmosphere. It turns out this whip-like process also naturally generates Alfvén waves, a strong kind of magnetic wave scientists suspect is key to heating the sun’s atmosphere and propelling the solar wind, which constantly bathes our solar system and planet with charged particles from the sun.

    “This model answers a lot of questions we’ve had for so many years,” De Pontieu said. “We gradually increased the physical complexity of numerical models based on high-resolution observations, and it is really a success story for the approach we’ve taken with IRIS.”

    The simulations indicate spicules could play a big role in energizing the sun’s atmosphere, by constantly forcing plasma out and generating so many Alfvén waves across the sun’s entire surface.

    “This is a major advance in our understanding of what processes can energize the solar atmosphere, and lays the foundation for investigations with even more detail to determine how big of a role spicules play,” said Adrian Daw, IRIS mission scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “A very nice result on the eve of our launch anniversary.”

    Related:

    IRIS Mission Overview
    New Space Weather Model Helps Simulate Magnetic Structure of Solar Storms

    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 7:56 am on June 12, 2017 Permalink | Reply
    Tags: , , , , Deep Extragalactic Evolutionary Probe 2 (DEEP2) Redshift Survey, NASA Goddard   

    From Goddard: “Astronomers Uncover A Surprising Trend in Galaxy Evolution” 2012 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    Oct. 19, 2012
    Francis Reddy
    NASA’s Goddard Space Flight Center

    Last Updated: Jan. 17, 2017
    Editor: Lynn Jenner


    A study of 544 star-forming galaxies observed by the Keck and Hubble telescopes shows that disk galaxies like our own Milky Way unexpectedly reached their current state long after much of the universe’s star formation had ceased. Over the past 8 billion years, the galaxies lose chaotic motions and spin faster as they develop into settled disk galaxies. Credits: NASA’s Goddard Space Flight Center.

    A comprehensive study of hundreds of galaxies observed by the Keck telescopes in Hawaii and NASA’s Hubble Space Telescope has revealed an unexpected pattern of change that extends back 8 billion years, or more than half the age of the universe.

    Keck Observatory, Mauna Kea, Hawaii, USA

    NASA/ESA Hubble Telescope

    “Astronomers thought disk galaxies in the nearby universe had settled into their present form by about 8 billion years ago, with little additional development since,” said Susan Kassin, an astronomer at NASA’s Goddard Space Flight Center in Greenbelt, Md., and the study’s lead researcher. “The trend we’ve observed instead shows the opposite, that galaxies were steadily changing over this time period.”

    Today, star-forming galaxies take the form of orderly disk-shaped systems, such as the Andromeda Galaxy or the Milky Way, where rotation dominates over other internal motions. The most distant blue galaxies in the study tend to be very different, exhibiting disorganized motions in multiple directions. There is a steady shift toward greater organization to the present time as the disorganized motions dissipate and rotation speeds increase. These galaxies are gradually settling into well-behaved disks.

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    This plot shows the fractions of settled disk galaxies in four time spans, each about 3 billion years long. There is a steady shift toward higher percentages of settled galaxies closer to the present time. At any given time, the most massive galaxies are the most settled. More distant and less massive galaxies on average exhibit more disorganized internal motions, with gas moving in multiple directions, and slower rotation speeds. Credit: NASA’s Goddard Space Flight Center.

    Blue galaxies – their color indicates stars are forming within them – show less disorganized motions and ever-faster rotation speeds the closer they are observed to the present. This trend holds true for galaxies of all masses, but the most massive systems always show the highest level of organization.

    Researchers say the distant blue galaxies they studied are gradually transforming into rotating disk galaxies like our own Milky Way.

    “Previous studies removed galaxies that did not look like the well-ordered rotating disks now common in the universe today,” said co-author Benjamin Weiner, an astronomer at the University of Arizona in Tucson. “By neglecting them, these studies examined only those rare galaxies in the distant universe that are well-behaved and concluded that galaxies didn’t change.”

    Rather than limit their sample to certain galaxy types, the researchers instead looked at all galaxies with emission lines bright enough to be used for determining internal motions. Emission lines are the discrete wavelengths of radiation characteristically emitted by the gas within a galaxy. They are revealed when a galaxy’s light is separated into its component colors. These emission lines also carry information about the galaxy’s internal motions and distance.


    Simulations such as this will help astronomers better understand the new findings in galaxy evolution. It tracks the development of a single disk galaxy from shortly after the Big Bang to the present day. Colors reveal old stars (red), young stars (white and bright blue) and the distribution of gas density (pale blue); the view is 300,000 light-years across.
    Credits: F. Governato and T. Quinn (Univ. of Washington), A. Brooks (Univ. of Wisconsin, Madison), and J. Wadsley (McMaster Univ.)

    The team studied a sample of 544 blue galaxies from the Deep Extragalactic Evolutionary Probe 2 (DEEP2) Redshift Survey, a project that employs Hubble and the twin 10-meter telescopes at the W. M. Keck Observatory in Hawaii. Located between 2 billion and 8 billion light-years away, the galaxies have stellar masses ranging from about 0.3 percent to 100 percent of the mass of our home galaxy.

    2
    While the Sloan Digital Sky Survey (left) looks at galaxies in the nearby universe, the DEEP2 Galaxy Redshift Survey is a smaller survey of much more distant galaxies. Their distance from us (7 billion light years or more) means that the light we see today left these galaxies when the universe was less than half as old as it is today, and is so faint that the world’s largest telescope, the Keck, is needed to study them. The magnified regions show that as the universe evolved, galaxies became more densely clustered even as these clusters moved farther apart with the expansion of the universe. The strength of these effects depends on cosmological parameters, allowing the study of dark energy by comparing groups and clusters of galaxies at low and high redshift. (Credit: Brian Gerke, UC Berkeley)

    Universe map Sloan Digital Sky Survey (SDSS) 2dF Galaxy Redshift Survey

    SDSS Telescope at Apache Point Observatory, NM, USA

    A paper describing these findings will be published Oct. 20 in The Astrophysical Journal.

    The Milky Way galaxy must have gone through the same rough-and-tumble evolution as the galaxies in the DEEP2 sample, and gradually settled into its present state as the sun and solar system were being formed.

    In the past 8 billion years, the number of mergers between galaxies large and small has decreased sharply. So has the overall rate of star formation and disruptions of supernova explosions associated with star formation. Scientists speculate these factors may play a role in creating the evolutionary trend they observe.

    Now that astronomers see this pattern, they can adjust computer simulations of galaxy evolution until these models are able to replicate the observed trend. This will guide scientists to the physical processes most responsible for it.

    The DEEP2 survey is led by Lick Observatory at the University of California at Santa Cruz in collaboration with the University of California at Berkeley, the University of Hawaii at Manoa, Johns Hopkins University in Baltimore, Md., the University of Chicago and the California Institute of Technology in Pasadena.

    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

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc. in Washington.

    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc. in Washington.

    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 1:27 pm on May 27, 2017 Permalink | Reply
    Tags: , , , , NASA Goddard, , , New NASA Mission to Study Mysterious Neutron Stars and Aid in Deep Space Navigation   

    From Goddard: “New NASA Mission to Study Mysterious Neutron Stars, Aid in Deep Space Navigation” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    May 26, 2017
    Claire Saravia
    claire.g.desaravia@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    A new NASA mission is headed for the International Space Station next month to observe one of the strangest observable objects in the universe.

    Launching June 1, the Neutron Star Interior Composition Explorer (NICER) will be installed aboard the space station as the first mission dedicated to studying neutron stars, a type of collapsed star that is so dense scientists are unsure how matter behaves deep inside it.

    NASA/NICER

    NASA NICER

    A neutron star begins its life as a star between about seven and 20 times the mass of our sun. When this type of star runs out of fuel, it collapses under its own weight, crushing its core and triggering a supernova explosion. What remains is an ultra-dense sphere only about 12 miles (20 kilometers) across, the size of a city, but with up to twice the mass of our sun squeezed inside. On Earth, one teaspoon of neutron star matter would weigh a billion tons.

    “If you took Mount Everest and squeezed it into something like a sugar cube, that’s the kind of density we’re talking about,” said Keith Gendreau, the principal investigator for NICER at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.


    Though we know neutron stars are small and extremely dense, there are still many aspects of these remnants of explosive deaths of other stars that we have yet to understand. NICER, a facility to be mounted on the outside of the International Space Station, seeks to find the answers to some of the questions still being asked about neutron stars. By capturing the arrival time and energy of the X-ray photons produced by pulsars emitted by neutron stars, NICER seeks to answer decades-old questions about extreme forms of matter and energy. Data from NICER will also be used in SEXTANT, an on-board demonstration of pulsar-based navigation. Credits: NASA’s Johnson Space Center

    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 9:37 pm on May 20, 2017 Permalink | Reply
    Tags: , , , Detecting sodium, , Earth's Mesosphere, Heliophysics Technology and Instrument Development for Science, Lidar instruments, NASA Goddard, World’s first space-based sodium lidar to study Earth’s poorly understood mesosphere   

    From Goddard: “NASA Aims to Create First-Ever Space-Based Sodium Lidar to Study Poorly Understood Mesosphere” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    [Dedicated to J.L.T. in the hope that he will keep Goddard and JHUAPL in view for his future.]

    May 16, 2017
    Lori Keesey
    NASA’s Goddard Space Flight Center

    1
    Mike Krainak (left) and Diego Janches recently won NASA follow-on funding to advance a spaceborne sodium lidar needed to probe Earth’s poorly understood mesosphere. Credits: NASA/W. Hrybyk

    A team of NASA scientists and engineers now believes it can leverage recent advances in a greenhouse-detecting instrument to build the world’s first space-based sodium lidar to study Earth’s poorly understood mesosphere.

    Scientist Diego Janches and laser experts Mike Krainak and Tony Yu, all of whom work at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are leading a research-and-development effort to further advance the sodium lidar, which the group plans to deploy on the International Space Station if it succeeds in proving its flightworthiness.

    NASA’s Center Innovation Fund and the Heliophysics Technology and Instrument Development for Science programs are now funding the instrument’s maturation. However, the concept traces its heritage in part to NASA’s past investments in promising lidar instruments, called Sounders, originally created to measure carbon dioxide and methane in Earth’s atmosphere.

    From its berth on the orbiting outpost, the instrument would illuminate the complex relationship between the chemistry and dynamics of the mesosphere that lies 40-100 miles above Earth’s surface — the region where Earth’s atmosphere meets the vacuum of space.

    Given the progress the researchers have made with the Earth-observing sounding instruments, coupled with Goddard’s legacy in laser technology, they are optimistic about the instrument’s ultimate success.

    2
    With NASA technology-development funding, a Goddard team of scientists and engineers will advance a sodium lidar instrument for use in space. This image shows the laboratory breadboard. Credits: NASA/W. Hrybyk

    The Big Leverage

    “What we’re doing is leveraging what we learned with the CO2 and Methane Sounders,” Krainak said. Both instruments have demonstrated in multiple aircraft campaigns that they accurately measure greenhouse gases using lidar.

    Lidar involves pulsing a laser light off Earth’s surface. Like all atmospheric gases, carbon dioxide and methane absorb the light in narrow wavelength bands. By tuning the laser across those absorption lines, scientists can detect and then analyze the level of gases in that vertical path. The more gas along the light’s path, the deeper the absorption lines.

    “The same principle applies here,” Janches said. “Instead of carbon dioxide and methane, we’re detecting sodium because of what it can tell us about the small-scale dynamics occurring in the mesosphere.”

    Sodium — the sixth most abundant element in Earth’s crust — is a useful tracer for characterizing the mesosphere. Though this atmospheric layer contains other granules of metals, including iron, magnesium, calcium, and potassium — all produced by the evaporation of extraterrestrial dust when it encounters Earth’s atmosphere — sodium is easiest to detect. Literally, a layer of sodium exists in the mesosphere.

    Because of its relative abundance, sodium provides higher-resolution data that can reveal more information about the small-scale dynamics occurring in the upper atmosphere. From this, scientists can learn more about how weather in the lower atmosphere influences the border between the atmosphere and space.

    The group has begun developing its instrument, which is electronically tuned to the 589-nanometer range, or yellow light. While in orbit, the lidar would rapidly pulse the light at the mesospheric layer, down one to three kilometers over a swath measuring four to eight kilometers in width.

    The light’s interaction with sodium particles would cause them to glow or resonate. By detecting the glow-back, the lidar’s onboard spectrometer would analyze the light to determine how much sodium resided in the mesosphere, its temperature, and the speed at which the particles were moving.

    Scientists have used sodium lidars in ground-based measurements for at least four decades, but they never have gathered measurements from space. As a result, the data is limited in time and space and does not offer a global picture of the dynamics. With a specially designed spaceborne sodium lidar, however, scientists would be able to illuminate specific areas, revealing the small-scale dynamics that currently are the biggest unknown, Janches said.

    The team will use NASA’s funding to fine-tune the technology that locks the lidar onto the sodium lines. “It’s like a guitar string,” Krainak explained. “If you want a certain tone, you need to lock down the string at a particular length. It’s the same thing with the laser cavity length.”

    The team also plans to demonstrate an environmentally tested engineering test unit of the laser, thereby improving its technology-readiness level to six, which means that the technology is ready for flight development.

    “We’ve made significant progress on the laser,” Krainak said. “If we win, we could be the first space-based sodium laser spectrometer for remote sensing.”

    For more technology news, go to https://gsfctechnology.gsfc.nasa.gov/newsletter/Current.pdf

    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

     
  • richardmitnick 12:31 pm on May 18, 2017 Permalink | Reply
    Tags: , , , , NASA Goddard, NASA Mission Uncovers Dance of Electrons in Spac,   

    From Goddard: “NASA Mission Uncovers Dance of Electrons in Space” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    May 18, 2017
    Mara Johnson-Groh
    mara.johnson-groh@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Media contact: Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    1
    From video, via phys.org

    You can’t see them, but swarms of electrons are buzzing through the magnetic environment — the magnetosphere — around Earth. The electrons spiral and dive around the planet in a complex dance dictated by the magnetic and electric fields. When they penetrate into the magnetosphere close enough to Earth, the high-energy electrons can damage satellites in orbit and trigger auroras. Scientists with NASA’s Magnetospheric Multiscale, or MMS, mission study the electrons’ dynamics to better understand their behavior. A new study, published in Journal of Geophysical Research revealed a bizarre new type of motion exhibited by these electrons.

    Electrons in a strong magnetic field usually exhibit a simple behavior: They spin tight spirals along the magnetic field. In a weaker field region, where the direction of the magnetic field reverses, the electrons go free style — bouncing and wagging back and forth in a type of movement called Speiser motion. New MMS results show for the first time what happens in an intermediate strength field. Then these electrons dance a hybrid, meandering motion — spiraling and bouncing about before being ejected from the region. This motion takes away some of the field’s energy and it plays a key role in magnetic reconnection, a dynamic process, which can explosively release large amounts of stored magnetic energy.

    NASA/MMS

    NASA MMS satellites in space


    With no guide field to confine them, electrons (yellow) wiggle back in forth. The electron’s increasing speed is shown by warmer color tracks. Credits: NASA’s Goddard Space Flight Center/Tom Bridgman

    “MMS is showing us the fascinating reality of magnetic reconnection happening out there,” said Li-Jen Chen, lead author of the study and MMS scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

    As MMS flew around Earth, it passed through an area of a moderate strength magnetic field where electric currents run in the same direction as the magnetic field. Such areas are known as intermediate guide fields. While inside the region, the instruments recorded a curious interaction of electrons with the current sheet, the thin layer through which the current travels. As the incoming particles encountered the region, they started gyrating in spirals along the guide field, like they do in a strong magnetic field, but in larger spirals. The MMS observations also saw signatures of the particles gaining energy from the electric field. Before long, the accelerated particles escaped the current sheet, forming high-speed jets. In the process, they took away some of the field’s energy, causing it to gradually weaken.


    In an intermediate strength magnetic guide field, the electrons spiral along the field, gaining energy until they are ejected from the reconnection layer. Credits: NASA’s Goddard Space Flight Center/Tom Bridgman

    The magnetic field environment where the electrons’ motions were observed was uniquely created by magnetic reconnection, which caused the current sheet to be tightly confined by bunched-up magnetic fields. The new results help the scientists better understand the role of electrons in reconnection and how magnetic fields lose energy.

    MMS measures the electric and magnetic fields it flies through, and counts electrons and ions to measure their energies and directions of motion. With four spacecraft flying in a compact, pyramid formation, MMS is able to see the fields and particles in three dimensions and look at small-scale particle dynamics, in a way never before achieved.

    “The time resolution of MMS is one hundred times faster than previous missions,” said Tom Moore, senior project scientist for MMS at NASA’s Goddard Space Flight Center. “That means we can finally see what’s going on in such narrow layers and will be able to better predict how fast reconnection occurs in various circumstances.”

    Understanding the speed of reconnection is essential for predicting the intensity of the explosive energy release. Reconnection is an important energy release process across the universe and is thought to be responsible for some shock waves and cosmic rays. Solar flares on the sun, which can trigger space weather, are also caused by magnetic reconnection.

    With two years under its belt, MMS has been revealing new and surprising phenomena near Earth. These discoveries enable us to better understand Earth’s dynamic space environment and how it affects our satellites and technology.

    MMS is now heading to a new orbit which will take it through magnetic reconnection areas on the side of Earth farther from the sun. In this region, the guide field is typically weaker, so MMS may see more of these types of electron dynamics.

    Related Links

    Learn more about NASA’s MMS mission

    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 1:33 pm on May 9, 2017 Permalink | Reply
    Tags: Blobs and Bubbles, , Dellingr, GRIDS-Gridded Retarding Ion Drift Sensor, INMS-Goddard-developed Ion-Neutral Mass Spectrometer, NASA Goddard, PetitSat-Plasma Enhancements in The Ionosphere-Thermosphere Satellite   

    From Goddard: “NASA Team Pursues Blobs and Bubbles with New PetitSat Mission” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    May 9, 2017
    Lori Keesey
    NASA’s Goddard Space Flight Center

    Figuring out how plasma bubbles and blobs affect one another and ultimately the transmission of communications, GPS, and radar signals in Earth’s ionosphere will be the job of a recently selected CubeSat mission.

    A team of NASA scientists and engineers, led by Jeffrey Klenzing and Sarah Jones, scientists at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, recently won NASA funding to build the Plasma Enhancements in The Ionosphere-Thermosphere Satellite. The mission, also known as petitSat, is a precursor to a possible Explorer-class mission and leverages several R&D-supported technologies, including the satellite bus itself.

    1
    The Goddard-led petitSat team is basing its mission on a 6U CubeSat — Dellingr. Goddard engineers developed this small satellite to show that CubeSats could be both reliable and cost effective also while gathering compelling scientific data. The black-colored device at the top of the Dellingr 3-D model depicts the Ion-Neutral Mass Spectrometer that also is flying on petitSat.
    Credits: NASA/W. Hrybyk

    When it launches from the International Space Station in 2021, the mission will study density irregularities in the mid and low-latitude ionosphere, which occupies a tiny fraction of the atmosphere and is basically an ionized layer coexisting with the thermosphere roughly 50 to 250 miles above Earth’s surface.

    The ionosphere is a plasma, an ionized gas consisting of positive ions and free electrons. It is important to long-distance radio communication because it reflects radio waves back to Earth. Consequently, any perturbations in the density of the plasma interfere with GPS and radar signals.

    These perturbations or irregularities come in the form of ionospheric depletions or bubbles, structures that contain fewer electrons, and enhancements or blobs that contain a greater number of electrons. “All these irregularities can distort the transmission of radio waves,” said Klenzing, the mission principal investigator.

    Blobs and Bubbles: A Different Story

    Previous studies of the blobs indicate that they can be the direct result of bubbles forming near the geomagnetic equator, Klenzing said. Other observations, however, tell a different story. The blobs can be observed in regions where bubbles do not extend and can form when bubbles do not.

    They suggest that multiple mechanisms are at play, including fast-traveling waves coming from the thermosphere, a warm neutral atmospheric layer where most of the ionosphere resides. In fact, these wave-like thermospheric structures create waves in the ionosphere through ion-neutral drag — a phenomenon called Medium-Scale Traveling Ionospheric Disturbances, or MSTIDs. The resulting MSTIDs create electric fields that can transport energy from the summer hemisphere to the winter hemisphere. It is thought that the observed plasma blobs are the consequence of these electric fields.

    “Our mission will investigate the link between these two phenomena — enhanced plasma density measurements, or blobs, and the wave action in the thermosphere,” Klenzing said.

    To find out, the team will fly two instruments: a version of the Goddard-developed Ion-Neutral Mass Spectrometer, or INMS — the world’s smallest mass spectrometer that has flown on ExoCube, a CubeSat mission sponsored by the National Science Foundation — and the Gridded Retarding Ion Drift Sensor, or GRIDS, provided by Utah State University and Virginia Tech.

    The mass spectrometer will measure the densities of a variety of particles in the upper reaches of Earth’s atmosphere, observing how these densities change in response to daily and seasonal cycles. The university-provided instrument, meanwhile, will measure the distribution, motion, and velocity of ions.

    2
    PetitSat is flying a version of the Goddard-developed Ion-Neutral Mass Spectrometer (left) and the university-provided Gridded Retarding Ion Drift Sensor. Credits: NASA

    Dellingr-Based Mission

    The team will integrate its instruments on a Dellingr-based spacecraft. A team of Goddard engineers specifically created this 6U CubeSat to demonstrate that that these tiny craft could be reliable and cost-effective also while delivering compelling science. Dellingr, which also carries the INMS, magnetometers, and other technologies, is expected to launch in August.

    Unlike Dellingr whose solar panels are mounted on the side of the spacecraft, petitSat will fly deployable solar arrays — an enhancement that will allow mission operators to more easily point the arrays to the sun to recharge batteries. It also will carry a more advanced star tracker, said Jones, the INMS principal investigator.

    When petitSat is deployed 249 miles above Earth — consistent with the International Space Station’s orbit — the resulting data will be compared with that gathered by other ground- and space-based assets, Klenzing said. “Through comparative analysis, we will bring closure to our key science question: what is the link between plasma enhancements and MSTIDs. We’ve studied bits and pieces, but we’ve never had a full complement of instruments.”

    For more technology news, go to https://gsfctechnology.gsfc.nasa.gov/newsletter/Current.pdf

    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 4:30 pm on May 8, 2017 Permalink | Reply
    Tags: Berkeley, CME's, , NASA Goddard, , , Space Sciences Laboratory at University of California   

    From Goddard: “Space Weather Model Simulates Solar Storms From Nowhere” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    May 8, 2017
    Lina Tran
    kathalina.k.tran@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    Our ever-changing sun continuously shoots solar material into space. The grandest such events are massive clouds that erupt from the sun, called coronal mass ejections, or CMEs. These solar storms often come first with some kind of warning — the bright flash of a flare, a burst of heat or a flurry of solar energetic particles. But another kind of storm has puzzled scientists for its lack of typical warning signs: They seem to come from nowhere, and scientists call them stealth CMEs.

    Now, an international team of scientists, led by the Space Sciences Laboratory at University of California, Berkeley, and funded in part by NASA, has developed a model that simulates the evolution of these stealthy solar storms.


    SSL UC Berkeley campus


    Space Science Labs UC Berkeley

    The scientists relied upon NASA missions STEREO and SOHO for this work, fine-tuning their model until the simulations matched the space-based observations.

    NASA/STEREO spacecraft


    ESA/NASA SOHO

    Their work shows how a slow, quiet process can unexpectedly create a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space — all without any advance warning.

    1
    Watch the evolution of a stealth CME in this simulation. Differential rotation creates a twisted mass of magnetic fields on the sun, which then pinches off and speeds out into space. The image of the sun is from NASA’s STEREO. Colored lines depict magnetic field lines, and the different colors indicate in which layers of the sun’s atmosphere they originate. The white lines become stressed and form a coil, eventually erupting from the sun. Credits: NASA’s Goddard Space Flight Center/ARMS/Joy Ng, producer

    Compared to typical CMEs, which erupt from the sun as fast as 1800 miles per second, stealth CMEs move at a rambling gait — between 250 to 435 miles per second. That’s roughly the speed of the more common solar wind, the constant stream of charged particles that flows from the sun. At that speed, stealth CMEs aren’t typically powerful enough to drive major space weather events, but because of their internal magnetic structure they can still cause minor to moderate disturbances to Earth’s magnetic field.

    To uncover the origins of stealth CMEs, the scientists developed a model of the sun’s magnetic fields, simulating their strength and movement in the sun’s atmosphere. Central to the model was the sun’s differential rotation, meaning different points on the sun rotate at different speeds. Unlike Earth, which rotates as a solid body, the sun rotates faster at the equator than it does at its poles.

    The model showed differential rotation causes the sun’s magnetic fields to stretch and spread at different rates. The scientists demonstrated this constant process generates enough energy to form stealth CMEs over the course of roughly two weeks. The sun’s rotation increasingly stresses magnetic field lines over time, eventually warping them into a strained coil of energy. When enough tension builds, the coil expands and pinches off into a massive bubble of twisted magnetic fields — and without warning — the stealth CME quietly leaves the sun.

    Such computer models can help researchers better understand how the sun affects near-Earth space, and potentially improve our ability to predict space weather, as is done for the nation by the U.S. National Oceanic and Atmospheric Administration. A paper published in the Journal of Geophysical Research on Nov. 5, 2016, summarizes this work.

    Related

    New Space Weather Model Helps Simulate Magnetic Structure of Solar Storms
    NASA Scientists Demonstrate Technique to Improve Particle Warnings that Protect Astronauts

    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 7:32 am on April 25, 2017 Permalink | Reply
    Tags: , , , Heliosphere, Heliotail, NASA Goddard,   

    From Goddard: “NASA’s Cassini, Voyager Missions Suggest New Picture of Sun’s Interaction with Galaxy” 

    NASA Goddard Banner
    NASA Goddard Space Flight Center

    April 24, 2017
    Sarah Frazier
    sarah.frazier@nasa.gov
    NASA’s Goddard Space Flight Center, Greenbelt, Md.

    New data from NASA’s Cassini mission, combined with measurements from the two Voyager spacecraft and NASA’s Interstellar Boundary Explorer, or IBEX, suggests that our sun and planets are surrounded by a giant, rounded system of magnetic field from the sun — calling into question the alternate view of the solar magnetic fields trailing behind the sun in the shape of a long comet tail.

    NASA/Voyager 1

    NASA/ESA/ASI Cassini Spacecraft

    NASA/IBEX

    The sun releases a constant outflow of magnetic solar material — called the solar wind — that fills the inner solar system, reaching far past the orbit of Neptune. This solar wind creates a bubble, some 23 billion miles across, called the heliosphere. Our entire solar system, including the heliosphere, moves through interstellar space. The prevalent picture of the heliosphere was one of comet-shaped structure, with a rounded head and an extended tail. But new data covering an entire 11-year solar activity cycle show that may not be the case: the heliosphere may be rounded on both ends, making its shape almost spherical. A paper on these results was published in Nature Astronomy on April 24, 2017.

    “Instead of a prolonged, comet-like tail, this rough bubble-shape of the heliosphere is due to the strong interstellar magnetic field — much stronger than what was anticipated in the past — combined with the fact that the ratio between particle pressure and magnetic pressure inside the heliosheath is high,” said Kostas Dialynas, a space scientist at the Academy of Athens in Greece and lead author on the study.

    1
    New data from NASA’s Cassini, Voyager and Interstellar Boundary Explorer missions show that the heliosphere — the bubble of the sun’s magnetic influence that surrounds the inner solar system — may be much more compact and rounded than previously thought. The image on the left shows a compact model of the heliosphere, supported by this latest data, while the image on the right shows an alternate model with an extended tail. The main difference is the new model’s lack of a trailing, comet-like tail on one side of the heliosphere. This tail is shown in the old model in light blue.
    Credits: Dialynas, et al. (left); NASA (right)

    An instrument on Cassini, which has been exploring the Saturn system over a decade, has given scientists crucial new clues about the shape of the heliosphere’s trailing end, often called the heliotail. When charged particles from the inner solar system reach the boundary of the heliosphere, they sometimes undergo a series of charge exchanges with neutral gas atoms from the interstellar medium, dropping and regaining electrons as they travel through this vast boundary region. Some of these particles are pinged back in toward the inner solar system as fast-moving neutral atoms, which can be measured by Cassini.

    “The Cassini instrument was designed to image the ions that are trapped in the magnetosphere of Saturn,” said Tom Krimigis, an instrument lead on NASA’s Voyager and Cassini missions based at Johns Hopkins University’s Applied Physics Laboratory in Laurel, Maryland, and an author on the study. “We never thought that we would see what we’re seeing and be able to image the boundaries of the heliosphere.”

    2
    Many other stars show tails that trail behind them like a comet’s tail, supporting the idea that our solar system has one too. However, new evidence from NASA’s Cassini, Voyager and Interstellar Boundary Explorer missions suggest that the trailing end of our solar system may not be stretched out in a long tail. From top left and going counter clockwise, the stars shown are LLOrionis, BZ Cam and Mira. Credits: NASA/HST/R.Casalegno/GALEX

    Because these particles move at a small fraction of the speed of light, their journeys from the sun to the edge of the heliosphere and back again take years. So when the number of particles coming from the sun changes — usually as a result of its 11-year activity cycle — it takes years before that’s reflected in the amount of neutral atoms shooting back into the solar system.

    Cassini’s new measurements of these neutral atoms revealed something unexpected — the particles coming from the tail of the heliosphere reflect the changes in the solar cycle almost exactly as fast as those coming from the nose of the heliosphere.

    “If the heliosphere’s ‘tail’ is stretched out like a comet, we’d expect that the patterns of the solar cycle would show up much later in the measured neutral atoms,” said Krimigis.

    3
    5
    4
    The heliosphere is the bubble-like region of space dominated by the Sun, which extends far beyond the orbit of Pluto. Plasma “blown” out from the Sun, known as the solar wind, creates and maintains this bubble against the outside pressure of the interstellar medium, the hydrogen and helium gas that permeates the Milky Way Galaxy. The solar wind flows outward from the Sun until encountering the termination shock, where motion slows abruptly. The Voyager spacecraft have actively explored the outer reaches of the heliosphere, passing through the shock and entering the heliosheath, a transitional region which is in turn bounded by the outermost edge of the heliosphere, called the heliopause. The overall shape of the heliosphere is controlled by the interstellar medium through which it is traveling, as well as the Sun, and is not perfectly spherical.[1] The limited data available and unexplored nature[2] of these structures have resulted in many theories.
    Wikipedia.

    But because patterns from solar activity show just as quickly in tail particles as those from the nose, that implies the tail is about the same distance from us as the nose. This means that long, comet-like tail that scientists envisioned may not exist at all — instead, the heliosphere may be nearly round and symmetrical.

    A rounded heliosphere could come from a combination of factors. Data from Voyager 1 show that the interstellar magnetic field beyond the heliosphere is stronger than scientists previously thought, meaning it could interact with the solar wind at the edges of the heliosphere and compact the heliosphere’s tail.

    The structure of the heliosphere plays a big role in how particles from interstellar space — called cosmic rays — reach the inner solar system, where Earth and the other planets are.

    “This data that Voyager 1 and 2, Cassini and IBEX provide to the scientific community is a windfall for studying the far reaches of the solar wind,” said Arik Posner, Voyager and IBEX program scientist at NASA Headquarters in Washington, D.C., who was not involved with this study.

    “As we continue to gather data from the edges of the heliosphere, this data will help us better understand the interstellar boundary that helps shield the Earth environment from harmful cosmic rays.”

    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

     
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