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  • richardmitnick 1:01 pm on June 14, 2020 Permalink | Reply
    Tags: "NASA's Parker Solar Probe Teams Up With Observatories Around Solar System for 4th Solar Encounter", Heliophysics, Mauna Loa Solar Observatory, NASA MARS MAVEN, , , Poker Flat Incoherent Scatter Radar, Solar and Terrestrial Relations Observatory [STEREO], Whole Heliosphere and Planetary Interactions   

    From NASA Parker Solar Probe: “NASA’s Parker Solar Probe Teams Up With Observatories Around Solar System for 4th Solar Encounter” 

    NASA image

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

    From NASA Parker Solar Probe

    6.12.20

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

    At the heart of understanding our space environment is the knowledge that conditions throughout space — from the Sun to the atmospheres of planets to the radiation environment in deep space — are connected.

    Studying this connection – a field of science called heliophysics — is a complex task: Researchers track sudden eruptions of material, radiation, and particles against the background of the ubiquitous outflow of solar material.

    A confluence of events in early 2020 created a nearly ideal space-based laboratory, combining the alignment of some of humanity’s best observatories — including Parker Solar Probe, during its fourth solar flyby — with a quiet period in the Sun’s activity, when it’s easiest to study those background conditions. These conditions provided a unique opportunity for scientists to study how the Sun influences conditions at points throughout space, with multiple angles of observation and at different distances from the Sun.

    The Sun is an active star whose magnetic field is spread out through the solar system, carried within the Sun’s constant outflow of material called the solar wind, which affects spacecraft and shapes the environments of worlds throughout the solar system. We’ve observed the Sun, space near Earth and other planets, and even the most distant edges of the Sun’s sphere of influence for decades. And 2018 marked the launch of a new, game-changing observatory: Parker Solar Probe, with a plan to ultimately fly to about 3.83 million miles from the Sun’s visible surface.

    Parker has now had four close encounters of the Sun. (The data from Parker’s first encounters with the Sun has already revealed a new picture of its atmosphere.) During its fourth solar encounter, spanning parts of January and February 2020, the spacecraft passed directly between the Sun and Earth. This gave scientists a unique opportunity: The solar wind that Parker Solar Probe measured when it was closest to the Sun would, days later, arrive at Earth, where the wind itself and its effects could be measured by both spacecraft and ground-based observatories. Furthermore, solar observatories on and near Earth would have a clear view of the locations on the Sun that produced the solar wind measured by Parker Solar Probe.

    “We know from Parker data that there are certain structures originating at or near the solar surface. We need to look at the source regions of these structures to fully understand how they form, evolve, and contribute to the plasma dynamics in the solar wind,” said Nour Raouafi, project scientist for the Parker Solar Probe mission at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “Ground-based observatories and other space missions provide supporting observations that can help draw the full picture of what Parker is observing.”

    This celestial alignment would be of interest to scientists under any circumstances, but it also coincided with another astronomical period of interest to scientists: solar minimum. This is the point during the Sun’s regular, approximately 11-year cycles of activity when solar activity is at its lowest level — so sudden eruptions on the Sun such as solar flares, coronal mass ejections and energetic particle events are less likely. And that means that studying the Sun near solar minimum is a boon for scientists who can watch a simpler system and thus untangle which events cause which effects.

    “This period provides perfect conditions to trace the solar wind from the Sun to Earth and the planets,” said Giuliana de Toma, a solar scientist at the High Altitude Observatory in Boulder, Colorado, who led coordination among observatories for this observation campaign. “It is a time when we can follow the solar wind more easily, since we don’t have disturbances from the Sun.”

    For decades, scientists have pulled together observations during these periods of solar minimum, an effort co-led by Sarah Gibson, a solar scientist at the High Altitude Observatory, and other scientists. For each of the past three solar minimum periods, scientists pooled observations from an ever-expanding list of observatories in space and on the ground, hoping the wealth of data on the undisturbed solar wind would unveil new information about how it forms and evolves. For this solar minimum period, scientists began gathering coordinated observations starting in early 2019 under the umbrella Whole Heliosphere and Planetary Interactions, or WHPI for short.

    This particular WHPI campaign comprised a broader-than-ever swath of observations: covering not only the Sun and effects on Earth, but also data gathered at Mars and the nature of space throughout the solar system — all in concert with Parker Solar Probe’s fourth and closest-yet flyby of the Sun.

    The WHPI organizers brought together observers from all over the world — and beyond. Combining data from dozens of observatories on Earth and in space gives scientists a chance to paint what might be the most comprehensive picture ever of the solar wind: from images of its birth with solar telescopes, to samples shortly after it leaves the Sun with Parker Solar Probe, to multi-point observations of its changing state throughout space.

    Read on to see samples of the kinds of data captured during this international collaboration of Sun and space observatories.

    Parker Solar Probe

    2
    This animated sequence of visible-light images from Parker Solar Probe’s WISPR instrument shows a coronal streamer, observed when Parker Solar Probe was near perihelion on Jan. 28, 2020.
    Credits: NASA/Johns Hopkins APL/Naval Research Lab/Parker Solar Probe

    Early data from Parker Solar Probe’s close pass by the Sun during the WHPI campaign shows a solar wind system more dynamic than what’s visible in observations near Earth. In particular, scientists hope the full set of data — downlinked to Earth in May 2020 — will reveal dynamic structures, like tiny coronal mass ejections and magnetic flux ropes in their early stages of development, that can’t be seen with other observatories watching from farther away. Connecting structures like this, previously too small or too distant to see, with solar wind and near-Earth measurements may help scientists better understand how the solar wind changes throughout its lifetime and how its origins near the Sun affect its behavior throughout the solar system.

    Mauna Loa Solar Observatory

    Mauna Loa Solar Observatory

    Parker Solar Probe’s close-up views of solar wind structures are complemented by solar observatories on Earth and in space, which have a larger field of view to capture solar wind structures.

    Data from the Mauna Loa Solar Observatory in Hawaii shows a jet of material being ejected near the Sun’s south pole on Jan. 21, 2020. Coronal jets like this are one solar wind feature that scientists hope to observe more closely with Parker Solar Probe, as the mechanisms that create them could shed more light on the solar wind’s birth and acceleration.

    “It would be extremely fortunate if Parker Solar Probe observed this jet, since it would provide information on plasma and the field in and around the jet not long after its formation,” said Joan Burkepile, lead scientist for the Coronal Solar Magnetism Observatory K-coronagraph instrument at the Mauna Loa Solar Observatory, which captured these images.

    4
    Data from the Mauna Loa Solar Observatory in Hawaii shows a jet of material being ejected near the Sun’s south pole on Jan. 21, 2020 (UTC). This difference image is created by subtracting the pixels of the previous image from the current image to highlight changes. Credits: Mauna Loa Solar Observatory/K-Cor

    Solar and Terrestrial Relations Observatory [STEREO]

    NASA/STEREO spacecraft

    Along with observations of the solar wind from Parker Solar Probe and near Earth, scientists also have detailed images of the Sun and its atmosphere from spacecraft like NASA’s Solar Dynamics Observatory and the Solar and Terrestrial Relations Observatory. NASA’s Solar and Terrestrial Relations Observatory, or STEREO, has a distinct view of the Sun from its vantage point about 78 degrees away from Earth.

    During this WHPI campaign, scientists took advantage of this unique viewing angle. From Jan. 21-23 — when Parker Solar Probe and STEREO were aligned — the STEREO mission team increased the exposure length and frequency of images taken by its coronagraph, revealing fine structures in the solar wind as they speed out from the Sun.

    These difference images are created by subtracting the pixels of a previous image from the current image to highlight changes — here, revealing a small CME that would otherwise be difficult to see.


    NASA’s Solar and Terrestrial Relations Observatory, or STEREO, took extra images with longer exposure times to improve views of structure in the solar wind. These difference images, spanning Jan. 21-23, 2020, are created by subtracting the pixels of a previous image from the current image to highlight changes. Credits: NASA/STEREO

    Solar Dynamics Observatory


    NASA’s Solar Dynamics Observatory keeps a constant eye on the Sun. These images, captured in a wavelength of extreme ultraviolet light, span Jan. 15 – Feb. 11, 2020.
    Credits: NASA/SDO

    The Solar Dynamics Observatory, or SDO, takes high-resolution views of the entire Sun, revealing fine details on the solar surface and the lower solar atmosphere. These images were captured in a wavelength of extreme ultraviolet light at 171 Angstroms, highlighting the quiet parts of the Sun’s outer atmosphere, the corona. This data — along with SDO’s images in other wavelengths — maps much of the Sun’s activity, allowing scientists to connect solar wind measurements from Parker Solar Probe and other spacecraft with their possible origins on the Sun.

    NASA SDO

    Modeling the Data

    4
    The Sun’s “open” magnetic field — shown in this model in blue and red, with looped or closed field shown in yellow — primarily comes from near the Sun’s north and south poles during solar minimum, but it spreads out to fill space converging near the Sun’s equator. Credits: NASA/Nick Arge

    Ideally, scientists could use these images to readily pinpoint the region on the Sun that produced a particular stream of solar wind measured by Parker Solar Probe — but identifying the source of any given solar wind stream observed by a spacecraft is not simple. In general, the magnetic field lines that guide the solar wind’s movement flow out of the Northern half of the Sun point in the opposite direction than they do in the Southern half. In early 2020, Parker Solar Probe’s position was right at the boundary between the two – an area known as the heliospheric current sheet.

    “For this perihelion, Parker Solar Probe was very close to the current sheet, so a little nudge one way or the other would make the magnetic footpoint shift to the south or north pole,” said Nick Arge, a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We were on the tipping point where sometimes it went north, sometimes south.”

    Predicting which side of the tipping point Parker Solar Probe was on was the responsibility of the modeling teams. Using what we know about the Sun’s magnetic field and the clues we can glean from distant images of the Sun, they made day-by-day predictions of where, precisely, on the Sun birthed the solar wind that Parker would fly through on a given day. Several modeling groups made daily attempts to answer just that question.

    Using measurements of the magnetic field at the Sun’s surface, each group made a daily prediction for the source region producing the solar wind that Parker Solar Probe was flying through.

    Arge worked with Shaela Jones, a solar scientist at NASA Goddard who did daily forecasting during the WHPI campaign, using a model originally developed by Arge and colleagues Yi-Ming Wang and Neil Sheeley, called the WSA model. According to their forecasts, the predicted source of the solar wind switched between hemispheres suddenly during the observation campaign, because Earth’s orbit at the time was also closely aligned with the heliospheric current sheet – that region where the direction of magnetic polarity and the source of the solar wind switches between north and south. They predicted that Parker Solar Probe, flying in a similar plane as Earth, would experience similar switches in solar wind source and magnetic polarity as it flew near the Sun.

    6
    This model run — produced by Nick Arge and Shaela Jones using the WSA model — illustrates the predicted origin for solar wind that will impact Earth days later, spanning Jan. 10 – Feb. 3, 2020. The colored regions near the Sun’s north and south poles show the regions from which the solar wind flows out, with red regions showing a faster flow and blue regions showing a slower flow. The yellow lines on the Sun divide areas of opposite magnetic polarity. The white lines indicate the predicted points of origin for the solar wind arriving at Earth at the given date. The black and white underlaid image shows a map of the magnetic field at the Sun’s surface, the basis for the model’s predictions. The black regions are where the magnetic field points inward, toward the Sun, and white regions are where the field points outward, away from the Sun. Credits: NASA/Nick Arge/Shaela Jones

    Solar wind models rely on daily measurements of the Sun’s surface magnetic field — the black and white image underlaid. This particular model used measurements from the National Solar Observatory’s Global Oscillation Network Group and a model that focuses on predicting how the Sun’s surface magnetic field will change over several days. Creating these magnetic surface maps is a complicated and imperfect process unto itself, and some of the modeling groups participating in the WHPI campaign also used magnetic measurements from multiple observatories. This, along with differences in each group’s models, created a spread of predictions that sometimes placed the source of Parker Solar Probe’s solar wind stream in two different hemispheres of the Sun. But given the inherent uncertainty in modeling the solar wind’s source, these different predictions can actually make for more robust operations.

    “If you can observe the Sun in two different places with two telescopes, you have a better chance to get the right spot,” said Jones.

    Poker Flat Incoherent Scatter Radar

    The solar wind carries with it both an enormous amount of energy and the embedded magnetic field of the Sun. When it reaches Earth, it can ring our planet’s natural magnetic field like a bell, making it bend and deform — which produces a measurable change in magnetic field strength at certain points on Earth’s surface. We track those changes because magnetic field oscillations can lead to a host of space weather effects that interfere with spacecraft or even, occasionally, utility grids on the ground.

    A host of ground-based magnetometers have tracked these effects since the 1850s, and they’re one of the many sets of data scientists are gathering in connection with this campaign. Other ground-based instruments can reveal the invisible effects of space weather in our atmosphere. One such system is the Poker Flat Incoherent Scatter Radar, or PFISR — a radar system based at the Poker Flat Research Range near Fairbanks, Alaska.

    8
    The Poker Flat Incoherent Scatter Radar (PFISR) is located at the Poker Flat Research Range near Fairbanks, Alaska. It is a two-dimensional phased array radar consisting of 4096 transmitting and receiving elements. PFISR was built by SRI International on behalf of the National Science Foundation to conduct studies of the upper atmosphere and ionosphere in the auroral zone.

    This radar is specially tuned to detect one of most reliable indicators of a disturbance in Earth’s magnetic field: electrons in Earth’s upper atmosphere. These electrons are created when particles trapped in the magnetosphere are sent zooming into Earth’s atmosphere by a complex series of events, a set of circumstances known as a magnetospheric substorm.

    On Jan. 16, PFISR measured the changing electrons in Earth’s upper atmosphere during one such substorm. During a substorm, particles cascade into the upper atmosphere, not only creating the shower of electrons measured by the radar, but driving a more visible effect: the aurora. PFISR uses multiple beams of radar oriented in different directions, which allowed scientists to build up a three-dimensional picture of how electrons in the atmosphere changed throughout the substorm.


    The Poker Flat Incoherent Scatter Radar in Poker Flat, Alaska, makes 3-D measurements of electrons in Earth’s upper atmosphere. These electrons are produced by the same process that produces aurora, seen here by the Poker Flat All-Sky Camera, which images aurora over Alaska, on Jan. 16, 2020.
    Credits: Poker Flat Incoherent Scatter Radar (NSF)/Poker Flat All-Sky Camera (University of Alaska Fairbanks)/Don Hampton

    Because this substorm took place so early in the observation campaign — only one day after data collection began — it’s unlikely that it was caused by conditions on the Sun observed during the campaign. But even so, the connection between magnetospheric substorms and the broader, global-scale effects created by the solar wind — called geomagnetic storms — isn’t entirely understood.

    “This substorm didn’t happen during a geomagnetic storm time,” said Roger Varney, principal investigator for PFISR at SRI International in Menlo Park, California. “The solar wind during this event is fluctuating, but not particularly strongly — it’s basically background noise. But solar wind is basically never steady; it’s constantly putting some energy into the magnetosphere.”

    This deposit of energy into Earth’s magnetic system has far-reaching effects: for one, changes in the composition and density of Earth’s upper atmosphere can garble communications and navigation signals, an effect often characterized by total electron content. Changes in density can also affect the orbits of satellites to great degree, introducing uncertainty about precise position.

    MAVEN

    NASA Mars MAVEN

    Earth isn’t the only planet where the solar wind has measurable effects — and studying other worlds in our solar system can help scientists understand some of the solar wind’s effects on Earth and how it influenced the evolution of Earth and other worlds throughout the solar system’s history.

    At Mars, the solar wind coupled with Mars’ lack of a global magnetic field may be a major factor in the dry, barren world the Red Planet is today. Though Mars was once much like Earth — warm, with liquid water and a thick atmosphere — the planet has changed drastically over the course of its four-billion-year history, with most of its atmosphere being stripped away to space. With similar processes observed here on Earth, scientists leverage understanding of solar-planetary interactions at Mars to determine how processes leading to atmospheric escape has the ability to change whether a planet is habitable or not. Today, the Mars Atmosphere and Volatile Evolution mission, or MAVEN, studies these processes at Mars. MAVEN observations at Mars are available for this latest WHPI campaign.

    ______________________________________________-

    Over the coming months, heliophysicists around the world will begin to study data from these observatories in depth, hoping to draw connections that reveal new knowledge about the Sun and its changes that influence Earth and space across the solar system.

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

    The research discussed in this story includes work supported by the Poker Flat Incoherent Scatter Radar which is a major facility funded by the National Science Foundation through cooperative agreement AGS-1840962 to SRI International and work at the National Center for Atmospheric Research funded by the National Science Foundation through cooperative agreement AGS-1852977. Support for the WHPI Campaigns is provided through the NASA’s Heliophysics System Observatory Connect (HSO Connect) program.

    See the full article here .

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    Stem Education Coalition

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

    For more information about Parker, visit:

    https://www.nasa.gov/parker

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

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

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

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

     
  • richardmitnick 12:03 pm on May 24, 2019 Permalink | Reply
    Tags: "Plasma Processes in Mars’s Shadow", , , , , , NASA MARS MAVEN   

    From AAS NOVA: “Plasma Processes in Mars’s Shadow” 

    AASNOVA

    From AAS NOVA

    24 May 2019
    Kerry Hensley

    1
    NASA’s MAVEN spacecraft has been in orbit around Mars since 2014. The goal of the MAVEN mission is to understand how Mars’s atmosphere has evolved over the course of solar system history. [NASA/Goddard]

    NASA Mars MAVEN

    When solar ultraviolet and X-ray photons collide with atoms and molecules in Mars’s atmosphere, they form a layer of plasma called an ionosphere. That’s what happens on the sunlit side, at least. What’s going on in Mars’s shadow?

    2
    A cartoon depicting the interaction of the solar wind with Mars’s atmosphere, as well as likely regions for atmospheric escape. [NASA/GSFC]

    Planetary Plasma

    Even though there are no solar photons striking Mars’s atmosphere at night, plasma is still present — but it’s not immediately clear where it comes from. Does it come from bombardment by galactic cosmic rays or trapped solar-wind particles, or is it transported from the sunlit side by winds?

    And once the plasma has been produced, what happens to it? Is it lost when electrons and ions reunite to form neutrals, or does it escape the planet’s atmosphere entirely?

    One way to assess the sources and sinks of plasma is by calculating the rates of production by electron-impact ionization — when energetic electrons ionize neutrals through collisions — and loss by dissociative recombination — when molecular ions capture an electron and are split apart. If the rates are equal, those two processes dominate. If not, other processes must play a role.

    3
    From left to right, the densities of the major ion and neutral species, neutral (black) and electron (red) temperatures, and the average electron intensity. [Adapted from Cui et al. 2019]

    MAVEN on a Mission

    Evaluating whether or not the two rates are equal requires neutral and ion densities, electron temperatures, and a spectrum of incident energetic electrons. Luckily, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, which has been orbiting Mars since 2014, collects all that information and more.

    Normally, MAVEN comes within 150 km of Mars’s surface, but it occasionally drops its closest approach to 125 km. These so-called Deep Dip campaigns, of which there have been nine, give scientists a close look at the densest plasma in the ionosphere. In this study, a team led by Jun Cui (Sun Yat-sen University, Chinese Academy of Sciences, and National Astronomical Observatories, China) analyzed data from two Deep Dip orbits in 2015 and 2016.

    Using the in-situ measurements made along each orbit, Cui and collaborators calculated the rate at which CO2 — the dominant neutral species — is ionized by electron impacts and the rate at which O2+, NO+, and HCO+ — the three dominant ion species — dissociatively recombine.

    4
    Comparison of the dissociative recombination and electron-impact ionization rates for the two orbits. Open circles represent calculations made with individual measurements, while closed squares indicate average values for each altitude bin. The starred points have been corrected for instrumental effects. [Cui et al. 2019]

    A Complex Nightside Picture

    At low altitudes (below 140 km for the midnight orbit and 180 km for the dawn orbit), the authors found that the electron-impact ionization rate agrees with the dissociative recombination rate, which indicates that sources of plasma other than electron-impact ionization don’t play a major role at these altitudes.

    At high altitudes, however, the rate of electron-impact ionization is higher than the rate of dissociative recombination, which is a sign that there is another important plasma loss process happening at those altitudes. It’s possible that magnetic pressure gradients at those altitudes encourage ions to escape down Mars’s magnetotail.

    Last month, MAVEN finished its two-month aerobraking campaign, during which the spacecraft altitude dipped as low as ~125 km to use atmospheric drag to change its orbit, giving scientists a long look at Mars’s ionosphere. Expect more atmospheric news from MAVEN in the future!

    Citation

    “Evaluating Local Ionization Balance in the Nightside Martian Upper Atmosphere during MAVEN Deep Dip Campaigns,” J. Cui et al 2019 ApJL 876 L12.
    https://iopscience.iop.org/article/10.3847/2041-8213/ab1b34/meta

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

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

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

    Adopted June 7, 2009

     
  • richardmitnick 10:02 am on October 23, 2016 Permalink | Reply
    Tags: , , NASA MARS MAVEN, NASA’s MAVEN Mission Observes Ups and Downs of Water Escape from Mars   

    From astrobio.net: “NASA’s MAVEN Mission Observes Ups and Downs of Water Escape from Mars” 

    Astrobiology Magazine

    Astrobiology Magazine

    Oct 22, 2016
    No writer credit found

    1
    NASA

    After investigating the upper atmosphere of the Red Planet for a full Martian year, NASA’s MAVEN mission has determined that the escaping water does not always go gently into space.

    Sophisticated measurements made by a suite of instruments on the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft revealed the ups and downs of hydrogen escape – and therefore water loss. The escape rate peaked when Mars was at its closest point to the sun and dropped off when the planet was farthest from the sun. The rate of loss varied dramatically overall, with 10 times more hydrogen escaping at the maximum.

    “MAVEN is giving us unprecedented detail about hydrogen escape from the upper atmosphere of Mars, and this is crucial for helping us figure out the total amount of water lost over billions of years,” said Ali Rahmati, a MAVEN team member at the University of California at Berkeley who analyzed data from two of the spacecraft’s instruments.

    Hydrogen in Mars’ upper atmosphere comes from water vapor in the lower atmosphere. An atmospheric water molecule can be broken apart by sunlight, releasing the two hydrogen atoms from the oxygen atom that they had been bound to. Several processes at work in Mars’ upper atmosphere may then act on the hydrogen, leading to its escape.

    This loss had long been assumed to be more-or-less constant, like a slow leak in a tire. But previous observations made using NASA’s Hubble Space Telescope and ESA’s Mars Express orbiter found unexpected fluctuations. Only a handful of these measurements have been made so far, and most were essentially snapshots, taken months or years apart. MAVEN has been tracking the hydrogen escape without interruption over the course of a Martian year, which lasts nearly two Earth years.

    2
    This image shows atomic hydrogen scattering sunlight in the upper atmosphere of Mars, as seen by the Imaging Ultraviolet Spectrograph on NASA’s Mars Atmosphere and Volatile Evolution mission. About 400,000 observations, taken over the course of four days shortly after the spacecraft entered orbit around Mars, were used to create the image. Hydrogen is produced by the breakdown of water, which was once abundant on Mars’ surface. Because hydrogen has low atomic mass and is weakly bound by gravity, it extends far from the planet (the darkened circle) and can readily escape. Credits: NASA/Goddard/University of Colorado

    “Now that we know such large changes occur, we think of hydrogen escape from Mars less as a slow and steady leak and more as an episodic flow – rising and falling with season and perhaps punctuated by strong bursts,” said Michael Chaffin, a scientist at the University of Colorado at Boulder who is on the Imaging Ultraviolet Spectrograph (IUVS) team. Chaffin is presenting some IUVS results on Oct. 19 at the joint meeting of the Division for Planetary Sciences and the European Planetary Science Congress in Pasadena, California.

    In the most detailed observations of hydrogen loss to date, four of MAVEN’s instruments detected the factor-of-10 change in the rate of escape. Changes in the density of hydrogen in the upper atmosphere were inferred from the flux of hydrogen ions – electrically charged hydrogen atoms – measured by the Solar Wind Ion Analyzer and by the Suprathermal and Thermal Ion Composition instrument. IUVS observed a drop in the amount of sunlight scattered by hydrogen in the upper atmosphere. MAVEN’s magnetometer found a decrease in the occurrence of electromagnetic waves excited by hydrogen ions, indicating a decrease in the amount of hydrogen present.

    By investigating hydrogen escape in multiple ways, the MAVEN team will be able to work out which factors drive the escape. Scientists already know that Mars’ elliptical orbit causes the intensity of the sunlight reaching Mars to vary by 40 percent during a Martian year. There also is a seasonal effect that controls how much water vapor is present in the lower atmosphere, as well as variations in how much water makes it into the upper atmosphere. The 11-year cycle of the sun’s activity is another likely factor.

    “In addition, when Mars is closest to the sun, the atmosphere becomes turbulent, resulting in global dust storms and other activity. This could allow the water in the lower atmosphere to rise to very high altitudes, providing an intermittent source of hydrogen that can then escape,” said John Clarke, a Boston University scientist on the IUVS team. Clarke will present IUVS measurements of hydrogen and deuterium – a form of hydrogen that contains a neutron and is heavier – on Oct. 19 at the planetary conference.

    By making observations for a second Mars year and during different parts of the solar cycle, the scientists will be better able to distinguish among these effects. MAVEN is continuing these observations in its extended mission, which has been approved until at least September 2018.

    “MAVEN’s findings reveal what is happening in Mars’ atmosphere now, but over time this type of loss contributed to the global change from a wetter environment to the dry planet we see today,” said Rahmati.

    See the full article here .

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    NASA

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

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

    NASA Goddard Banner

    NASA Goddard Space Flight Center

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

    Bill Steigerwald
    william.a.steigerwald@nasa.gov

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

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

    NASA/Mars MAVEN
    NASA/Mars MAVEN


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

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

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

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

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

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

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

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

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

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

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

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

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

     
  • richardmitnick 2:44 pm on February 20, 2016 Permalink | Reply
    Tags: , , NASA MARS MAVEN,   

    From SSL: “MAVEN Instruments Study the Solar Wind at Mars” 

    SSL UC Berkeley

    Space Science Lab, UC Berkeley

    February 20, 2016
    Christopher Scholz

    The ‪MAVEN‬ spacecraft is equipped with several instruments devoted to measuring the solar wind and how solar energetic particles and extreme ultraviolet irradiance interact with Mars’ upper atmosphere.

    Solar Wind Electron Analyzer (SWEA)-The Solar Wind Electron Analyzer (SWEA) is a part of the Particles and Fields (P&F) Package and will measure the solar wind and ionospheric electrons.

    Goals:

    Deduce magneto-plasma topology in and above the Martian ionosphere based on electron spectra and pitch angle distributions
    Measure atmospheric electron impact ionization effects

    Observations:

    Measure energy and angle distributions of electrons in the Mars environment
    Determine magnetic topology from pitch angle distributions
    Measure solar wind, sheath and primary ionospheric photoelectron spectrum
    Determine electron impact ionization rates
    Measure auroral electron populations
    Evaluate plasma environment

    Technical details and heritage:

    Hemispherical Electrostatic Analyzer with deflectors
    Electrons with energies from 5 eV to 4.6 keV
    FOV 360o x 120o (Azimuth x Elevation)
    Angular resolution 22.5o in azimuth x 20o in elevation
    Energy fluxes 103 to 109 eV/cm2-s-ster-eV
    Energy resolution: ΔE/E = 17%, FWHM (capability for 9% below 50 eV)
    Time resolution: 2 sec
    Mounted at end of 1.5-meter boom
    Heritage from STEREO SWEA

    Solar Wind Ion Analyzer (SWIA)-The Solar Wind Ion Analyzer (SWIA) is a part of the Particles and Fields (P&F) Package and measures the solar wind and magnetosheath proton flow around Mars and constrains the nature of solar wind interactions with the upper atmosphere.

    Goals:

    Determine the ionization rates of neutrals from charge exchange, as an input to atmospheric loss processes
    Determine the pickup acceleration of newly formed ions by the v x B electric field
    Measure the flow of solar wind energy through the Martian magnetosphere
    Measure the structure and variability of the Martian magnetosphere
    Measure basic space plasma phenomena, including reconnection, flux ropes, plasmoids, bulk plasma escape, auroral processes, and boundary instabilities, throughout the Martian system

    Observations:

    Measure the properties of solar wind and magnetosheath ions, including density, temperature, and velocity, in order to determine the energy input to the upper atmosphere, the charge exchange rate, and the bulk plasma flow from solar wind speeds (~350 to ~1000 km/s) down to stagnating magnetosheath speeds (tens of km/s)

    Technical details and heritage:

    Coarse 3d covers 360°x90° with 22.5° resolution and energies 5 eV/q – 25 keV/q
    Fine 3d covers solar wind beam w/ 4.5° resolution and 10% energy windows
    Intrinsic time resolution of 4 s
    Mechanical attenuator provides variable dynamic range to cover from tenuous magnetosphere up to extreme solar wind fluxes [5×104 to 7×1011 eV/(cm2 s sr eV)]
    Heritage from Wind, FAST, and THEMIS

    Suprathermal and Thermal Ion Composition (STATIC)-The Suprathermal and Thermal Ion Composition (STATIC) instrument is part of the Particles and Fields (P&F) Package and measures thermal ions to moderate energy escaping ions.

    Goals:

    Measure the source ion populations near periapsis, the heated ionospheric ions at intermediate altitudes that achieve escape velocity, and the pickup acceleration of these ions in the magnetosheath and solar wind
    Allow direct measurements of the Martian sheath plasma, separating shocked solar wind and planetary ions that populate the sheath and plasma sheet

    Observations:

    Escaping ions and processes
    Composition of thermal to energetic ions; energy distributions and pitch angle variations
    Ionospheric Ions 0.1-10 eV
    Tail Superthermal ions (5-100eV)
    Pick-up Ions (100-20,000 eV)
    Key ions H+, O+, O2+, CO2+

    Technical details and heritage:

    Toroidal Electrostatic Analyzer with Time of Flight section
    Mass Range 1-70 AMU, ΔM/M > 4
    Energy range ~0.1 eV to 30 keV, ΔE/E~15%
    FOV 360o X 90o
    Angular Resolution 22.5o x 6o
    Energy Flux < 104 to 109 eV/cm2-s-sr-eV (to 1012 w/attenuators for low energy beam)
    Can be oriented to measure either upwelling/downwelling or horizontal flows
    Heritage from Cluster CODIF

    Solar Energetic Particle (SEP)-The Solar Energetic Particle (SEP) instrument is part of the Particles and Fields (P&F) Package and determines the impact of SEPs on the upper atmosphere.

    Goals:

    Determine SEP input into the atmosphere as a function of altitude
    Determine SEP heating, ionization, and sputtering of upper atmosphere
    Detect the highest energy pickup ions (>30 to 100s of keV)

    Observations:

    Characterize solar particles in an energy range that affects upper atmosphere and ionospheric processes (~120 – 200 km)
    Time resolution adequate to capture major SEP events (<1 hour)

    Technical details and heritage:

    Two dual double-ended telescopes
    Four look directions per species, optimized for parallel and perpendicular Parker Spiral viewing
    Protons and heavier ions from ~25 keV to 12 MeV
    Electrons from ~25 keV to 1 MeV
    Energy fluxes 10 to 106 eV/cm2-sec-ster-eV
    Better than 50% energy resolution
    Heritage from (nearly identical to) SST on THEMIS

    Langmuir Probe and Waves (LPW)Langmuir Probe and Waves (LPW)-The Langmuir Probe and Waves (LPW) instrument is part of the Particles and Fields (P&F) Package and determines ionospheric properties, wave heating of the upper atmosphere, and solar EUV input to the atmosphere.

    Goals:

    Measure the in situ electron density and electron temperature from the ionospheric peak up to the nominal ionopause location. It will also measure the electric field wave power important for ion heating
    Characterize the basic state of the ionosphere—its global structure, variability, and thermal properties
    Determine the effects of solar wind generated plasma waves and auroral precipitation on ionosphere heating and relationship to plasma escape
    Determine the electron temperatures required for deriving ion recombination rates and ionospheric chemistry
    Identify the ionopause and detached, escaping ionosphere clouds

    Observations:

    Electron temperature and number density throughout upper atmosphere
    Electric field wave power at low frequencies important for ion heating
    Wave spectra of naturally emitted and actively stimulated Langmuir waves to calibrate density measurements

    Technical details and heritage:

    Cylindrical sensors on two 7-meter booms
    Sensor I-V sweeps (at least ±50 V range)
    Low frequency (f: 0.05-10 Hz) E-field power; sensitivity 10-8 (V/m)2/Hz (f0/f)2 where fo=10 Hz and 100% bandwidth
    E-Spectra measurements up to 2 MHz
    White noise (50 kHz – 2 MHz ) sounding
    Thermal Electron density 100 to 106 cm-3
    Electron temperatures 500 to 5000oK
    Heritage from THEMIS and RBSP

    Extreme Ultraviolet (EUV) Monitor-The Extreme Ultraviolet (EUV) monitor is part of the Langmuir Probe and Waves (LPW) instrument and measures solar EUV input and variability, and wave heating of the Martian upper atmosphere.

    Goals:

    Measure solar emissions from different regions of the Sun in three distinct EUV bands
    Three channels will provide a complete EUV spectrum (0.1-190 nm) to serve as a proxy for input to the Flare Irradiance Spectral Model (FISM) model

    Observations:

    Solar EUV irradiance variability at wavelengths important for ionization, dissociation, and heating of the upper atmosphere (wavelengths shortward of HI Ly-α 121.6 nm)

    Technical details and heritage:

    Three photometers at key wavelengths representing different temperature solar emissions (0.1-7, 17-22, and 121.6 nm)
    Full spectrum (0-200 nm) derived from measurements using Flare Irradiance Spectral Model (FISM)
    Heritage from TIMED, SORCE, SDO, and rocket instruments

    Magnetometer (MAG)-The Magnetometer (MAG) is a part of the Particles and Fields (P&F) Package and measures interplanetary solar wind and ionospheric magnetic fields.

    Goals:

    Measure vector magnetic field
    Characterize solar wind interaction
    Support particles and fields package (ions, electrons, energetic particles & waves)

    Observations:

    Vector magnetic field in the unperturbed solar wind (B ~ 3 nT), magnetosheath (B ~ 10-50 nT), and crustal magnetospheres (B < 3000 nT), with the ability to spatially resolve crustal magnetic cusps (horizontal length scales of ~100 km)

    Technical details and heritage:

    Two sensors, outboard of solar array
    Magnetic field over a dynamic range of ~60,000 nT; resolution 0.05 nT
    32 samples/sec intrinsic sample rate averaged and decimated as necessary
    Sensor scale factor accuracy of 0.05%
    Heritage from MGS, Voyager, AMPTE, GIOTTO, CLUSTER, Lunar Prospector, MESSENGER , STEREO, Juno, and Van Allen Probes

    NASA MAVEN
    NASA/Mars MAVEN

    These experiments have been specifically designed to determine whether space weather events increase atmospheric escape rates to historically important levels.

    In analyzing data from these instruments, MAVEN scientists will take three approaches to derive the history of Mars’ atmosphere:

    1. Use ratios of stable isotopes to determine the integrated loss to space
    2. Use observed changes in escape in response to changing energetic inputs to directly extrapolate back in time
    3. Model escape processes using current conditions and extrapolate models back in time

    Taking these approaches enables our team scientists to determine how various space weather events affect the upper atmosphere of Mars today and how they have contributed to its evolution over time. Capturing events of different magnitudes becomes more likely over time and contributes to producing more accurate model extrapolations back in time.

    MAVEN data is allowing scientists to:

    Investigate atmospheric escape response to regular solar wind variations and to major events (solar flares, coronal mass ejections)
    Update an estimate of solar wind evolution
    Determine how solar energetic particles contribute to escape, and
    Estimate integrated historical loss to space

    NASA Goddard

    For images, fuller descriptions, publications, see the original SSL article.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    SSL UC Berkeley campus

     
  • richardmitnick 1:55 pm on March 18, 2015 Permalink | Reply
    Tags: , , , NASA MARS MAVEN   

    From NASA Goddard: “NASA Spacecraft Detects Aurora and Mysterious Dust Cloud around Mars” 

    NASA Goddard Banner
    Goddard Space Flight Center

    March 18, 2015
    Dwayne Brown
    Headquarters, Washington
    dwayne.c.brown@nasa.gov
    202-358-1726

    Nancy Neal-Jones
    Goddard Space Flight Center, Greenbelt, Md.
    nancy.n.jones@nasa.gov
    301-286-0039

    Bill Steigerwald
    Goddard Space Flight Center, Greenbelt, Md.
    william.a.steigerwald@nasa.gov
    301-286-5017

    Jim Scott
    University of Colorado, Boulder, Colorado
    jim.scott@colorado.edu

    1
    Artist’s conception of MAVEN’s Imaging UltraViolet Spectrograph (IUVS) observing the “Christmas Lights Aurora” on Mars. MAVEN observations show that aurora on Mars is similar to Earth’s “Northern Lights” but has a different origin. Image Credit: University of Colorado

    NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has observed two unexpected phenomena in the Martian atmosphere: an unexplained high-altitude dust cloud and aurora that reaches deep into the Martian atmosphere.

    The presence of the dust at orbital altitudes from about 93 miles (150 kilometers) to 190 miles (300 kilometers) above the surface was not predicted. Although the source and composition of the dust are unknown, there is no hazard to MAVEN and other spacecraft orbiting Mars.

    “If the dust originates from the atmosphere, this suggests we are missing some fundamental process in the Martian atmosphere,” said Laila Andersson of the University of Colorado’s Laboratory for Atmospherics and Space Physics (CU LASP), Boulder, Colorado.

    The cloud was detected by the spacecraft’s Langmuir Probe and Waves (LPW) instrument, and has been present the whole time MAVEN has been in operation. It is unknown if the cloud is a temporary phenomenon or something long lasting. The cloud density is greatest at lower altitudes. However, even in the densest areas it is still very thin. So far, no indication of its presence has been seen in observations from any of the other MAVEN instruments.

    Possible sources for the observed dust include dust wafted up from the atmosphere; dust coming from Phobos and Deimos, the two moons of Mars; dust moving in the solar wind away from the sun; or debris orbiting the sun from comets. However, no known process on Mars can explain the appearance of dust in the observed locations from any of these sources.

    2
    A map of IUVS’s auroral detections in December 2014 overlaid on Mars’ surface. The map shows that the aurora was widespread in the northern hemisphere, not tied to any geographic location. The aurora was detected in all observations during a 5-day period. Image Credit: University of Colorado

    MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) observed what scientists have named “Christmas lights.” For five days just before Dec. 25, MAVEN saw a bright ultraviolet auroral glow spanning Mars’ northern hemisphere. Aurora, known on Earth as northern or southern lights, are caused by energetic particles like electrons crashing down into the atmosphere and causing the gas to glow.

    “What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs – much deeper than at Earth or elsewhere on Mars,” said Arnaud Stiepen, IUVS team member at the University of Colorado. “The electrons producing it must be really energetic.”

    The source of the energetic particles appears to be the sun. MAVEN’s Solar Energetic Particle instrument detected a huge surge in energetic electrons at the onset of the aurora. Billions of years ago, Mars lost a global protective magnetic field like Earth has, so solar particles can directly strike the atmosphere. The electrons producing the aurora have about 100 times more energy than you get from a spark of house current, so they can penetrate deeply in the atmosphere.

    The findings are being presented at the 46th Lunar and Planetary Science Conference in The Woodlands, Texas.

    MAVEN was launched to Mars on Nov. 18, 2013, to help solve the mystery of how the Red Planet lost most of its atmosphere and much of its water. The spacecraft arrived at Mars on Sept. 21, and is four months into its one-Earth-year primary mission.

    “The MAVEN science instruments all are performing nominally, and the data coming out of the mission are excellent,” said Bruce Jakosky of CU LASP, Principal Investigator for the mission.

    MAVEN is part of the agency’s Mars Exploration Program, which includes the Opportunity and Curiosity rovers, the Mars Odyssey and Mars Reconnaissance Orbiter spacecraft currently orbiting the planet.

    NASA Mars Opportunity Rover
    Opportunity

    NASA Mars Curiosity Rover
    Curiosity

    NASA Mars Odessy Orbiter
    Odyssey

    NASA Mars Reconnaisence Orbiter
    Reconnaissance

    NASA’s Mars Exploration Program seeks to characterize and understand Mars as a dynamic system, including its present and past environment, climate cycles, geology and biological potential. In parallel, NASA is developing the human spaceflight capabilities needed for its journey to Mars or a future round-trip mission to the Red Planet in the 2030’s.

    MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project. Partner institutions include Lockheed Martin, the University of California at Berkeley, and NASA’s Jet Propulsion Laboratory.

    For images related to the findings, visit:

    http://www.nasa.gov/maven

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

    NASA Goddard Campus
    NASA/Goddard Campus
    NASA

     
  • richardmitnick 3:51 pm on December 15, 2014 Permalink | Reply
    Tags: , , , , , , NASA MARS MAVEN   

    From NASA/Goddard: “NASA’s MAVEN Mission Identifies Links in Chain Leading to Atmospheric Loss” 

    NASA Goddard Banner

    December 15, 2014

    Nancy Neal-Jones
    NASA’s Goddard Space Flight Center, Greenbelt, Maryland
    301-286-0039
    nancy.n.jones@nasa.gov

    Elizabeth Zubritsky
    NASA’s Goddard Space Flight Center, Greenbelt, Maryland
    301-614-5438
    elizabeth.a.zubritsky@nasa.gov

    Early discoveries by NASA’s newest Mars orbiter are starting to reveal key features about the loss of the planet’s atmosphere to space over time.

    The findings are among the first returns from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, which entered its science phase on Nov. 16. The observations reveal a new process by which the solar wind can penetrate deep into a planetary atmosphere. They include the first comprehensive measurements of the composition of Mars’ upper atmosphere and electrically charged ionosphere. The results also offer an unprecedented view of ions as they gain the energy that will lead to their to escape from the atmosphere.

    NASA Mars MAVEN
    NASA/MAVEN

    “We are beginning to see the links in a chain that begins with solar-driven processes acting on gas in the upper atmosphere and leads to atmospheric loss,” said Bruce Jakosky, MAVEN principal investigator with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. “Over the course of the full mission, we’ll be able to fill in this picture and really understand the processes by which the atmosphere changed over time.”

    On each orbit around Mars, MAVEN dips into the ionosphere – the layer of ions and electrons extending from about 75 to 300 miles above the surface. This layer serves as a kind of shield around the planet, deflecting the solar wind, an intense stream of hot, high-energy particles from the sun.

    Scientists have long thought that measurements of the solar wind could be made only before these particles hit the invisible boundary of the ionosphere. MAVEN’s Solar Wind Ion Analyzer, however, has discovered a stream of solar-wind particles that are not deflected but penetrate deep into Mars’ upper atmosphere and ionosphere.

    Interactions in the upper atmosphere appear to transform this stream of ions into a neutral form that can penetrate to surprisingly low altitudes. Deep in the ionosphere, the stream emerges, almost Houdini-like, in ion form again. The reappearance of these ions, which retain characteristics of the pristine solar wind, provides a new way to track the properties of the solar wind and may make it easier to link drivers of atmospheric loss directly to activity in the upper atmosphere and ionosphere.

    MAVEN’s Neutral Gas and Ion Mass Spectrometer is exploring the nature of the reservoir from which gases are escaping by conducting the first comprehensive analysis of the composition of the upper atmosphere and ionosphere. These studies will help researchers make connections between the lower atmosphere, which controls climate, and the upper atmosphere, where the loss is occurring.

    The instrument has measured the abundances of many gases in ion and neutral forms, revealing well-defined structure in the upper atmosphere and ionosphere, in contrast to the lower atmosphere, where gases are well-mixed. The variations in these abundances over time will provide new insights into the physics and chemistry of this region and have already provided evidence of significant upper-atmospheric “weather” that has not been measured in detail before.

    New insight into how gases leave the atmosphere is being provided by the spacecraft’s Suprathermal and Thermal Ion Composition (STATIC) instrument. Within hours after being turned on at Mars, STATIC detected the “polar plume” of ions escaping from Mars. This measurement is important in determining the rate of atmospheric loss.

    As the satellite dips down into the atmosphere, STATIC identifies the cold ionosphere at closest approach and subsequently measures the heating of this charged gas to escape velocities as MAVEN rises in altitude. The energized ions ultimately break free of the planet’s gravity as they move along a plume that extends behind Mars.

    The MAVEN spacecraft and its instruments have the full technical capability proposed in 2007 and are on track to carry out the primary science mission. The MAVEN team delivered the spacecraft to Mars on schedule, launching on the very day in 2013 projected by the team 5 years earlier. MAVEN was also delivered well under the confirmed budget established by NASA in 2010.

    The team’s success can be attributed to a focused science mission that matched the available funding and diligent management of resources. There were also minimal changes in requirements on the hardware or science capabilities that could have driven costs. It also reflects good coordination between the principal investigator; the project management at NASA’s Goddard Space Flight Center; the Mars Program Office at NASA’s Jet Propulsion Laboratory in Pasadena, California; and the Mars Exploration Program at NASA Headquarters.

    The entire project team contributed to MAVEN’s success to date, including the management team, the spacecraft and science-instrument institutions, and the launch-services provider.

    “The MAVEN spacecraft and its instruments are fully operational and well on their way to carrying out the primary science mission,” said Jim Green, director of NASA’s Planetary Science Division at NASA Headquarters in Washington. “The management team’s outstanding work enabled the project to be delivered on schedule and under budget.”

    MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the mission.

    For more information about NASA’s MAVEN mission, visit: http://www.nasa.gov/maven

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

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

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

    NASA Goddard Campus
    NASA/Goddard Campus
    NASA

     
  • richardmitnick 3:01 pm on October 14, 2014 Permalink | Reply
    Tags: , , , , , NASA MARS MAVEN   

    From NASA: “NASA Mission Provides Its First Look at Martian Upper Atmosphere” 

    NASA

    NASA

    October 14, 2014
    Dwayne Brown
    Headquarters, Washington
    202-358-1726
    dwayne.c.brown@nasa.gov

    Nancy Jones / Bill Steigerwald
    Goddard Space Flight Center, Greenbelt, Md.
    301-286-0039 / 301-286-5017
    nancy.n.jones@nasa.gov / william.a.steigerwald@nasa.gov

    NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has provided scientists their first look at a storm of energetic solar particles at Mars, produced unprecedented ultraviolet images of the tenuous oxygen, hydrogen, and carbon coronas surrounding the Red Planet, and yielded a comprehensive map of highly-variable ozone in the atmosphere underlying the coronas.

    stuff
    hree views of an escaping atmosphere, obtained by MAVEN’s Imaging Ultraviolet Spectrograph. By observing all of the products of water and carbon dioxide breakdown, MAVEN’s remote sensing team can characterize the processes that drive atmospheric loss on Mars. Image Credit: University of Colorado/NASA

    NASA MAVEN
    NASA/MAVEN

    The spacecraft, which entered Mars’ orbit Sept. 21, now is lowering its orbit and testing its instruments. MAVEN was launched to Mars in November 2013, to help solve the mystery of how the Red Planet lost most of its atmosphere.

    “All the instruments are showing data quality that is better than anticipated at this early stage of the mission,” said Bruce Jakosky, MAVEN Principal Investigator at the University of Colorado, Boulder. “All instruments have now been turned on — although not yet fully checked out — and are functioning nominally. It’s turning out to be an easy and straightforward spacecraft to fly, at least so far. It really looks as if we’re headed for an exciting science mission.”

    Solar energetic particles (SEPs) are streams of high-speed particles blasted from the sun during explosive solar activity like flares or coronal mass ejections (CMEs). Around Earth, SEP storms can damage the sensitive electronics on satellites. At Mars, they are thought to be one possible mechanism for driving atmospheric loss.

    A solar flare on Sept. 26 produced a CME that was observed by NASA satellites on both sides of the sun. Computer models of the CME propagation predicted the disturbance and the accompanying SEPs would reach Mars on Sept. 29. MAVEN’s Solar Energetic Particle instrument was able to observe the onset of the event that day.

    “After traveling through interplanetary space, these energetic particles of mostly protons deposit their energy in the upper atmosphere of Mars,” said SEP instrument lead Davin Larson of the Space Sciences Laboratory at the University of California, Berkeley. “A SEP event like this typically occurs every couple weeks. Once all the instruments are turned on, we expect to also be able to track the response of the upper atmosphere to them.”

    The hydrogen and oxygen coronas of Mars are the tenuous outer fringe of the planet’s upper atmosphere, where the edge of the atmosphere meets space. In this region, atoms that were once a part of carbon dioxide or water molecules near the surface can escape to space. These molecules control the climate, so following them allows us to understand the history of Mars over the last four billion years and to track the change from a warm and wet climate to the cold, dry climate we see today. MAVEN observed the edges of the Martian atmosphere using the Imaging Ultraviolet Spectrograph (IUVS), which is sensitive to the sunlight reflected by these atoms.

    “With these observations, MAVEN’s IUVS has obtained the most complete picture of the extended Martian upper atmosphere ever made,” said MAVEN Remote Sensing Team member Mike Chaffin of the University of Colorado, Boulder. “By measuring the extended upper atmosphere of the planet, MAVEN directly probes how these atoms escape to space. The observations support our current understanding that the upper atmosphere of Mars, when compared to Venus and Earth, is only tenuously bound by the Red Planet’s weak gravity.”

    IUVS also created a map of the atmospheric ozone on Mars by detecting the absorption of ultraviolet sunlight by the molecule.

    “With these maps we have the kind of complete and simultaneous coverage of Mars that is usually only possible for Earth,” said MAVEN Remote Sensing Team member Justin Deighan of the University of Colorado, Boulder. “On Earth, ozone destruction by refrigerator CFCs is the cause of the polar ozone hole. On Mars, ozone is just as easily destroyed by the byproducts of water vapor breakdown by ultraviolet sunlight. Tracking the ozone lets us track the photochemical processes taking place in the Martian atmosphere. We’ll be exploring this in more complete detail during MAVEN’s primary science mission.”

    There will be about two weeks of additional instrument calibration and testing before MAVEN starts its primary science mission. This includes an end-to-end test to transmit data between NASA’s Curiosity rover on the surface of Mars and Earth using the MAVEN mission’s Electra telecommunications relay. The mission aims to start full science gathering in early to mid-November.

    NASA Mars Curiosity Rover
    NASA/Curiosity

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

    For more about MAVEN, visit:

    http://www.nasa.gov/maven

    See the full article here.

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

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

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

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble,
    Chandra, Spitzer ]and associated programs. NASA shares data with various national and international organizations such as from the Greenhouse Gases Observing Satellite.
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  • richardmitnick 2:46 pm on October 10, 2014 Permalink | Reply
    Tags: , , , , NASA MARS MAVEN   

    From NASA Science: “First Light for MAVEN” 

    NASA Science Science News

    Oct 10, 2014
    Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit: Science@NASA

    After 10-month voyage across more than 400 million miles of empty space, NASA’s MAVEN spacecraft reached Mars on Sept. 21st 2014. Less than 8 hours later, the data started to flow.

    splash

    NASA Mars MAVEN
    NASA MAVEN

    “Our Imaging Ultraviolet Spectrograph (IUVS) obtained these false-color images of Mars on Sept. 22nd,” says Nick Schneider who leads the instrument team at the University of Colorado. “They trace the distribution of hydrogen and oxygen in the Martian atmosphere.”

    MAVEN is on a mission to investigate a planetary mystery. Billions of years ago, Mars was blanketed by an atmosphere massive enough to warm the planet and allow liquid water to flow on its surface. Life could have thrived in such an environment. Today, however, only a tiny fraction of that ancient air remains, leaving Mars a desiccated wasteland.

    What happened to the atmosphere of Mars? MAVEN will attempt to answer the question by studying the upper atmosphere, where gaseous material could be lost to space.

    Schneider explains what the IUVS saw in its first look: “The oxygen gas is held close to the planet by Mars’ gravity, while lighter hydrogen gas expands to higher altitudes and extends past the edges of the image. These gases come from the breakdown of water and carbon dioxide in Mars’ atmosphere.”

    Among researchers, a popular candidate for atmospheric loss is space weather: Eons of solar storms and the relentless buffeting of solar wind might have stripped away much of the Martian atmosphere.

    A CME, or coronal mass ejection, is a billion-ton cloud of ionized gas blasted away from the sun in the aftermath of a solar flare. When CMEs hit Earth, they rattle our planet’s magnetic field, causing Northern Lights and, in extreme cases, power blackouts.

    Unlike Earth, Mars has no global magnetic field to protect it. For the most part, the Martian atmosphere is unshielded. That’s why gusts of solar wind and CME strikes could strip material away.

    “MAVEN’s primary science goal is to see how the atmosphere responds to solar forcing,” says Bruce Jakosky, the Principal Investigator for MAVEN. “So on the one hand, a CME might strip the outermost layers of the atmosphere. On the other, it might also energize the atmosphere below and repopulate the extended atmosphere with a lot of new material.”

    Either way, he says, “we expect to see something.”

    The instrument is also capable of observing Martian auroras. Here on Earth, auroras ring the magnetic poles, north and south. Mars, however, has a different magnetic structure. There is no coherent global magnetic field. Instead, Mars has a patchwork of magnetic umbrellas that sprout out of the surface in hundreds of places all around the planet. If Martian auroras occur, they would appear in the canopies of those umbrellas.

    “We are on the edges of our seats, hoping for our first detection,” says Schneider.

    Having just reached Mars, MAVEN is still in its commissioning phase. Instruments are being checked out, the spacecraft’s orbit is being adjusted. The fact that data are already arriving at Earth is an impressive achievement.

    This is just the beginning. IUVS is only one of three instrument suites on MAVEN. The Neutral Gas and Ion Spectrometer from the Goddard Space Flight Center and the Particles and Fields Package from UC Berkeley will soon be making their own revelations about Mars.

    See the full article here.

    NASA leads the nation on a great journey of discovery, seeking new knowledge and understanding of our planet Earth, our Sun and solar system, and the universe out to its farthest reaches and back to its earliest moments of existence. NASA’s Science Mission Directorate (SMD) and the nation’s science community use space observatories to conduct scientific studies of the Earth from space to visit and return samples from other bodies in the solar system, and to peer out into our Galaxy and beyond. NASA’s science program seeks answers to profound questions that touch us all:

    This is NASA’s science vision: using the vantage point of space to achieve with the science community and our partners a deep scientific understanding of our planet, other planets and solar system bodies, the interplanetary environment, the Sun and its effects on the solar system, and the universe beyond. In so doing, we lay the intellectual foundation for the robotic and human expeditions of the future while meeting today’s needs for scientific information to address national concerns, such as climate change and space weather. At every step we share the journey of scientific exploration with the public and partner with others to substantially improve science, technology, engineering and mathematics (STEM) education nationwide.

    NASA

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