News Article | December 14, 2016
Taken from the December 2016 issue of Physics World Sun Moon Earth: the History of Solar Eclipses from Omens of Doom to Einstein and Exoplanets Tyler Nordgren 2016 Basic Books $26.99hb 256pp On 21 August 2017 a total solar eclipse will cast its sweeping shadow across the US. Starting around 10 a.m. in Oregon on the west coast, it will end all too soon, a mere 90 minutes later in South Carolina in the east. An awe-inspiring cosmic display awaits those who are either lucky enough to live along that swath of land, or who make the effort to get there. Depending on where it’s observed from along its path in the US, totality will last from anywhere between 1 and 2.5 minutes, but for the rest of Northern and Central America, the eclipse will be partial. Nonetheless, the sight of the new Moon forming a dark crescent shadow on the solar surface will be a celestial spectacle for any viewer. In his book Sun Moon Earth: the History of Solar Eclipses from Omens of Doom to Einstein and Exoplanets, author and astronomer Tyler Nordgren charts the evolving history and science of the natural phenomenon that is a solar eclipse. Through a narrative that flows effortlessly between personal experiences and scientific facts, Nordgren – a professor of physics at the University of Redlands in California, US – engages the reader with fascinating scientific discoveries that this cosmic coincidence makes possible. Eclipses are a good reminder that planetary motions follow well-defined laws of physics, for the most part. It is these latter exceptions, when the laws are broken, that have driven some of the most significant discoveries of our time, including the modifications to Newton’s laws of gravitational motion in the form of Albert Einstein’s theory of relativity, which was substantiated thanks to Arthur Eddington’s observations of starlight during the eclipse of 1919. Nordgren also describes just how addictive it can become once you witness a total solar eclipse – see one and you are already planning for the next. Eclipse chasing can become a costly affair as you often travel to remote locations. As a scientist who has been leading a team to observe total solar eclipses since 1995, I understand all too well the eclipse-addiction syndrome. For my group – the Solar Wind Sherpas – an eclipse offers us the unique opportunity to probe a small section of the sun’s corona (of just a few solar radii) that is closest to its surface, which currently cannot be observed by any other instrument. With each eclipse, opportunities arise for testing new ideas and new instrumentation. For the most part, it is the fleeting beauty of this event that makes the experience so compelling. Lasting a maximum possible seven minutes, the magic is always over too soon. The prospect of bad weather – that sometimes looms as a literal dark cloud – is omnipresent and makes observing solar eclipses even more of a challenge. The Solar Wind Sherpas have experienced the entire spectrum of emotion, from utter disappointment when the view was clouded out, to extreme joy when clear skies prevailed. But the addiction persists as we continue to strive to uncover some of the secrets of the Sun and its corona. Astronomers and non-scientists are often equally obsessed with eclipses. But for the former, it is the unique opportunities that a solar eclipse offers – to test certain theories or trial new technologies – that is tempting. Beyond the sheer visual awe of an eclipse, the celestial setting that comprises the Sun, Moon and Earth serves as an excellent laboratory tool. Light is a ubiquitous astronomical signal that can be detected using everything from a telescope to a spectrograph to the naked human eye and has been studied through the centuries. According to Nordgren, the world’s first eclipse-chaser happened to be a scientist – Jacques d’Allonville, or Chevalier de Louville, a member of the Royal Academy of Sciences in Paris – who travelled to London to see the total solar eclipse of 22 April 1715. This eclipse had been predicted by astronomer and mathematician Edmund Halley, using his friend Isaac Newton’s laws of motion. Incidentally, this event was also one of the first times that the public had been asked to engage in the science being done. Halley distributed posters across the country asking people to record the time and duration of the event using their pendulum clocks and to mail him their results. Halley’s aim was to make better measurements of the Moon’s orbit, thereby improving his ability to predict future eclipses. A strikingly similar example of citizen science followed some 200 years later, when a total solar eclipse was predicted to pass over New York City on 24 January 1925. A number of scientists urged the public to witness totality and record the eclipse’s time and duration, in what the New York Times deemed “cosmic detective work.” The book ends by offering the author’s insight into the evolution and the ultimate fate of our Sun and solar system. Nordgren teases us with the basic question, and worry, of whether eclipses will “forever” be present for us to marvel at. Currently, no other planet in our system has the privilege of experiencing a total solar eclipse. Our Sun, Moon and Earth can continue to boast of their unique alignment, but for how long? We can breathe a sigh of relief for now, as this fortuitous combination of sizes, distances and orbits that allows for a total solar eclipse to occur will last for at least the next few hundred million years. Nordgren captures the scientific significance of total solar eclipses in a manner that is readily accessible to most readers. Certain concepts mentioned in the book – including the rather complicated story behind the modification to Newtonian gravity, which could not account for discrepancies in the orbit of Mercury, and eventually led to Einstein’s theory of relativity – might be difficult for some to follow. However, this does not deter the reader from carrying on. Nordgren’s book is extremely timely, and hopefully many of its readers will be compelled to witness the beauty of the corona next year.
News Article | October 26, 2016
Jasper Halekas, associate physics and astronomy professor at the University of Iowa, has won an Exceptional Scientific Achievement Medal from NASA, for "exceptional contributions to MAVEN's science return using the Solar Wind Ion Analyzer (SWIA) instrument." Halekas is the principal investigator on the SWIA instrument, which this month contributed to the finding that hydrogen escape - and thus water loss - from Mars's atmosphere varied dramatically depending on the planet's distance from the sun. This loss had long been assumed to be more or less constant, like a slow leak in a tire. The NASA medal is awarded for exceptional contributions toward the achievement of the NASA mission. NASA awarded only seven Exceptional Scientific Achievement Medals in 2016. In November 2015, NASA announced the MAVEN mission was able to determine the rate at which the Martian atmosphere is currently losing gas to space due to stripping by the solar wind. This may be why Mars's early, warm, wet climate--one that may have been able to support life--changed into its current cold, dry desert climate.
News Article | September 17, 2016
Did you ever notice that Pluto doesn’t have much of a tail? No, not that Pluto! This Pluto: This has been known for a while. NASA noted this last year: New Horizons has discovered a region of cold, dense ionized gas tens of thousands of miles beyond Pluto — the planet’s atmosphere being stripped away by the solar wind and lost to space. Beginning an hour and half after closest approach, the Solar Wind Around Pluto (SWAP) instrument observed a cavity in the solar wind — the outflow of electrically charged particles from the Sun — between 48,000 miles (77,000 km) and 68,000 miles (109,000 km) downstream of Pluto. SWAP data revealed this cavity to be populated with nitrogen ions forming a “plasma tail” of undetermined structure and length extending behind the planet. Not long ago it was not known that Pluto had an atmosphere. But it does, and it is probably made from solid ice that makes up a good portion of the planet. When Pluto is nearer the Sun, this atmosphere burns off and forms an unimpressive tail. (Existentially impressive, but not fireworks impressive.) If Pluto were to come really close to the sun, like a typical comet, it would … well, it would essentially be a a comet. A pretty big one, at first. But then after several passes… Anyway, more recently, it has been discovered that Pluto also puts out X-rays, and if confirmed, this is interesting. The total number of X-rays that have been detected is very small. The existence of these X-rays is likely linked to the atmosphere. From NASA: Scientists using NASA’s Chandra X-ray Observatory have made the first detections of X-rays from Pluto. These observations offer new insight into the space environment surrounding the largest and best-known object in the solar system’s outermost regions. While NASA’s New Horizons spacecraft was speeding toward and beyond Pluto, Chandra was aimed several times on the dwarf planet and its moons, gathering data on Pluto that the missions could compare after the flyby. Each time Chandra pointed at Pluto – four times in all, from February 2014 through August 2015 – it detected low-energy X-rays from the small planet. Pluto is the largest object in the Kuiper Belt, a ring or belt containing a vast population of small bodies orbiting the Sun beyond Neptune. The Kuiper belt extends from the orbit of Neptune, at 30 times the distance of Earth from the Sun, to about 50 times the Earth-Sun distance. Pluto’s orbit ranges over the same span as the overall Kupier Belt. “We’ve just detected, for the first time, X-rays coming from an object in our Kuiper Belt, and learned that Pluto is interacting with the solar wind in an unexpected and energetic fashion,” said Carey Lisse, an astrophysicist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, who led the Chandra observation team with APL colleague and New Horizons Co-Investigator Ralph McNutt. “We can expect other large Kuiper Belt objects to be doing the same.” The team recently published its findings online in the journal Icarus. The report details what Lisse says was a somewhat surprising detection given that Pluto – being cold, rocky and without a magnetic field – has no natural mechanism for emitting X-rays. But Lisse, having also led the team that made the first X-ray detections from a comet two decades ago, knew the interaction between the gases surrounding such planetary bodies and the solar wind – the constant streams of charged particles from the sun that speed throughout the solar system – can create X-rays. New Horizons scientists were particularly interested in learning more about the interaction between the gases in Pluto’s atmosphere and the solar wind. The spacecraft itself carries an instrument designed to measure that activity up-close – the aptly named Solar Wind Around Pluto (SWAP) – and scientists are using that data to craft a picture of Pluto that contains a very mild, close-in bowshock, where the solar wind first “meets” Pluto (similar to a shock wave that forms ahead of a supersonic aircraft) and a small wake or tail behind the planet. The immediate mystery is that Chandra’s readings on the brightness of the X-rays are much higher than expected from the solar wind interacting with Pluto’s atmosphere. “Before our observations, scientists thought it was highly unlikely that we’d detect X-rays from Pluto, causing a strong debate as to whether Chandra should observe it at all,” said co-author Scott Wolk, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “Prior to Pluto, the most distant solar system body with detected X-ray emission was Saturn’s rings and disk.” The Chandra detection is especially surprising since New Horizons discovered Pluto’s atmosphere was much more stable than the rapidly escaping, “comet-like” atmosphere that many scientists expected before the spacecraft flew past in July 2015. In fact, New Horizons found that Pluto’s interaction with the solar wind is much more like the interaction of the solar wind with Mars, than with a comet. However, although Pluto is releasing enough gas from its atmosphere to make the observed X-rays, in simple models for the intensity of the solar wind at the distance of Pluto, there isn’t enough solar wind flowing directly at Pluto to make them. Lisse and his colleagues – who also include SWAP co-investigators David McComas from Princeton University and Heather Elliott from Southwest Research Institute – suggest several possibilities for the enhanced X-ray emission from Pluto. These include a much wider and longer tail of gases trailing Pluto than New Horizons detected using its SWAP instrument. Other possibilities are that interplanetary magnetic fields are focusing more particles than expected from the solar wind into the region around Pluto, or the low density of the solar wind in the outer solar system at the distance of Pluto could allow for the formation of a doughnut, or torus, of neutral gas centered around Pluto’s orbit. That the Chandra measurements don’t quite match up with New Horizons up-close observations is the benefit – and beauty – of an opportunity like the New Horizons flyby. “When you have a chance at a once in a lifetime flyby like New Horizons at Pluto, you want to point every piece of glass – every telescope on and around Earth – at the target,” McNutt says. “The measurements come together and give you a much more complete picture you couldn’t get at any other time, from anywhere else.” New Horizons has an opportunity to test these findings and shed even more light on this distant region – billions of miles from Earth – as part of its recently approved extended mission to survey the Kuiper Belt and encounter another smaller Kuiper Belt object, 2014 MU69, on Jan. 1, 2019. It is unlikely to be feasible to detect X-rays from MU69, but Chandra might detect X-rays from other larger and closer objects that New Horizons will observe as it flies through the Kuiper Belt towards MU69. The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations.
News Article | April 5, 2016
The Solar Wind Around Pluto (SWAP) instrument, operated by Southwest Research Institute (SwRI), collected three years' worth of measurements before the July 15 Pluto flyby. Data showed that the tumultuous flow of solar particles, which in the inner solar system is structured by the interaction of fast and slow flows as well as eruptive events on the Sun, becomes more uniform by the time the solar wind has traversed the 3 billion miles to Pluto's orbit. SWAP measures the solar wind and ions created as the neutral interstellar material becomes ionized and is "picked up" by the solar wind. These interstellar pickup ions can have up to twice the speed and four times the energy of the solar wind. Farther out in space, these ions may be the seeds of the extremely fast energetic particles called anomalous cosmic rays, which pose a radiation threat to astronauts closer to Earth. These ions also play an important role in shaping the boundary where the solar wind hits interstellar space. New Horizons is currently at about 35 astronomical units (about 35 times farther than the Earth to the Sun). It is the only operating spacecraft in the outer solar system. Only Voyager 2 has measured the solar wind farther away from the Sun; however, SWAP on New Horizons will be the first to measure the interstellar pickup ions in the outer solar system. The results will appear in a study to be published April 6 by the Astrophysical Journal Supplement. Lead author Dr. Heather Elliott, a principal scientist in SwRI's Space Science and Engineering Division, said the SWAP instrument was busy even when the rest of New Horizon's instruments were "hibernating" to save energy on the long, nine-year voyage to Pluto. "The instrument was only scheduled to power on for annual checkouts after the Jupiter flyby in 2007," she said. "We came up with a plan to keep the particle instruments on during the cruise phase while the rest of the spacecraft was hibernating. We started observing in 2012." The plan yielded three years of near-continuous observations, capturing detailed measurements of the space environment in a region few spacecraft have ever visited. Because the Sun is the source of the solar wind, events on the Sun are the primary force that shapes the space environment. Shocks in the solar wind—which can produce space weather, such as auroras, on worlds with magnetic fields—are created either by fast, dense clouds of material called coronal mass ejections or by the collision of two different-speed solar wind streams. These individual features are easily observed in the inner solar system, but New Horizons didn't see the same level of detail. "At this distance, the scale size of discernible solar wind structures increases, since smaller structures are worn down or merge together," said Elliott. "It's hard to predict if the interaction between smaller structures will create a bigger structure, or if they will flatten out completely." Subtler signs of the Sun's influence are also harder to spot in the outer solar system. Characteristics of the solar wind—speed, density, and temperature—are shaped by the region of the Sun it flows from. As the Sun and its different wind-producing regions rotate, patterns form. New Horizons didn't see patterns as defined as they are when closer to the Sun, but it nevertheless did spot some structure. "Differences in speed and density average together as the solar wind moves out," said Elliott. "But the wind is still being heated as it travels and faster wind runs into slower wind, so you see evidence of the Sun's rotation pattern in the temperatures even in the outer solar system." New Horizons is the first mission in NASA's New Frontiers program, managed by the agency's Marshall Space Flight Center in Huntsville, Ala. The Johns Hopkins University Applied Physics Laboratory designed, built, and operates the New Horizons spacecraft and manages the mission under Principal Investigator Dr. Alan Stern's direction for NASA's Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning. The NASA Heliophysics program also supported the analysis of these observations. Explore further: Scientists simulate the space environment during New Horizons flyby More information: "New Horizons Solar Wind Around Pluto (SWAP) Observations of the Solar Wind From 11-33 AU," H. A. Elliott et al., 2016, Astrophysical Journal Supplement Series , arxiv.org/abs/1601.07156
News Article | February 24, 2017
GE Renewable Energy has been selected to supply wind and solar components for the first ever US commercial integrated solar-wind hybrid project. While the project is small, it’s nevertheless a good start. The 4.6 megawatt project is a community project set for Red Lake Falls in Minnesota, and to be developed by North American developer Juhl Energy. GE Renewable Energy has been contracted to supply two 2.3-116 wind turbines from GE Renewable Energy’s Onshore Wind business, as well as 1 megawatt (MW) of solar power conversion equipment provided by GE’s Current business. The 4.6 MW project is set to enter commercial operation later this year, and according to GE could be the beginning of a much larger sector. Specifically, GE highlights a report from Global Market Insights that predicts the global market for Hybrid Solar Wind projects could reach as much as $1.47 billion by 2024. The US sector size was already valued at $195 million in 2015, and is expected to reach over $300 million by 2024. The Red Lake Falls project will make use of GE’s Wind Integrated Solar Energy technology platform to properly integrate the solar panels through the wind turbine’s converter so that both wind and solar share all the same balance of plant — a move which GE estimates will increase system net capacity by 3% to 4% and annual energy production by up to 10%. “By leveraging the complementary nature of wind and solar, this unique project shows how GE is driving technology innovation that will help customers deliver more renewable energy in an even more efficient manner,” said Pete McCabe, President & CEO, Onshore Wind, GE Renewable Energy. “Most energy experts agree that distributed generation will play a major role in the implementation of renewable energy in the US electrical market in the years to come,” added Dan Juhl, CEO of Juhl Energy. “Juhl Energy’s package design, with the GE hybrid technology, can economically blend clean, renewable energy into the grid at lower cost, plus add reliability to the system.” Buy a cool T-shirt or mug in the CleanTechnica store! Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech daily newsletter or weekly newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.
News Article | December 13, 2016
University of Iowa scientist to give talk about mini shock waves on the moon at American Gescientist to give talk about mini shock waves on the moon The sonic boom created by an airplane comes from the craft's large, speeding body crashing into molecules in the air. But if you shrank the plane to the size of a molecule, would it still generate a shock wave? Scientists such as University of Iowa physicist Jasper Halekas hope to answer that question by studying miniature shock waves on the moon. These sonic boomlets, physicists believe, are being generated by protons in the solar wind--moving at supersonic speed--colliding with pockets of magnetic fields that bubble up from the moon's crust. Halekas will discuss new findings about the physics underlying the moon's mini shock waves at the American Geophysical Union fall meeting in San Francisco. Halekas's talk, "Kinetic Interactions Between the Solar Wind and Lunar Magnetic Fields," is scheduled for Dec. 14 at 4 p.m. Pacific Standard Time. "We basically don't understand how a magnetic field that small would generate something that we would notice," says Halekas, associate professor in physics and astronomy at the UI. "The general consensus was the solar wind would go right by it." The findings come from NASA's ARTEMIS mission, where two probes circling Earth's nearest celestial neighbor have been gathering high-fidelity measurements of the shock waves. Halekas is the deputy principal investigator on the mission. The moon's magnetic fields first were measured by astronauts beginning with the Apollo 12 mission in 1969. Their portable magnetometers recorded magnetic intensities that varied by location; yet, the highest recorded result was just 1 percent the magnetic field strength on Earth. Despite the fields' weakness and small size, spacecraft since then have documented the solar wind-magnetic field collisions, called "limb shocks," at the boundary between the moon's light side--the side facing the sun--and its dark side. Those collisions produce a reflected plume of sorts that radiates from the moon, similar to ripples on a pond. ARTEMIS has made 40 observations of the shock waves, Halekas says. Scientists want to better understand how these mini shock waves are created, as they may occur elsewhere in the solar system. For example, localized shock waves may occur as the solar wind blows by asteroids, Halekas says. It would be important to know about how it all works before trying to land astronauts on a zooming block of rock, as NASA has said it wants to do. The moon is a good place to study the phenomenon. "They may represent the smallest shock waves in our solar system," Halekas says, "and perhaps even the smallest shock waves that can be formed." In a related talk, UI graduate student Stephanie Howard will discuss the ripples that radiate from where the solar wind collides with the lunar magnetic fields. It's the first presentation at a major scientific meeting for Howard, who is in her third year of doctoral studies. "It was a big surprise to me when I found out I would be giving a talk instead of just presenting a poster," she says. "But I think it'll be a great opportunity to meet and present my own research to others who work in the same field."
News Article | January 21, 2017
NASA's New Horizons made history when it flew through the Pluto system in 2015. Now, the space agency is offering a look into what it would have been like had the spacecraft landed on the dwarf planet. In a video posted Jan. 20, NASA created a movie that allowed viewers to feel as if they were diving into Pluto. To do this, mission scientists interpolated some of the black and white images captured by New Horizons based on what is their best idea of what the planet looks like. Low-resolution color from the spacecraft's Ralph / Multispectral Visual Imaging Camera was then laid over the frames to give the best available color simulation of the view you'd have if you were descending to Pluto from a high altitude. On the same day, NASA released a new, detailed global mosaic color map for Pluto based on three color filter images captured by the Ralph camera during New Horizon's close flyby to the planet. The mosaic features color patterns extending beyond the hemisphere toward New Horizons at the spacecraft's closest approach, as well as the Sputnik Planitia glacier, which shows the left half of Pluto's "heart" in the center. It took New Horizons 9.5 years and over 3 billion miles to get to the Pluto system, getting as close as 7,800 miles of the planet on July 14, 2015. As the spacecraft was fitted with telescopic cameras powerful enough to spot features smaller in size than a football field, it was able to capture and send back hundreds of images of Pluto and its moons, many showing how fascinating and dynamic their surfaces are. On Oct. 25, the last set of data from New Horizons was downloaded at the Johns Hopkins Applied Physics Laboratory after passing through the NASA Deep Space Network station located in Canberra, Australia. With that, the spacecraft had sent a total of over 50 gigabits of data over the course of 15 months. "The Pluto system data that New Horizons collected has amazed us over and over again with the beauty and complexity of Pluto and its system of moons," said Alan Stern, principal investigator for New Horizons. As part of an extended mission, there are plans to have New Horizons head farther into the Kuiper Belt to take a look at what's out there billions of miles beyond Neptune. Where it exactly goes until 2020 will depend on approval from NASA. The United States is the first country to reach every planet between Mercury and Neptune via a space probe, and New Horizons is allowing the nation to complete its initial reconnaissance of the solar system. Aside from the Ralph camera that is a visible and infrared light imager, science payloads aboard the New Horizons spacecraft include: the Alice ultraviolet imaging spectrometer, REX (Radio Science EXperiment) passive radiometer, LORRI (Long Range Reconnaissance Imager) telescopic camera, SWAP (Solar Wind Around Pluto) wind and plasma spectrometer, PEPSSI (Pluto Energetic Particle Spectrometer Science Investigation) energetic particle spectrometer, and VBSDC (Venetia Burney Student Dust Counter) for measuring space dust. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.
News Article | October 26, 2016
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. "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. 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. Lockheed Martin built the spacecraft and is responsible for mission operations. The University of California at Berkeley's Space Sciences Laboratory also provided four science instruments for the mission. 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.
News Article | March 8, 2016
NASA recently selected a miniaturized version of the original X-ray camera to fly as a CubeSat mission to study Earth's magnetic cusps - regions in the magnetic cocoon around our planet near the poles where the magnetic field lines dip down toward the ground. The CubeSat will observe the cusps via soft X-rays emitted when the million-mile-an-hour flow of solar particles constantly streaming from the sun, called the solar wind, collides with and exchanges charges with atoms in the uppermost region of Earth's atmosphere and neutral gases in interplanetary space. The bread loaf-size instrument is the latest incarnation of the Sheath Transport Observer for the Redistribution of Mass, or STORM. Funded by NASA's Heliophysics Technology and Instrument Development for Science, or H-TIDeS program, this new version of the instrument is being developed as WASP/CuPID, short for Wide Angle Soft x-ray Planetary camera and the Cusp Plasma Imaging Detector. The mission is expected to launch in 2019. Three years ago, a team of three NASA scientists at NASA's Goddard Space Flight Center in Greenbelt, Maryland, demonstrated STORM aboard a Black Brant IX sounding rocket to prove that their concept for studying charge exchange would work. The charge-exchange process happens when the heavy ions in the solar wind steal an electron from the neutrals—an exchange that puts the heavy ions in a short-lived excited state. As they relax, they emit soft X-rays. The neutrals from which the heavy ions stole the electron are now charged themselves. This allows them to be picked up by the solar wind and carried away. This is one way planets like Mars could lose their atmosphere. So valuable was the resulting data that the three scientists decided to miniaturize STORM and compete for a CubeSat flight opportunity. Now about half the size of STORM, CuPID/WASP was demonstrated aboard a Black Brant IX sounding rocket in December 2015 and will be further refined under the H-TIDeS funding. Ultimately, it will carry its own avionics system. "Actually, it was quite a coup," said Michael Collier, a planetary scientist who worked with heliophysicist David Sibeck and astrophysicist Scott Porter to develop all instrument versions. "This imager has applications across many different fields and platforms. We figured we could miniaturize it and put it on a CubeSat and still get good science." Boston University professor Brian Walsh, a former Goddard post-doctorate student, is serving as the mission's principal investigator. Like its predecessor, CuPID/WASP employs what's known as a lobster-eye optic, a thick curved slab of material dotted with tiny tubes across the surface. X-ray light enters these tubes from multiple angles and is focused through reflection, giving the technology a wide field of view necessary for globally imaging the emission of soft X-rays. Because the instrument is considerably smaller than STORM, its collecting area isn't quite as good. However, the data is just as valuable to scientists, Porter said. Since its discovery in the mid-1990s, scientists have observed the emission of charge-exchange X-rays from planets, the moon, comets, interplanetary space, possible supernova remnants, and galactic halos. Planetary scientists have observed these emissions from the outer atmospheres of Venus and Mars, leading some to question whether the charge-exchange phenomenon contributes to the atmospheric loss on Mars. Heliophysicists studying how near-Earth space is affected by radiation and magnetic energy from the sun also have observed soft X-rays from the outer boundaries of Earth's magnetosphere, the magnetic bubble that shields Earth from hazardous solar storms. And astrophysicists have observed them, too—as unwanted noise in data collected by all X-ray observatories sensitive to soft X-rays. As a result, planetary scientists and heliophysicists want to measure these emissions for scientific reasons, while astrophysicists want to remove them as noise. Since the instrument's debut in 2012 and subsequent miniaturization as a CubeSat payload, a European-led team has begun considering developing a STORM-like instrument for its proposed Solar Wind Magnetosphere Ionosphere Link Explorer (SMILE). "Everyone is interested in getting this data, although for different reasons," Collier added. "These missions span three different disciplines, which is a rare occurrence in space science."
News Article | November 14, 2016
OCEAN VIEW, Delaware, November 14, 2016 /PRNewswire/ -- Hybrid Solar Wind Market size is expected to reach USD 1.47 billion by 2024, according to a new research report by Global Market Insights, Inc. (Logo: http://photos.prnewswire.com/prnh/20160418/799556-a ) D...