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News Article | April 8, 2016
Site: motherboard.vice.com

YELLOWKNIFE, NWT: I would meet James in the evening, after dinner at around 9pm, when it was still light and felt more like six or seven. We would drive out somewhere as we talked, James taking me to see the old gold mines on the edge of town with their ‘danger’ and ‘open pit’ signs, discarded foreign materials—a piece of long black tubing here, a rusting metal stump there—in a dune-like landscape of rocky, grey rubble grown over with small trees, bushes and purple fireweed that slowly gave way to the solid rock of the Precambrian Canadian Shield. Or we would head out to a small lake surrounded by low trees, where in the winter, James said, the aurora would dance above them. The cirrus clouds and smoky air lent a mottled purplish-blue to the sky as I took a photograph of James, standing solidly in a wide stance, with arms folded across his blue-striped polo shirt, and smiling. He had a kind face with dark hair and a small, neat beard and wore thin glasses that I could barely see from where I stood. In the picture the lines of cirrus almost mirrored the lake’s ripples and the water took on a faint pinkish hue. Or we would go to a Tim Hortons drive-through for coffee, despite it being 10pm, just because, as James said, it’s a Canadian institution. James Pugsley is an amateur astronomer, ex-journalist, government employee and president of Astronomy North, a volunteer organization for education and outreach about the northern skies. The far northern, or southern, sky can be very different to that shown in textbooks based on lower latitudes. The most obvious difference is the view of the Sun. High latitudes see dramatic seasonal effects like long, sometimes endless, summer days and dark winters. The view of the Moon and the stars is also different. Around the shoulders of the solstice, a month or so either side, sky watchers may be treated to a display of noctilucent clouds—bright blue wisps of extremely high-altitude ice crystals reflecting light from the newly set sun into the twilight sky. Then from September to May there is the aurora, and James will be out with his cameras. James runs the AuroraMAX project, a collaboration between Eric Donovan’s team at the University of Calgary, the Canadian Space Agency, the City of Yellowknife and the Astronomy North Society. It is an outreach initiative that aims to show the splendour of the northern lights, raise awareness of the science and also showcase Canada’s scientific interest in the aurora and some of the leading projects like THEMIS. James gathers data to show the intensity and frequency of the northern lights and to demonstrate that they are not just an occasional thing for Yellowknifers. The aurora is happening almost every night. ‘We have consistently seen substorm activity above Yellowknife whether there’s an active sun or not.’ James told me. Yellowknife is in a prime spot and is often described as the best place in the world to see the aurora. It is the unique combination of perfect magnetic latitude and arid climate. It sits right in the auroral zone in the centre of a continent and in the rain shadow of the Mackenzie Mountains to the west. Consequently it has mostly clear nights, perfect for aurora viewing. Initially the aim of AuroraMAX was to connect a Canadian audience with what was going on in their back yard, but a side benefit is that they showcase their aurora to the world, broadcasting the display above Yellowknife via the Internet every night from September to May. The AuroraMAX website gets more than 13 million hits over the course of the winter, and on the Canadian Space Agency site the page that gets the most hits by a long way is the AuroraMAX page. People just love the aurora. Excerpted from Aurora: In Search of the Northern Lights by Melanie Windridge. Copyright © 2016 by Melanie Windridge. Published by William Collins of HarperCollinsPublishers. All Rights Reserved.


News Article | August 24, 2016
Site: www.chromatographytechniques.com

Seasonal dark streaks on Mars that have become one of the hottest topics in interplanetary research don't hold much water, according to the latest findings from a NASA spacecraft orbiting Mars. The new results from NASA's Mars Odyssey mission rely on ground temperature, measured by infrared imaging using the spacecraft's Thermal Emission Imaging System (THEMIS). They do not contradict last year's identification of hydrated salt at these flows, which since their 2011 discovery have been regarded as possible markers for the presence of liquid water on modern Mars. However, the temperature measurements now identify an upper limit on how much water is present at these darkened streaks: about as much as in the driest desert sands on Earth. When water is present in the spaces between particles of soil or grains of sand, it affects how quickly a patch of ground heats up during the day and cools off at night. "We used a very sensitive technique to quantify the amount of water associated with these features," said Christopher Edwards of Northern Arizona University, Flagstaff. "The results are consistent with no moisture at all and set an upper limit at three percent water." The features, called recurring slope lineae or RSL, have been identified at dozens of sites on Mars. A darkening of the ground extends downhill in fingerlike flows during spring or summer, fades away in fall and winter, then repeats the pattern in another year at the same location. The process that causes the streaks to appear is still a puzzle. "Some type of water-related activity at the uphill end still might be a factor in triggering RSL, but the darkness of the ground is not associated with large amounts of water, either liquid or frozen," Edwards said. "Totally dry mechanisms for explaining RSL should not be ruled out." He and Sylvain Piqueux of NASA's Jet Propulsion Laboratory, Pasadena, California, analyzed several years of THEMIS infrared observations of a crater-wall region within the large Valles Marineris canyon system on Mars. Numerous RSL features sit close together in some parts of the study region. Edwards and Piqueux compared nighttime temperatures of patches of ground averaging about 44 percent RSL features, in the area, to temperatures of nearby slopes with no RSL. They found no detectable difference, even during seasons when RSL were actively growing. The report of these findings by Edwards and Piqueux has been accepted by the peer-reviewed Geophysical Research Letters and is available online. There is some margin of error in assessing ground temperatures with the multiple THEMIS observations used in this study, enough to leave the possibility that the RSL sites differed undetectably from non-RSL sites by as much as 1.8 degrees Fahrenheit (1 Celsius degree). The researchers used that largest possible difference to calculate the maximum possible amount of water -- either liquid or frozen -- in the surface material. How deeply moisture reaches beneath the surface, as well as the amount of water present right at the surface, affects how quickly the surface loses heat. The new study calculates that if RSL have only a wafer-thin layer of water-containing soil, that layer contains no more than about an ounce of water per two pounds of soil (3 grams water per kilogram of soil). That is about the same concentration of water as in the surface material of the Atacama Desert and Antarctic Dry Valleys, the driest places on Earth. If the water-containing layer at RSL is thicker, the amount of water per pound or kilogram of soil would need to be even less, to stay consistent with the temperature measurements. Research published last year identified hydrated salts in the surface composition of RSL sites, with an increase during the season when streaks are active. Hydrated salts hold water molecules affecting the crystalline structure of the salt. "Our findings are consistent with the presence of hydrated salts, because you can have hydrated salt without having enough for the water to start filling pore spaces between particles," Edwards said. "Salts can become hydrated by pulling water vapor from the atmosphere, with no need for an underground source of the water." "Through additional data and studies, we are learning more about these puzzling seasonal features -- narrowing the range of possible explanations," said Michael Meyer. “It just shows us that we still have much to learn about Mars and its potential as a habitat for life." The new study touches on additional factors that add to understanding of RSL. -- If RSL were seasonal flows of briny water followed by evaporation, annual buildup of crust-forming salt should affect temperature properties. So the lack of a temperature difference between RSL and non-RSL sites is evidence against evaporating brines. -- Lack of a temperature difference is also evidence against RSL being cascades of dry material with different thermal properties than the pre-existing slope material, such as would be the case with annual avalanching of powdery dust that accumulates from dusty air. Arizona State University, Tempe, provided and operates the THEMIS camera, which records observations in both infrared and visible-light wavelengths. JPL, a division of Caltech, manages the Mars Odyssey project for NASA. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it.


News Article | September 12, 2016
Site: phys.org

Using data from NASA's Time History of Events and Macroscale Interactions during Substorms, or THEMIS, scientists have observed Earth's vibrating magnetic field in relation to the northern lights dancing in the night sky over Canada. THEMIS is a five-spacecraft mission dedicated to understanding the processes behind auroras, which erupt across the sky in response to changes in Earth's magnetic environment, called the magnetosphere. These new observations allowed scientists to directly link specific intense disturbances in the magnetosphere to the magnetic response on the ground. A paper on these findings was published in Nature Physics on Sept. 12, 2016. "We've made similar observations before, but only in one place at a time - on the ground or in space," said David Sibeck, THEMIS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who did not participate in the study. "When you have the measurements in both places, you can relate the two things together." Understanding how and why auroras occur helps us learn more about the complex space environment around our planet. Radiation and energy in near-Earth space can have a variety of effects on our satellites - from disrupting their electronics to increasing frictional drag and interrupting communication or navigation signals. As our dependence on GPS grows and space exploration expands, accurate space weather forecasting becomes ever more important. The space environment of our entire solar system, both near Earth and far beyond Pluto, is determined by the sun's activity, which cycles and fluctuates through time. The solar system is filled with solar wind, the constant flow of charged particles from the sun. Most of the solar wind is deflected from Earth by our planet's protective magnetosphere. However, under the right conditions, some solar particles and energy can penetrate the magnetosphere, disturbing Earth's magnetic field in what's known as a substorm. When the solar wind's magnetic field turns southward, the dayside, or sun-facing side, of the magnetosphere contracts inward. The back end, called the magnetotail, stretches out like a rubber band. When the stretched magnetotail finally snaps back, it starts to vibrate, much like a spring moving back and forth. Bright auroras can occur during this stage of the substorm. In this unstable environment, electrons in near-Earth space stream rapidly down magnetic field lines towards Earth's poles. There, they interact with oxygen and nitrogen particles in the upper atmosphere, releasing photons to create swaths of light that snake across the sky. To map the auroras' electric dance, the scientists imaged the brightening and dimming aurora over Canada with all-sky cameras. They simultaneously used ground-based magnetic sensors across Canada and Greenland to measure electrical currents during the geomagnetic substorm. Further out in space, the five THEMIS probes were well-positioned to collect data on the motion of the disrupted field lines. The scientists found the aurora moved in harmony with the vibrating field line. Magnetic field lines oscillated in a roughly six-minute cycle, or period, and the aurora brightened and dimmed at the same pace. "We were delighted to see such a strong match," said Evgeny Panov, lead author and researcher at the Space Research Institute of the Austrian Academy of Sciences in Graz. "These observations reveal the missing link in the conversion of magnetic energy to particle energy that powers the aurora." The brightening and dimming of the aurora corresponds to the motion of the electrons and magnetic field lines. "During the course of this event, the electrons are flinging themselves Earthwards, then bouncing back off the magnetosphere, then flinging themselves back," Sibeck said. When waves crash on the beach, they splash and froth, and then recede. The wave of electrons adopt a similar motion. The aurora brightens when the wave of electrons slams into the upper atmosphere, and dims when it ricochets off. Before this study, scientists hypothesized that oscillating magnetic field lines guide the aurora. But the effect had not yet been observed because it requires the THEMIS probes to be located in just the right place over the ground-based sensors, to properly coordinate the data. In this study, scientists collected THEMIS data at a time when the probes were fortuitously positioned to observe the substorm. "Even after nearly 10 years, the probes are still in great health, and the growing network of magnetometers and all-sky cameras continue to generate high quality data," said Vassilis Angelopoulos, co-author and THEMIS principal investigator at University of California, Los Angeles. THEMIS is a mission of NASA's Explorer program, which is managed by Goddard. University of California, Berkeley's Space Sciences Laboratory oversees mission operations. The all-sky imagers and magnetometers are jointly operated by UC Berkeley, UCLA, University of Calgary and University of Alberta in Canada. "The intention with THEMIS has always been that we would put these measurements together and make these observations," Sibeck said. "This is an extremely satisfying study and a pleasure to see the right use of this mission data." More information: E. V. Panov et al. Magnetotail energy dissipation during an auroral substorm, Nature Physics (2016). DOI: 10.1038/nphys3879


News Article | August 30, 2016
Site: www.techtimes.com

Mars, otherwise known as the Red Planet, is a dry and barren place with no clear signs of life. There have been several signs of liquid water on the planet, the latest being a weird and dark streak NASA's Mars Reconnaissance Orbiter came across not too long ago. Should liquid water ever be found on Mars, it would be a huge deal. This is because researchers could locate potential life forms and resources that can be used to make lives better for humanity. However, nothing is ever what it seems at times. As it turns out, researchers are saying, there isn't enough water via those dark streaks as previously hoped. Furthermore, researchers are almost certain that whatever is there, it's not drinkable. To make matters worse, researchers claim the amount of water on Mars cannot exceed that of Earth's driest desert. That's a huge blow to anyone hoping to come across huge swaths of liquid water on the Red Planet's surface. How do scientists come to the conclusion that there isn't much water on the surface of Mars? Well, they used Mars Odyssey's Thermal Emission Imaging System (THEMIS) to monitor the planet's surface from orbit. This is done remotely of course. We understand that whenever water is available between the grain of sand and soil, the temperature on the ground does not heat up as quickly compared to when there's no water available. The deeper the seeps, the more cloistered the ground becomes. Furthermore, after years of analyzing the data from THEMIS, NASA scientists concluded that the soil could only hold just 3 percent of water. That's basically similar levels of dryness found in the driest desert on our planet, the Atacama Desert. "Our findings are consistent with the presence of hydrated salts, because you can have hydrated salt without having enough for the water to start filling pore spaces between particles," said Christopher Edwards, a faculty member in the Department of Physics and Astronomy at Northern Arizona University, in a statement. "Salts can become hydrated by pulling water vapor from the atmosphere, with no need for an underground source of the water." What does this mean? Well, we may have to cease from hoping of ever finding large amounts of water on Mars if these findings turn out to be completely accurate. And with that, it also means we may have to do away with any thought of eve finding life on the planet. Just a little bit of water can be home to life, but the prospects of finding life truly rest on finding large amounts, and this is becoming highly unlikely as time goes by. © 2016 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | November 14, 2016
Site: www.eurekalert.org

High above the surface, Earth's magnetic field constantly deflects incoming supersonic particles from the sun. These particles are disturbed in regions just outside of Earth's magnetic field - and some are reflected into a turbulent region called the foreshock. New observations from NASA's THEMIS mission show that this turbulent region can accelerate electrons up to speeds approaching the speed of light. Such extremely fast particles have been observed in near-Earth space and many other places in the universe, but the mechanisms that accelerate them have not yet been concretely understood. The new results provide the first steps towards an answer, while opening up more questions. The research finds electrons can be accelerated to extremely high speeds in a region farther from Earth than previously thought possible - leading to new inquiries about what causes the acceleration. These findings may change the accepted theories on how electrons can be accelerated not only in shocks near Earth, but also throughout the universe. Having a better understanding of how particles are energized will help scientists and engineers better equip spacecraft and astronauts to deal with these particles, which can cause equipment to malfunction and affect space travelers. "This affects pretty much every field that deals with high-energy particles, from studies of cosmic rays to solar flares and coronal mass ejections, which have the potential to damage satellites and affect astronauts on expeditions to Mars," said Lynn Wilson, lead author of the paper on these results at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The results, published in Physical Review Letters on Nov. 14, 2016, describe how such particles may get accelerated in specific regions just beyond Earth's magnetic field. Typically, a particle streaming toward Earth first encounters a boundary region known as the bow shock, which forms a protective barrier between the sun and Earth. The magnetic field in the bow shock slows the particles, causing most to be deflected away from Earth, though some are reflected back towards the sun. These reflected particles form a region of electrons and ions called the foreshock region. Some of those particles in the foreshock region are highly energetic, fast moving electrons and ions. Historically, scientists have thought one way these particles get to such high energies is by bouncing back and forth across the bow shock, gaining a little extra energy from each collision. However, the new observations suggest the particles can also gain energy through electromagnetic activity in the foreshock region itself. The observations that led to this discovery were taken from one of the THEMIS - short for Time History of Events and Macroscale Interactions during Substorms - mission satellites. The five THEMIS satellites circled Earth to study how the planet's magnetosphere captured and released solar wind energy, in order to understand what initiates the geomagnetic substorms that cause aurora. The THEMIS orbits took the spacecraft across the foreshock boundary regions. The primary THEMIS mission concluded successfully in 2010 and now two of the satellites collect data in orbit around the moon. Operating between the sun and Earth, the spacecraft found electrons accelerated to extremely high energies. The accelerated observations lasted less than a minute, but were much higher than the average energy of particles in the region, and much higher than can be explained by collisions alone. Simultaneous observations from the Wind and STEREO spacecraft showed no solar radio bursts or interplanetary shocks, so the high-energy electrons did not originate from solar activity. "This is a puzzling case because we're seeing energetic electrons where we don't think they should be, and no model fits them," said David Sibeck, co-author and THEMIS project scientist at NASA Goddard. "There is a gap in our knowledge, something basic is missing." The electrons also could not have originated from the bow shock, as had been previously thought. If the electrons were accelerated in the bow shock, they would have a preferred movement direction and location - in line with the magnetic field and moving away from the bow shock in a small, specific region. However, the observed electrons were moving in all directions, not just along magnetic field lines. Additionally, the bow shock can only produce energies at roughly one tenth of the observed electrons' energies. Instead, the cause of the electrons' acceleration was found to be within the foreshock region itself. "It seems to suggest that incredibly small scale things are doing this because the large scale stuff can't explain it," Wilson said. High-energy particles have been observed in the foreshock region for more than 50 years, but until now, no one had seen the high-energy electrons originate from within the foreshock region. This is partially due to the short timescale on which the electrons are accelerated, as previous observations had averaged over several minutes, which may have hidden any event. THEMIS gathers observations much more quickly, making it uniquely able to see the particles. Next, the researchers intend to gather more observations from THEMIS to determine the specific mechanism behind the electrons' acceleration.


News Article | November 14, 2016
Site: phys.org

The new results provide the first steps towards an answer, while opening up more questions. The research finds electrons can be accelerated to extremely high speeds in a region farther from Earth than previously thought possible - leading to new inquiries about what causes the acceleration. These findings may change the accepted theories on how electrons can be accelerated not only in shocks near Earth, but also throughout the universe. Having a better understanding of how particles are energized will help scientists and engineers better equip spacecraft and astronauts to deal with these particles, which can cause equipment to malfunction and affect space travelers. "This affects pretty much every field that deals with high-energy particles, from studies of cosmic rays to solar flares and coronal mass ejections, which have the potential to damage satellites and affect astronauts on expeditions to Mars," said Lynn Wilson, lead author of the paper on these results at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The results, published in Physical Review Letters on Nov. 14, 2016, describe how such particles may get accelerated in specific regions just beyond Earth's magnetic field. Typically, a particle streaming toward Earth first encounters a boundary region known as the bow shock, which forms a protective barrier between the sun and Earth. The magnetic field in the bow shock slows the particles, causing most to be deflected away from Earth, though some are reflected back towards the sun. These reflected particles form a region of electrons and ions called the foreshock region. Some of those particles in the foreshock region are highly energetic, fast moving electrons and ions. Historically, scientists have thought one way these particles get to such high energies is by bouncing back and forth across the bow shock, gaining a little extra energy from each collision. However, the new observations suggest the particles can also gain energy through electromagnetic activity in the foreshock region itself. The observations that led to this discovery were taken from one of the THEMIS - short for Time History of Events and Macroscale Interactions during Substorms - mission satellites. The five THEMIS satellites circled Earth to study how the planet's magnetosphere captured and released solar wind energy, in order to understand what initiates the geomagnetic substorms that cause aurora. The THEMIS orbits took the spacecraft across the foreshock boundary regions. The primary THEMIS mission concluded successfully in 2010 and now two of the satellites collect data in orbit around the moon. Operating between the sun and Earth, the spacecraft found electrons accelerated to extremely high energies. The accelerated observations lasted less than a minute, but were much higher than the average energy of particles in the region, and much higher than can be explained by collisions alone. Simultaneous observations from the Wind and STEREO spacecraft showed no solar radio bursts or interplanetary shocks, so the high-energy electrons did not originate from solar activity. "This is a puzzling case because we're seeing energetic electrons where we don't think they should be, and no model fits them," said David Sibeck, co-author and THEMIS project scientist at NASA Goddard. "There is a gap in our knowledge, something basic is missing." The electrons also could not have originated from the bow shock, as had been previously thought. If the electrons were accelerated in the bow shock, they would have a preferred movement direction and location - in line with the magnetic field and moving away from the bow shock in a small, specific region. However, the observed electrons were moving in all directions, not just along magnetic field lines. Additionally, the bow shock can only produce energies at roughly one tenth of the observed electrons' energies. Instead, the cause of the electrons' acceleration was found to be within the foreshock region itself. "It seems to suggest that incredibly small scale things are doing this because the large scale stuff can't explain it," Wilson said. High-energy particles have been observed in the foreshock region for more than 50 years, but until now, no one had seen the high-energy electrons originate from within the foreshock region. This is partially due to the short timescale on which the electrons are accelerated, as previous observations had averaged over several minutes, which may have hidden any event. THEMIS gathers observations much more quickly, making it uniquely able to see the particles. Next, the researchers intend to gather more observations from THEMIS to determine the specific mechanism behind the electrons' acceleration. Explore further: THEMIS sees Auroras move to the rhythm of Earth's magnetic field


News Article | November 15, 2016
Site: www.sciencedaily.com

High above the surface, Earth's magnetic field constantly deflects incoming supersonic particles from the sun. These particles are disturbed in regions just outside of Earth's magnetic field -- and some are reflected into a turbulent region called the foreshock. New observations from NASA's THEMIS mission show that this turbulent region can accelerate electrons up to speeds approaching the speed of light. Such extremely fast particles have been observed in near-Earth space and many other places in the universe, but the mechanisms that accelerate them have not yet been concretely understood. The new results provide the first steps towards an answer, while opening up more questions. The research finds electrons can be accelerated to extremely high speeds in a region farther from Earth than previously thought possible -- leading to new inquiries about what causes the acceleration. These findings may change the accepted theories on how electrons can be accelerated not only in shocks near Earth, but also throughout the universe. Having a better understanding of how particles are energized will help scientists and engineers better equip spacecraft and astronauts to deal with these particles, which can cause equipment to malfunction and affect space travelers. "This affects pretty much every field that deals with high-energy particles, from studies of cosmic rays to solar flares and coronal mass ejections, which have the potential to damage satellites and affect astronauts on expeditions to Mars," said Lynn Wilson, lead author of the paper on these results at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The results, published in Physical Review Letters on Nov. 14, 2016, describe how such particles may get accelerated in specific regions just beyond Earth's magnetic field. Typically, a particle streaming toward Earth first encounters a boundary region known as the bow shock, which forms a protective barrier between the sun and Earth. The magnetic field in the bow shock slows the particles, causing most to be deflected away from Earth, though some are reflected back towards the sun. These reflected particles form a region of electrons and ions called the foreshock region. Some of those particles in the foreshock region are highly energetic, fast moving electrons and ions. Historically, scientists have thought one way these particles get to such high energies is by bouncing back and forth across the bow shock, gaining a little extra energy from each collision. However, the new observations suggest the particles can also gain energy through electromagnetic activity in the foreshock region itself. The observations that led to this discovery were taken from one of the THEMIS -- short for Time History of Events and Macroscale Interactions during Substorms -- mission satellites. The five THEMIS satellites circled Earth to study how the planet's magnetosphere captured and released solar wind energy, in order to understand what initiates the geomagnetic substorms that cause aurora. The THEMIS orbits took the spacecraft across the foreshock boundary regions. The primary THEMIS mission concluded successfully in 2010 and now two of the satellites collect data in orbit around the moon. Operating between the sun and Earth, the spacecraft found electrons accelerated to extremely high energies. The accelerated observations lasted less than a minute, but were much higher than the average energy of particles in the region, and much higher than can be explained by collisions alone. Simultaneous observations from the Wind and STEREO spacecraft showed no solar radio bursts or interplanetary shocks, so the high-energy electrons did not originate from solar activity. "This is a puzzling case because we're seeing energetic electrons where we don't think they should be, and no model fits them," said David Sibeck, co-author and THEMIS project scientist at NASA Goddard. "There is a gap in our knowledge, something basic is missing." The electrons also could not have originated from the bow shock, as had been previously thought. If the electrons were accelerated in the bow shock, they would have a preferred movement direction and location -- in line with the magnetic field and moving away from the bow shock in a small, specific region. However, the observed electrons were moving in all directions, not just along magnetic field lines. Additionally, the bow shock can only produce energies at roughly one tenth of the observed electrons' energies. Instead, the cause of the electrons' acceleration was found to be within the foreshock region itself. "It seems to suggest that incredibly small scale things are doing this because the large scale stuff can't explain it," Wilson said. High-energy particles have been observed in the foreshock region for more than 50 years, but until now, no one had seen the high-energy electrons originate from within the foreshock region. This is partially due to the short timescale on which the electrons are accelerated, as previous observations had averaged over several minutes, which may have hidden any event. THEMIS gathers observations much more quickly, making it uniquely able to see the particles. Next, the researchers intend to gather more observations from THEMIS to determine the specific mechanism behind the electrons' acceleration.


News Article | April 6, 2016
Site: phys.org

This week 15 years ago, NASA launched a spacecraft with the name 2001 Mars Odyssey, and onboard was the Thermal Emission Imaging System (THEMIS), a multi-wavelength camera designed at Arizona State University.


News Article | September 12, 2016
Site: www.sciencedaily.com

For the first time, scientists have directly mapped Earth's fluctuating magnetic field and resulting electrical currents to aurora, thanks to northern lights observations from NASA's THEMIS mission.


News Article | November 16, 2016
Site: news.yahoo.com

Some electrons are speeding above Earth's surface at nearly the speed of light, and NASA isn't sure why. According to a new study, the tiny, charged particles were found accelerating to high speeds in an unexpected part of space, farther from Earth than previously realized. The region these fast electrons were found in, known as the foreshock, is the part of the solar system where charged particles streaming from the sun are thought to be reflected back from Earth's magnetic field toward the star. SEE ALSO: NASA is firing lasers on Mars — here’s why Until now, however, scientists didn't think the region could speed up particles to the degree that was observed “This is a puzzling case because we’re seeing energetic electrons where we don’t think they should be, and no model fits them,” David Sibeck, a co-author of the new study published in the journal Physical Review Letters said in a statement. “There is a gap in our knowledge, something basic is missing,” Sibeck said. The study evaluated data from a NASA program known as THEMIS — a mission involving five identical space probes tasked with studying Earth’s auroras and the radiation environment around our planet. Charged particles streaming from the sun out into the rest of the solar system can harm satellites in orbit and even people living in space. That radiation needs to be understood in order to guard against its worst effects. “This affects pretty much every field that deals with high-energy particles, from studies of cosmic rays to solar flares and coronal mass ejections, which have the potential to damage satellites and affect astronauts on expeditions to Mars,” Lynn Wilson, another author of the study, said in the statement. Charged particles speeding toward Earth from the sun encounter an area of space called the "bow shock." That region is something like a protective zone that helps shield our planet from the solar wind. The bow shock has a magnetic field within it, which slows high-energy particles down, according to NASA. Most of those particles are diverted away from Earth, but some do bounce back toward the sun, creating the foreshock region, where the electron superhighway was discovered. Before this new research, scientists knew that electrons in the foreshock could move quickly. Researchers have suggested that the particles speed up when they move across the bow shock multiple times, NASA said. But the new study has added to NASA's understanding of how these electrons accelerate. It seems as though some kind of electromagnetic activity in the foreshock itself might be accelerating the particles to unexpected speeds, the study suggests.

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