Mars Proton Aurora

Comparison of normal and patchy proton aurora formation mechanisms at Mars. Top image shows the normal proton aurora formation mechanism first discovered in 2018. White lines show that solar wind protons traveling away from the Sun are normally swept around the planet by the Mars magnetosphere, and don't directly interact with the atmosphere. When proton aurora occur, a small fraction of the solar wind collides with Mars hydrogen in the extended corona of the planet (shown in blue), and charge exchanges into neutral H atoms. These newly created H atoms are still travelling at the same speed, and are no longer sensitive to the magnetospheric forces that redirect protons around the planet. Instead, the energetic H atoms slam directly into the upper atmosphere of Mars and collide multiple times with the neutral atmosphere, resulting in auroral emission by the incident H atoms (purple). Because the solar wind and Mars corona are uniform across the planet, the aurora occurs everywhere on the planet's day side with a uniform brightness. Bottom image shows the newly discovered formation mechanism for patchy proton aurora. Green lines in the top image show that under normal conditions the solar wind magnetic field drapes nicely around the planet. By contrast, patchy proton aurora form during unusual circumstances when the solar wind magnetic field is aligned with the proton flow. Under such conditions the typical draped magnetic field configuration is replaced by a highly variable patchwork of plasma structures, and the solar wind is able to directly impact the planet's upper atmosphere in specific locations that depend on the structure of the turbulence. When incoming solar wind protons collide with the neutral atmosphere, they can be neutralized and emit aurora in localized patches. During such times patchy proton aurora forms a map of the locations where solar wind plasma is directly impacting the planet. Image Credit: Emirates Mars Mission/UAE Space Agency NASA’s MAVEN (Mars Atmosphere and Volatile Evolution) mission and the United Arab Emirates’ Emirates Mars Mission (EMM) have released joint observations of dynamic proton aurora events at Mars. Remote auroral observations by EMM paired with in-situ plasma observations made by MAVEN open new avenues for understanding the Martian atmosphere. This collaboration was made possible by recent data-sharing between the two missions and highlights the value of multi-point observations in space.Learn more about this discovery by MAVEN and EMM. For More InformationSee [NASA.gov](https://www.nasa.gov/feature/goddard/2022/maven-emm-proton-aurora) Related pages

Ultraviolet images from NASA's Mars Atmosphere and Volatile Evolution mission, MAVEN, were used to make this movie of rapid cloud formation on Mars. Watch this video on the NASA.gov Video YouTube channel. 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. For More InformationSee [NASA.gov](http://www.nasa.gov/press-release/goddard/2016/maven-uv-mars) Related pages

Scientists have long suspected the solar wind of stripping the Martian upper atmosphere into space, turning Mars from a blue world to a red one. Now, NASA's MAVEN orbiter is observing this process in action, providing significant data on solar wind erosion at Mars.Watch this video on the NASA Goddard YouTube channel.Complete transcript available.This video is also available on our YouTube channel. The solar wind accelerates ions from the Mars upper atmosphere into space.Watch this video on the NASAexplorer YouTube channel. Movie without music and titles. Available for download in up to 4k resolution. The solar wind interacts with the Mars upper atmosphere, but is deflected past Earth by a global magnetic field (artist's concept).Credit: NASA/GSFC A solar storm approaches Mars (artist's concept). The Red Planet is thought to have lost much of its atmosphere to such extreme space weather.Credit: NASA/GSFC Artist’s rendition of a solar storm hitting Mars and stripping ions from the upper atmosphere.Credit: NASA/GSFC During a solar storm (right), Mars experiences a dramatic increase in atmosphere loss, compared with normal solar wind conditions (left). Artist's concept.Credit: NASA/GSFC Print resolution still of MAVEN observed O+ ion flux chart (with Mars) Print resolution still of MAVEN observed O+ ion flux chart (without Mars) Solar wind (moving from right to left) hitting Mars' induced magnetic field (in blue) Solar wind (moving from left to right) hitting Mars' induced magnetic field (in blue) Today, Mars is a global desert with an atmosphere far too thin to support bodies of flowing water, but evidence shows that Mars was considerably wetter in the ancient past. Scientists think that climate change on Mars was caused by the loss of an early, thick atmosphere, and NASA’s MAVEN mission is investigating whether it was driven into space.One of the prime suspects is the solar wind, a stream of electrically charged particles continuously blowing outward from the Sun. Unlike Earth, Mars lacks a global magnetic field to deflect the incoming solar wind. Instead, charged particles from the Sun crash into the Mars upper atmosphere, and can accelerate Martian ions into space. Now, MAVEN has observed this process in action – by measuring the velocity of ions escaping from Mars.The movies on this page compare simulations of ion escape with MAVEN’s observations of oxygen ion flux. The results closely fit the expected pattern, with the most energetic ions (in red) accelerated in a plume above Mars, while the majority of escaping ions (green) are lost along the “tail” region in the wake of the solar wind. MAVEN’s observations confirm that the solar wind is a significant contributor to atmosphere loss on Mars, and they bring scientists closer to solving the mystery of the ancient Martian climate. Read the full press release about this finding.Watch the November 2015 MAVEN Science Update. For More InformationSee [NASA.gov](http://www.nasa.gov/mission_pages/maven/main/index.html) Related pages

Simulation of the solar wind at Mars compared with MAVEN observations, showing the predicted bow shock. Available for download in up to 4k resolution. Print resolution still of MAVEN observed average solar wind flow (with Mars) Print resolution still of MAVEN observed average solar wind flow (without Mars) Today, Mars is a global desert with an atmosphere far too thin to support bodies of flowing water, but evidence shows that Mars was considerably wetter in the ancient past. Scientists think that climate change on Mars was caused by the loss of an early, thick atmosphere, and NASA's MAVEN mission is investigating what could have driven its escape.One of the prime suspects is the solar wind, a stream of electrically charged particles continuously blowing outward from the Sun. Unlike Earth, Mars lacks a global magnetic field to deflect the incoming solar wind. Instead, charged particles from the Sun slam into the Mars upper atmosphere, piling up in a bow shock ahead of the planet. The inner boundary of this bow shock reaches the Mars ionosphere, and can accelerate ions to escape velocities. During solar storms, the bow shock pushes even deeper into the atmosphere and is accompanied by increased rates of ion escape.The visualization on this page compares a simulation of the solar wind at Mars with data from the MAVEN spacecraft. MAVEN's observations confirm the existence of a bow shock, with a density and shape matching the predicted pattern. Thanks to MAVEN, scientists can now observe the solar wind at Mars during both normal and extreme conditions, allowing them to study the Sun's ongoing role in the evolution of the Martian climate.Read the full press release about this finding.Watch an excerpt of the MAVEN Mission Briefing. For More InformationSee [NASA.gov](http://www.nasa.gov/mission_pages/maven/main/index.html) Related pages

Principal Investigator Bruce Jakosky talks about MAVEN’s science observations at Mars.Watch this video on the NASAexplorer YouTube channel.For complete transcript, click here. MAVEN gazes at the setting stars during one of its stellar occultation campaigns. MAVEN's near-polar orbit gives it latitudinal coverage of the Martian atmosphere, while the planet's daily rotation provides longitudinal coverage. During its periodic "deep dip" campaigns, MAVEN lowers its closest approach to only 125 km above Mars, dipping into the upper atmosphere to measure it in situ. When water molecules are split apart in the Martian atmosphere, the resulting hydrogen atoms escape more easily from the planet than the heavier oxygen atoms. Before MAVEN entered its final science-mapping orbit, it observed carbon, oxygen, and hydrogen at varying altitudes above Mars. The heavier carbon and oxygen atoms cling tightly to Mars, while hydrogen atoms extend far above the planet. High above the thin Martian skies, NASA’s MAVEN spacecraft is carrying out a mission: determine how Mars lost its early atmosphere, and with it, its water. While previous Mars orbiters have peered down at the planet’s surface, MAVEN is spending part of its time gazing at the stars, looking for subtle changes in their color as they dip through the limb of Mars and set below the horizon. Such stellar occultations reveal what the atmosphere is made of, and how its composition varies with altitude. MAVEN’s observations are providing the most detailed picture of the Mars upper atmosphere to date, helping scientists understand how Mars turned from a warm and wet planet in its youth, into the forbidding desert that we see today. For More InformationSee [NASA.gov](http://www.nasa.gov/mission_pages/maven/main/index.html) Related pages