Stripping the Martian Atmosphere

Mars' magnetic tail is shaped and twisted by the solar wind. The solar wind interacts with the Mars upper atmosphere, but is deflected past Earth by a global magnetic field (artist's concept). The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun's atmosphere at a speed of about 1 million mph. Solar magnetic field lines (yellow) interact with Martian surface magnetic fields (blue), and result in reconnected magnetic fields (red). MAVEN has been studying Mars since 2014, investigating the Red planet's magnetosphere and atmosphere. For More InformationSee [NASA.gov](https://www.nasa.gov/press-release/goddard/2017/mars-twisted-tail) 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