(Animation) Proton Aurora at Mars (IMAGE) NASA/Goddard Space Flight Center Caption This animation shows a proton aurora at Mars. First, a solar wind proton approaches Mars at high speed and encounters a cloud of hydrogen surrounding the planet. The proton steals an electron from a Martian hydrogen atom, thereby becoming a neutral atom. The atom passes through the bowshock, a magnetic obstacle surrounding Mars, because neutral particles are not affected by magnetic fields. Finally, the hydrogen atom enters Mars' atmosphere and collides with gas molecules, causing the atom to emit ultraviolet light. View animated GIF: https://cms.nasa.gov/sites/default/files/thumbnails/image/marsprotonauroramovie1080v4.gif Credit NASA/MAVEN/Goddard Space Flight Center/Dan Gallagher Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.