This obviously false color animation of Mars shows how its atmosphere glows and pulsates in ultraviolet light every night. It was assembled from months of data taken by the MAVEN spacecraft orbiting Mars. The nightglows occur three times during each rotation of the planet about 70 km above the surface. All three occur at sunset (which is on the left limb of the planet in this view). The pulsations are believed to be caused by downward winds creating nitric oxide in the atmosphere which glows in the UV spectrum. The fact that the three glows occur in data averaged over several months indicates that they are a nightly occurrence.
Video Credit: NASA
This is the Martian moon Phobos as observed by the MAVEN spacecraft’s Imaging Ultraviolet Spectrograph. Orange shows mid-ultraviolet (MUV) sunlight reflected from the surface of Phobos. Blue shows far ultraviolet light which is scattered off of hydrogen gas in the extended upper atmosphere of Mars. Phobos blocks the background far UV light, eclipsing the ultraviolet sky. Comparing MAVEN’s images and spectra of the surface of Phobos to similar data from asteroids and meteorites may provide clues to the moon’s origin–whether it is a captured asteroid or was formed in orbit around Mars. The MAVEN data will also help scientists look for organic molecules on the surface of Phobos. Evidence for such molecules has been reported by previous measurements from the ultraviolet spectrograph on the Mars Express spacecraft.