This false-color image of Phobos, the larger and inner of the two natural satellites of Mars, was taken by the Imaging Ultraviolet Spectrograph instrument aboard NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft in ultraviolet (UV) light.
Mars’ moon Phobos as observed by NASA’s MAVEN spacecraft. Image credit: NASA / CU /LASP.
Orange shows mid-UV sunlight reflected from the surface of Phobos, exposing the moon’s irregular shape and many craters.
Blue shows far-UV light detected at 121.6 nm, which is scattered off of hydrogen gas in the extended upper atmosphere of the Red Planet.
Phobos, observed here at a range of 186 miles (300 km), blocks this light, eclipsing the UV sky.
This and several other images will allow members of the MAVEN science team to better assess the composition of Phobos.
Comparing MAVEN’s images and spectra of the surface of the tiny moon (16.7 x 13.7 x 11.2 miles in diameter, or 27 x 22 x 18 km) to similar data from asteroids and meteorites will help the scientists understand the moon’s origin – whether it is a captured asteroid or was formed in orbit around Mars.
The MAVEN data will also help the researchers look for organic molecules on the surface.
Evidence for such molecules has been reported by previous measurements from the UV spectrograph on ESA’s Mars Express spacecraft.
