Mars Orbiter Mission photo of the far side of Deimos
Like most solar system moons, Deimos always keeps the same hemisphere facing Mars. It's rare for spacecraft to view the hemisphere that faces away from Mars, but Mars Orbiter Mission's long, elliptical orbit permits it to do that. This image is a composite of four different exposures, stacked and enlarged 400%.
Here are the four individual images used to create the composite:
Four views of the anti-Mars side of Deimos by Mars Orbiter Mission
Mars Orbiter Mission captured these four images of Deimos about 12 seconds apart at 13:06 UT on October 14, 2014. The images have a resolution of about 300 meters per pixel; Deimos is roughly 13 kilometers wide.