They could be from Mars itself
They could also be the result of debris thrown up from one of the major
impacts that hit Mars, such as the one that made the Hellas basin.
Space/Science » in reply to re: That Phobos and Deimos are captured C-type asteroids is one of several theories...but it would seem not to explain their low density though.
They could also be the result of debris thrown up from one of the major
impacts that hit Mars, such as the one that made the Hellas basin.