Phobos and Deimos: Captured Asteroids or Cut From Ancient Mars?

Illustration of Mars with its two moons, Phobos and Deimos. (NASA/JPL-Caltech/Malin Space Science Systems/Texas A&M Univ.) The global success rate for sending missions to land on the moons of Mars has hardly been impressive -- coming in at zero out of three attempts.  They were all led by the Russian (or former Soviet) space agencies, …