Martian moon samples will have bits of Mars
Brown University said:
The study helps to confirm the idea that the surface of Phobos contains tons of dust, soil, and rock blown off the Martian surface by large projectile impacts. Phobos’ orbital path plows through occasional plumes of Martian debris, meaning the tiny moon has been gathering Martian castoffs for millions of years. That means a sample-return mission planned by the Russian space agency could sample two celestial bodies for the price of one.