Experimental investigation of impact cratering on Phobos

JAXA’s Martian Moon eXploration (MMX) sample return mission aims to solve the long-debated origin of Martian moons Phobos and Deimos.

This will be the first attempt to sample an object that either formed in the outer solar system and implanted [2,3] into the terrestrial planet region by a major dynamical process (the first origin scenario); or formed from a large impact and subsequently accumulated material from two, very possibly compositionally different, bodies, i.e. Mars and the impactor (the second scenario). In either scenario, impact processes by asteroids, meteoroids as well as Martian eject have altered the surfaces of the Martian moons and require investigation to study several aspects such as the crater formation and exposure of fresh sub-surface material, the comminution of surface boulders and regolith production, and the delivery of exogenous materials. To provide a frame for the MMX data interpretation, a laboratory experimental campaign is proposed simulating the impact processes on Phobos.