Experimental investigation of impact cratering on Phobos

JAXAs Martian Moon eXploration (MMX) sample return mission aims to solve the long-debated origin of Martian moons Phobos and Deimos 1.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.We will present the preliminary results of our laboratory investigation of impact experiments using Phobos simulant materials at the Impact Lab of the University of Kent.Acknowledgements: We acknowledge CNES and ESA-OSIP funding for initiating this work.References:1. Usui et al. Space Science Reviews 216, Issue 4, article id.49 (2020).2. Levison et al. Nature 460, Issue 7253, pp. 364-366 (2009).3. Vokrouhlicky, Bottke, Nesvorny. The Astronomical Journal 152, Issue 2, article id. 39, 20 pp. (2016).