Impact cratering into water-covered targets on Mars

Mars is a cold dry planet, yet there is ample evidence for fluvial activity on its past surface, including sediments suggestive of shallow lakes, which paints a different picture for the Martian past climate. Mars is also heavily cratered, and some of those craters may have resulted from impact cratering into water-covered targets. Distinguishing between water-overed and dry surface at the time of the impact is the topic of this project. We approach this problem from the theoretical point of view and use a shock physics code iSALE capable of simulating different materials with various strength and damage models. This hydrocode is widely used in impact physics and has been extensively tested against laboratory experiments. We realise several impact scenarios with varied rheology, as well as sizes of projectiles and impact angles, in particular water-covered (simulated paleolake), water ice-rich and dry targets. We discuss the theoretical effects of the presence of surface water on the morphology and dynamics of impact sites (both craters and ejecta). Distinguishing between these scenarios can aid the interpretation of remote sensing observations, and open a possibility of using a new independent observable to study the past climate of Mars.