In situ analysis of Europa ices by short-range melting probes

A key aspect for understanding the astrobiological potential of planets and moons in the Solar system is the analysis of material embedded in or underneath icy layers on the surface. In particular in case of the icy crust of Jupiters moon Europa such investigation would be of greatest interest. For a Europa lander to be launched in the 2020–2030 timeframe, we propose to use a simplified instrumented melting probe which is able to access and sample depths of a few meters without the necessity of heavy and complicated drilling equipment. While melting probes have successfully been used for terrestrial applications, e.g. in Antarctic ice, their behavior in vacuum and at very low temperatures is different and theory needs confirmation by tests. In an earlier work, the planetary simulation chamber at DLR in Cologne has been used to perform a series of melting tests in cold (LN2-cooled) water ice samples. The feasibility of the method could be demonstrated and the energy demand for a space mission was estimated. A simplified melting probe to access the uppermost meters of Europa’s crust appears to be feasible yet very demanding in terms of energy. The melting probe needs to be equipped with a suite of scientific instruments that are capable of determining the chemical and isotopic composition of the embedded or dissolved materials and which are indicative of organic material. An overview of potential instrumentation is given.