TAPHONOMY OF JUPITER´S ICY MOON EUROPA

Jupiter’s moon Europa may have an ocean below its icy crust, energy sources (hydrothermal vents, tidal motions) and radiogenic nutrients. Europa is thus a primary target for life in the Solar System. Paleontologic search strategies are based on inferred habitats and their incorporation and exposure in the surface ice where orbiting or surface instruments may discover them. Four habitats are possible in the ice (pores and cracks in the top and bottom ice, fissures, and surficial cryptic environments), four in the water column below the ice (near ice; near the seafloor; the entire water column; and different water layers), and four on the seafloor (soft and firm substrata, hydrothermal vents, and submarine volcanoes). These might be incorporated into the crust through various mechanisms (anchor ice, ice ploughing, density flotation, cryovolcanism, and tidal and current action).

Extant or extinct habitats may be exposed in outcrops or slumps in tectonic features, including ridges and troughs formed by tidal flexing, chaotic terrains with displaced ice blocks kms across embedded in a matrix of disturbed ice, bands of newer ice, cryovolcanoes, domes and pits, and fault scarps. Impact craters pierce the crust, exposing older ice in crater walls, central peaks, overturned ice, and ejecta. Opportune sites for studying habitats and their contained life can be characterized by a high resolution orbiting telescopic instrument (MIDAS=Multiple Instrument Distributed Aperture Sensor) that can resolve geologic and astropaleobiologic targets with 2 cm/pixel spatial resolution and nanometer hyperspectral sensing, and actively probe the surface with lasers. Once targets are selected, surface instruments may be landed for additional analyses by microscopic and chemical sensors.