NEW GLOBAL GEOLOGIC MAP OF EUROPA

Jupiter’s icy moon Europa is one of the most geologically complex satellites in our solar system. Its relatively young surface is covered by numerous fractures, ridges, bands, chaos, and other structures which commonly overlap with one another. The complex surface, along with the variable lighting conditions and image resolutions from the Galileo solid state imager (SSI) data set, make the creation of a geologic map challenging. However, with the upcoming Europa Clipper mission, a global geologic map is necessary to help facilitate mission planning and scientific investigations by providing a uniform map to reference. Here we present our new geologic map of Europa and describe the stratigraphic relationships, individual features, and identified units: chaos, bands, ridged plains, and craters. Individual mapped features are those that are greater than ~5 km in width and continue in length for 100s km, e.g. large cycloids and bands. Chaos, the youngest unit, is identified and subdivided into a low albedo, high albedo, mottled, and knobby units. Low albedo chaos appears to be disrupted terrain with a relatively uniform low albedo while the high albedo chaos is similarly disrupted but has a much higher uniform albedo. Mottled chaos appears as disrupted, patchy terrain but with a variable albedo, while the knobby chaos unit is a disrupted terrain with a rough and blocky texture and is commonly found at high latitudes. Bands are generally linear to curvilinear zones with sharp boundaries where there is an abrupt albedo change. Individual bands appear to cross-cut most other structures which suggests this unit is relatively young. Ridged plains consist of numerous subparallel to cross-cutting ridges and troughs and is the most wide-spread unit. This unit is commonly disrupted by other units suggesting it is older than the other terrains. The craters unit encompasses both the central crater and any visible surrounding ejecta deposits.