Exploring the Habitability of Icy Worlds: The Europa Jupiter System Mission
Robert T. Pappalardo (JPL / Caltech)
The search for life in the outer solar system focuses on active, ocean-bearing moons. While several icy satellites may contain oceans within, Europa's ocean seems astrobiologically most promising, with a relatively thin ice shell above, and direct contact with a rocky mantle below. This differs from the more common ocean sandwich within large moons as exemplified by Ganymede, with ice I above, and higher density ice polymorphs below. The Europa Jupiter System Mission (EJSM) is a planned combined NASA-ESA endeavor to explore Europa, Ganymede, and the Jupiter system. The mission concept has as its overall theme: The emergence of habitable worlds around gas giants. It consists of a NASA-led Jupiter Europa Orbiter (JEO) and an ESA-led Jupiter Ganymede Orbiter (JGO), which would execute a choreographed exploration of the Jupiter System for ~2.5 years before settling into orbit around Europa and Ganymede, respectively, for 9-12 months to investigate the potential habitability of these worlds. JEO would characterize Europa's ocean and deeper interior, ice shell and any subsurface water, surface composition and chemistry, geology including potential future landing sites, and interactions with the external environment including the tenuous atmosphere, and JEO will understand Europa in the context of the Jovian system. JGO's analogous detailed exploration of Ganymede would provide unprecedented comparative planetology of these active, ocean-bearing worlds. EJSM would shed new light on the potential habitability of icy worlds in our solar system and beyond.