IIRD 2024 – Enceladus Plumes

Plumes coming from Enceladus via the Cassini spacecraft flyby (NASA/JPL/SSI).

The Saturnian moon Enceladus is a particularly promising target in the search for extraterrestrial life detection, given its large liquid ocean. While direct sample retrieval from this ocean is made difficult by the kilometers-thick ice shell surrounding it, Enceladus is host to prominent geysers that deliver the contents of this ocean to the surface (featured in this image taken during a Cassini flyby). This is a boon to life detection missions, but any life or biosignatures present in this ejecta would be exposed to the stressors of aerosolization, average surface temperatures nearing -200C, prolonged exposure to near-vacuum conditions, and UV and charged particle irradiation. While these factors have been tested independently for their impacts on microorganisms, there has yet to be a study that examines these conditions in tandem. Notably – recent studies examining the effects of aerosolization into vacuum typically do not include the cryogenic temperatures expected – temperatures which can be expected to enhance microbial survival against adverse conditions.

This pilot project, funded internally through the Applied Physics Laboratory’s Interdepartmental Interdisciplinary Research & Development (IIRD) Program, will seek to build an inexpensive Enceladus geyser simulator capable of subjecting a range of cold-adapted microorganisms to many of the simultaneous conditions expected here, crucially including low or cryogenic temperatures. Our interdisciplinary team includes PI Karen Junge (UW APL-PSC), Co-I Erin Firth (UW APL-PSC), Co-I Anuscheh Nawaz (UW APL-OE), and Co-I Kaizer Contreras (UW APL-CIMU).