MICROorganisms under simulated ICY moon environments: supporting solar system exploration (MICRO ICY project)

Abstract

The exploration of icy moons in the solar system marks a new chapter in the search for extraterrestrial life, with next-generation missions targeting these promising environments. Cassini's flybys of Enceladus revealed a global subsurface ocean containing organic compounds and biologically available nitrogen, suggesting potential conditions for life as we know it. Other moons with subsurface oceans, such as Europa, Titan, Ganymede, and Callisto, are now considered more common in the cosmos than once believed. Enceladus thus provides a critical platform for advancing astrobiological research and technology.

Given the challenges of space exploration, Earth-based (both in-situ and laboratory) experiments are crucial for interpreting remote data and understanding icy moon processes. Terrestrial hydrothermal sites, similar to those expected on Enceladus, shed light on the origins and preservation of life, expanding our knowledge of the habitability concept. Microbial extremophiles thriving in these environments allow to refine life's boundaries and support the search for life elsewhere.

In this context, the MICROICY project aims to: (i) study microbial communities in the Strýtan alkaline shallow-water hydrothermal vents in Iceland, analogues to Enceladus' hydrothermal vents; (ii) assess the adaptation mechanisms of extremophiles under Enceladus-like conditions; and (iii) detect gas biosignatures of microbial activity using a mass spectrometry detector. These findings will support the use of gas biosignatures in next-generation astrobiology missions, advancing the exploration of Enceladus and other icy moons.