High-pressure clathrate hydrates in large ocean worlds – CAGES

Icy satellites of Jupiter and Saturn are the only extra-terrestrial planetary bodies where the presence of liquid water has been discovered in a form of subsurface oceans. Subsurface oceans are nowadays the most appealing astrobiological targets and became the focus of diverse interdisciplinary research as well as of upcoming space missions. While a variety of volatile compounds (CO2, CH4, N2, NH3, CH3OH, etc) are expected to be present in significant amount in the oceans of icy satellites of Saturn and Jupiter, they should be stable in the form of gas clathrate hydrates at relevant high-pressure and from low- to temperate-temperature conditions. Clathrate formation and destabilization govern the volatile reservoir and chemical exchange in the interior, and have a major impact on the ocean composition, evolution and astrobiological potential. Despite being the main reservoir of volatiles in large ocean worlds, our knowledge on stability and properties of chemically relevant clathrate hydrates at relevant thermodynamic conditions is very limited. To address the mineralogy, evolution and astrobiological potential of extra-terrestrial oceans and to provide data critical for preparing the future space missions, the current proposal aims exploring multicomponent clathrate hydrates in a wide range of pressures, temperatures and compositions by using in situ single-crystal X-Ray diffraction and Raman spectroscopy at high pressures and low to ambient temperatures.