SPS Seminar - A metamorphic origin for Europa’s ocean

When:  Thursday 1^st July at 14.00

Where:  Microsoft Teams - Online

Speaker:  Mohit Melwani Daswani (Jet Propulsion Laboratory – California Institute of Technology)

Hosted by: Alexandra Barrett

Abstract:

Europa likely contains an iron-rich metal core. For it to have formed, temperatures within Europa reached ≳1250 K. At that temperature, accreted chondritic minerals—e.g., carbonates and phyllosilicates—would partially devolatilize. We computed the amounts and compositions of exsolved volatiles, and found that those volatiles released from the interior would have carried solutes, redox-sensitive species, and could have generated a carbonic ocean in excess of Europa’s present day hydrosphere, and potentially an early CO2 atmosphere. Contrasting with prior work, CO2 could be the most abundant solute in the ocean – which may be testable by NASA’s Europa Clipper mission. The thermal evolution of ocean worlds appears to be understudied when considering the origin and composition of their oceans. I will address how we are carrying out similar efforts to constrain the composition of Ceres’ early ocean, in a manner that explains Ceres’ low-density mantle and crust as observed NASA’s Dawn spacecraft.

Bio:

I am a geochemist and planetary scientist studying the composition of subsurface oceans within icy moons, including Europa, Enceladus and Titan. I received my Joint M.Sc. in Geoinformation Science and Earth Observation at the Universities of Southampton, Lund, Warsaw and Twente, where I focused on remote sensing and mineralogical mapping of the surface of Mars. During my Ph.D. at the Open University (UK), I worked on a number of martian meteorites, including (the somewhat infamous) Allan Hills (ALH) 84001. In 2015, I became a Postdoc at the University of Chicago, where I characterized the composition of the ancient salty lakes of Mars and the hydrological and climatological conditions that led to their formation. I moved to JPL in 2018, where I now perform simulations of the interaction between rocks and fluids inside high-pressure vessels in the laboratory and use thermodynamic and numerical models to study the physical and chemical conditions of ocean worlds."