The Structural, Thermal, and Magnetic History of Europa's Rock-Metal Interior with Implications for Seafloor Geochemistry

Project: Research project

Project Details

Description

While the advent of NASA Galileo inspired a wave of ground-breaking research on Europa, much remains unknown about the formation and evolution of Europas deep interior. This lack of understanding challenges geophysical and geochemical investigations on the persistence of Europas habitability since deep interior processes play a role in heat and chemical energy deposited into the subsurface ocean. Existing studies typically assume that Europa possessed its metallic core immediately after accretion. However, unlike the terrestrial planets, Europa is too small to differentiate its metal-silicate interior and dehydrate its silicates solely by heat derived by gravitational energy during accretion. This is problematic since core formation and silicate dehydration act as potentially important heat sinks in Europas thermal evolution. Neglecting these processes will result in warmer thermal histories.

We will address four key questions: 1) When did Europa form its metallic core? 2) What are the prospects of an ancient core-hosted dynamo at Europa? 3) What are the prospects of past and present volcanic activity? and 4) What is the composition of aqueous fluids produced by serpentinization over time?

We propose investigating the role of deep interior processes on the history of Europas ocean habitability in two tasks:

1) Model the internal differentiation and evolution of Europa. We will build a one-dimensional (radial) model of Europas structural, thermal, and magnetic evolution while incorporating key geologic processes that act as heat sinks: core formation and evolution, silicate hydration and dehydration, and if applicable, solid-state mantle convection and seafloor volcanism. (Addresses questions 1-3)

2) Model the composition of aqueous fluids produced by rock-water reactions. We use EQ3/6, an open-sourced software package for chemical kinetics and thermodynamics, to do reaction path calculations. Using the temperature and pressure conditions set by Task 1, we determine mineral assemblages and extent of redox reactions (e.g. H2 and O2 production) over time. (Addresses question 4)

Our proposed work is relevant to the Planetary Science Division science goals. By modeling Europas evolution, we Explore and observe the objects in the Solar System to understand how they formed and evolve. We also assess the potential for life elsewhere by modeling processes that influence the heat and chemical energy available in the subsurface ocean. If our work confirms the habitable potential of Europa, we may inspire a new wave of research on icy moons with similar characteristics to Europa, thus we "improve our understanding of the origin, evolution, distribution, and future of life in the Universe". Our work is timely given the anticipated launch of Europa Clipper in the mid-2020s. The geophysical and geochemical evolution of Europa has strong implications for formation time, metallic core size, and potential volcanism at the seafloor which can be validated against gravity measurements.
StatusActive
Effective start/end date9/1/218/31/24

Funding

  • NASA: Headquarters: $135,000.00

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