Investigating Europa's Habitability ahead of Europa Clipper/Juice

Europa is one of Jupiter's largest moons, it has an active icy shell crust over a global liquid water ocean. The ocean is likely sustained through tidal heating due to its eccentric orbit around Jupiter. If this structural understanding of Europa is correct, then Europa's subsurface ocean is one of the leading places in our solar system believed to be capable of hosting non-Earth-based life.

To test Europa's habitability two upcoming missions will observe Europa in unprecedented detail and search for signatures of habitability: ESA's Jupiter Icy Moons Explorer (Juice, arriving 2031) and NASA's Europa Clipper (EC, arriving 2030). This work aims to better understand Europa's potential habitability using existing data sets, to inform on Juice and EC's observing strategy.

The study of habitability is really a study to reveal whether a target has the environmental conditions to support life. For example, this includes the study of a target's temperatures, pH, salinity, pressure and whether it has a solvent (e.g. water).For example, EC will assess Europa's habitability by using its instrumentation to: (1) characterize Europa's ice shell, ocean, and any subsurface water, including heterogeneity, ocean properties, and the nature of surface-ice-ocean exchange; (2) understand Europa's composition and chemistry; and (3) understand the formation of surface features and characterize localities of high science interest.

This project will use existing data sets and models to better characterize the surface temperature and properties of Europa's ice shell, with a view to informing on Europa's heat flow and thus its habitability. Through Dr. Howett's involvement in Europa Clipper (and through that Juice) the results will be used by the missions to ensure any regions of interest identified by this work are more thoroughly investigated.

Aims and Objectives

Aim: To better understand Europa's surface and sub-surface ice, to inform on its heat flow and thus Europa's habitability. Objectives: Use existing Galileo PPR data to map Europa's surface temperatures.

Compare these maps to those of geology, albedo, surface colour, radiolytic bombardment and composition to determine any correlations. Investigate any potential correlations, including searching for active regions, including plume sources. As appropriate combine the results to models of ice-convection to determine how observed heat flows could be produced.

As appropriate use the surface temperature maps to constrain surface properties (albedo and thermal inertia).

Alignment with STFC's goals: This project, to better understand Europa, clearly falls within the remit of STFC's science goal to better understand our universe. Specifically, this falls inside the remit of STFC's Challenge Question "How do stars and planetary systems develop and how do they support the existence of life?"

Collaborators: Currently this work is being supported only by Dr. Carly Howett. However, it is likely that other collaborators are brought in throughout the project including Dr. John Spencer and Dr. Julie Rathbun (PPR data analysis). As Sarah develops this work, we expect her to becomes increasingly involved in the Habitability Working Group of the Europa Clipper Mission Team.