Europa, one of Jupiter’s many moons, may support life because its icy surface likely covers a deep, salty ocean. Europa’s ocean is also in direct contact with mantle rocks, and interactions between rock, water, and ice can provide energy to support life.

DG Lemasquerier and colleagues examined how warming Europa’s mantle might stimulate ocean circulation beneath the icy crust. Researchers modeled Europa’s ocean to better understand how warming from the moon’s depths might affect the thickness of its icy surface. The study was published in the journal AGU Developments.

Mantle heat is one of the driving forces behind Europa’s ocean circulation, and this warming occurs in two ways. Radiogenic heating results from the decay of radioactive materials in the mantle, and tidal heating results from the deformation Europa undergoes as it orbits Jupiter and experiences its strong gravitational pull. Tidal heating is uneven; It is higher at the poles of Europe and lower at opposite points of the Moon facing Jupiter.

Using simplified, idealized simulations that ignore salinity and feedback between ocean and ice, the researchers investigated how heat might be transferred from Europa’s seafloor to the ocean and ice sheet. They found that if tidal heating dominates the mantle, fluctuations in latitudinal heat flux from the bottom will carry up across the ocean and remain essentially unchanged at the ice-ocean boundary, affecting ice thickness and keeping it thinnest at the poles.

However, if the dominant type of heating in the mantle is radiogenic heating, then it will have relatively little impact on ocean ice thickness. The Europa Clipper mission in 2024 could help confirm these model findings and provide new insights into the relationship between Europa’s mantle warming, ocean circulation, and the thickness of its ice shell.