Photo of the surface of Jupiter’s icy moon, Europa.
The surface of Jupiter’s icy moon Europa in a color image taken by NASA's Galileo spacecraft in the late 1990s. The characteristic features of the moon’s surface will allow future missions to test the rate of ice shell rotation compared to the predictions made by Ashkenazy et al. [2023]. Credit: NASA/JPL-Caltech/SETI Institute
Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: AGU Advances

The deep oceans of icy moons, like Europa, have been suggested as one place that could host extraterrestrial life. Currently, Europa always displays the same side towards Jupiter, just as we always see the same side of our moon. However, there are indications that Europa’s icy shell slowly drifts such that, over time, different parts face Jupiter.

Ashkenazy et al. [2023] propose that this effect could be driven by stresses from deep ocean currents acting on the ice shell. They developed a physical/mathematical model for linking ice shell movements to ocean currents, including deformation within the ice itself. The model predicts an ice shell that could be spinning slower than the synchronous angular rate that would keep the same point facing Jupiter. Forthcoming spacecraft missions will provide improved observations of Europa’s ice shell drift and can be used to constrain key parameters, such as the ice thickness and viscosity of Europa’s icy shell.

Citation: Ashkenazy, Y., Tziperman, E., & Nimmo, F. (2023). Non-synchronous rotation on Europa driven by ocean currents. AGU Advances, 4, e2022AV000849.

—Susan Trumbore, Editor in Chief, AGU Advances

Text © 2023. The authors. CC BY-NC-ND 3.0
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