Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Planets
The Voyager spacecraft first observed central dome craters on the icy moons Ganymede and Callisto in 1979. These craters were eye-catching because they were unique to these icy worlds and likely to reveal important information about the icy moons’ composition and interior evolution.
Central domes are much broader, smoother, and more rounded than traditional central peak craters (such as those occurring on the Moon or other rocky bodies). They also only occur for craters larger than about 60 kilometers in size and are generally larger than another class of craters called central pit craters.
These clues led Caussi et al. [2024] to numerically model the evolution of central pit craters into central dome craters. Residual heat from the impact itself concentrates below a central pit, leading that ice to be warmer and more mobile than the surrounding ice. That central mobile ice can more easily flow and rise up in response to the stress field created by the crater topography. The modeling indicates that central domes can form relatively quickly (within 10 million years) when there is enough overall heat flow from Ganymede’s or Callisto’s interior.
Citation: Caussi, M. L., Dombard, A. J., Korycansky, D. G., White, O. L., Moore, J. M., & Schenk, P. M. (2024). Dome craters on Ganymede and Callisto may form by topographic relaxation of pit craters aided by remnant impact heat. Journal of Geophysical Research: Planets, 129, e2023JE008258. https://doi.org/10.1029/2023JE008258
—Kelsi Singer, Associate Editor, JGR: Planets
Text © 2024. The authors. CC BY-NC-ND 3.0Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.
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