Editors’ Highlights are summaries of recent papers by AGU’s journal editors.
Source: Journal of Geophysical Research: Planets
Water flowed on ancient Mars, but the timing, duration, effects, and exact nature of liquid water systems at or near the surface are still debated by planetary scientists. One setting where water could have been prevalent on early Mars is hydrothermal circulation—that is, the heat-driven circulation of warm water within the crust—under craters.
Mittelholz et al. [2025] test the presence and duration of hydrothermal systems under impact craters on early Mars by considering the effects that those systems would have on geophysical parameters of the Martian crust that we can observe today. In particular, the authors focus on the concepts that hydrothermal circulation would efficiently cool the local crust, hindering the deformation of craters that occurs when rocks are warm, and would alter the magnetization of the crust through chemical processes associated with the extensive water-rock interaction triggered by hydrothermal systems. The authors use sophisticated data analyses and numerical models to show that the orbital gravity and magnetic data collected by Mars-orbiting spacecraft are consistent with these effects of hydrothermal circulation in several regions on Mars.
The study finds that the water-rock interactions associated with hydrothermal circulation were not only present on early Mars, but long-lasting. Additionally, the study demonstrates how an interdisciplinary approach—tying together geophysics and geochemistry, gravity and magnetism, crust and core—can be used to address big picture questions about planetary habitability. The authors argue that a dedicated gravity mission in Martian orbit or regional magnetic studies conducted near the surface could further test these ideas.
Citation: Mittelholz, A., Moorkamp, M., Broquet, A., & Ojha, L. (2025). Gravity and magnetic field signatures in hydrothermally affected regions on Mars. Journal of Geophysical Research: Planets, 130, e2024JE008832. https://doi.org/10.1029/2024JE008832
—Michael M. Sori, Associate Editor, JGR: Planets
