New analysis of high-resolution images shows that Martian gullies can change over time, resembling water-carved gullies seen on Earth. Because Mars is cold and its atmosphere is too thin to support stable liquid water on the surface, researchers say the activity is unlikely to be caused by water runoff.
A preprint paper by Apolline Leclef and colleagues at the Institut d’Astrophysique Spatiale (Université Paris-Saclay) examines an alternative mechanism. The study proposes that seasonal CO2 frost on Mars can sublimate and transition into a fluid-like form that flows and erodes the landscape, carving or reshaping gullies. This explanation aims to account for both the gully morphology and the observed changes without requiring liquid water.
Both outlets report the same core findings: the gullies appear active, their Earth-like appearance initially suggested water, and the researchers’ proposed driver is CO2 frost behavior. The articles primarily focus on the mechanism described in the arXiv preprint rather than providing new observational data or final peer-reviewed conclusions.
