Computer simulations show that a single oblique impact can explain two of the most defining geological features of Deimos, the smallest moon of Mars. The findings, reported by S. D. Raducan and colleagues in Nature Astronomy, indicate that one collision carved the moon's south-polar depression and blanketed its surface in regolith. The results also reveal that Deimos possesses an interior structure similar to recently visited asteroids.
Modelers based their pre-impact reconstruction on a high-resolution shape model of Deimos published by C. M. Ernst and colleagues in 2023, derived using stereophotoclinometry. The collision dynamics draw on previous research into asteroid structures, including a 2020 artificial impact experiment led by M. Arakawa on the asteroid (162173) Ryugu. That experiment produced a crater within a gravity-dominated regime, showing that Ryugu had an unexpectedly low-strength rubble pile surface.
Scientists will evaluate the impact model's predictions using data gathered from future spacecraft. A 2022 review by K. Kuramoto and colleagues highlighted the upcoming Martian Moons eXploration mission, or MMX, which plans to conduct close-range observations of Deimos and return physical samples from Phobos to investigate how habitable planetary systems and their moons form.
Springer Nature published the peer-reviewed study on August 28, 2026, summarizing earlier research by Raducan's team on subcatastrophic impacts. The publisher offers individual article PDF access for $39.95, alongside a digital Nature+ subscription priced at $32.99 for 30 days. An annual digital and print subscription to the journal costs $119.00 per year, covering 12 digital issues at $9.92 per issue.
