Deimos, the smaller and outermost of Mars' two moons, is roughly oval in shape and has a deep depression at its south pole. Unlike its heavily scarred sister moon, Phobos, Deimos is covered by a loose layer of dust and rubble—a so-called regolith layer—which gives it a smoother, dustier appearan...
Source: [Phys.org](https://phys.org/news/2026-08-asteroid-impact-mars-moon-deimos.html)