Overview
- A peer-reviewed paper in Nature Astronomy concludes that one large asteroid about 320 meters wide striking at roughly a 45° angle can produce Deimos’s deep southern basin and its smooth, dusty surface.
- The team matched high-resolution images from ESA’s Hera flyby with about 100 Smoothed Particle Hydrodynamics simulations to find the scenario that best reproduces observed features.
- Simulations show the impact would have lofted material that fell back as a near-global blanket of regolith up to about 200 meters thick while leaving outlines of older, buried craters intact.
- The modeled behavior requires a highly porous, rubble-pile interior for Deimos because a stronger, solid body would have transmitted shocks that erased older surface features.
- The study gives concrete, observable predictions that JAXA’s MMX mission, arriving at the Martian moons in 2027 and returning Phobos samples in 2031, can use to confirm the impact model and clarify the moons’ origins.