Sesquinary reimpacts dominate surface characteristics on Phobos

- Sesquinary mass influx is capable of significant impact to the surface geology of Phobos. This can exceed the flux of solar system impactors.
- Sesquinary impacts have likely controlled the surface properties of Phobos for the last 20-25 million years.
- The top ∼30 cm of Phobos regolith may largely consist of reaccreted sesquinary ejecta material.