Transit of Phobos from Mars

Phobos transits the Sun, as viewed by the Perseverance rover on 2 April 2022

A transit of Phobos across the Sun as seen from Mars takes place when Phobos passes directly between the Sun and a point on the surface of Mars, obscuring a large part of the Sun's disc for an observer on Mars. During a transit, Phobos can be seen from Mars as a large black disc rapidly moving across the face of the Sun. At the same time, the shadow (antumbra) of Phobos moves across the Martian surface.

The event could also be regarded as a particularly quick and shallow annular solar eclipse by Phobos.