Hydrae Chasma is a deep, circular depression on Mars approximately 50 kilometers across, situated between Juventae Chasma to the north and the large canyon system Valles Marineris to the south. The Chasma has steep walls flanked by numerous landslides and a massive scarp along its southern boundary where the surface has collapsed into this depression. - Image: NASA/JPL/University of Arizona

Caption: Ginny Gulick