The linear depression in this VIS image is part of Sirenum Fossae. Depressions of this type are called graben, which form by the down drop of material between two parallel faults. The faults are caused by tectonic stresses in the region. The Sirenum Fossae graben are 2735km (1700 miles) long. Orbit Number: 84379 Latitude: -32.7135 Longitude: 204.562 Instrument: VIS Captured: 2020-12-22 01:06 https://photojournal.jpl.nasa.gov/catalog/PIA24398