Crisp Crater in Sirenum Fossae

June 03, 2015

This impact crater appears relatively recent as it has a sharp rim and well-preserved ejecta, the material thrown out of the crater when a meteorite hit Mars. The steep inner slopes are carved by gullies and include possible recurring slope lineae (known as RSL) on the equator-facing slopes. RSL could be a sign that water, its freezing point lowered by a high concentration of salt, could be seeping down these steep slopes. MRO has seen RSL appear in warmer seasons and disappear in cooler seasons in a few locations on Mars, indicating a planet with plenty of active processes.