Mare Serpentis snake pit 🔴 The Mare Serpentis region (Latin for Sea of the Snakes) is located northwest of the giant Hellas impact basin on Mars and was named after the constellation Serpens in the northern celestial hemisphere. This Mars Express observation shows impact craters of different ages, randomly distributed on the surface. The younger craters in the image show more distinct crater rims, the older ones appear much more smoothed and eroded. Especially peculiar are the different interior fillings of the craters. The surface patterns in these craters reflect the climatic conditions in which the fillings were formed, providing an insight into the history of the Martian climate. The largest impact crater in the image shows a width of 45 km, strongly eroded crater rims, a flat floor with some interesting erosional features and a very eye-catching dark color. Interestingly, all craters on the right side of the image show this dark color, presumably created by dark sands, transported by wind. In the lower left portion of the first image, a 35 km impact crater gives interesting insights into the subsurface. Here, an approximately 20 km long, 9 km wide and several hundreds of meters deep pit opens and exposes different alternating layers in the subsurface. Some of the layers appear to be composed of brecciated materials. The curvilinear form of a prominent fault inside the pit suggests a formation by collapse. This kind of collapses are known to happen in volcanically active regions where ancient lava tubes or magma chambers emptied and as a consequence created voids in the underground which later collapsed. The region in and around Mare Serpentis is known to have been volcanically active in the past. 📸 @europeanspaceagency/ @germanaerospacecenter/ @fu_berlin; @creativecommons CC BY-SA 3.0 IGO 📸 @NASA/MGS/MOLA Science Team #Mars #RedPlanet #MarsExpress #CreativeCommons