Cassini Crater in the southern Martian highlands
Cassini Crater in the southern Martian highlands
Cassini Crater, which measures 415 kilometres across, is situated at 30 degrees east and 25 degrees north, in the highland region of Arabia Terra. It was named after the eminent Italian-French astronomer Giovanni Domenico (Jean-Dominique) Cassini (1625–1712). It is a very old crater that has been heavily levelled by erosion. Due to their immense size, such craters are also described as impact basins. Cassini’s bowl-shaped depression is filled with layers of sediment that are several kilometres thick, and the crater rim, which once rose two to three kilometres high, has already been severely eroded. Scientific research indicates that at one time the Cassini depression was covered with standing water, as is also thought to have been the case for some of the other craters in the vicinity. The amount of water in Cassini Crater would have been roughly equivalent to the volume of Lake Baikal in Siberia, which is the largest freshwater lake on Earth.