What is mare crisium?

Mare Crisium, also known as the "Sea of Crises," is a large lunar mare (a dark, basaltic plain) located on the Moon's eastern hemisphere. It is situated in the northeastern part of the Moon's near side and is the third-largest lunar mare, covering an area of approximately 530,000 square kilometers.

Mare Crisium is notable for its relatively small size and circular shape compared to other lunar maria. It is surrounded by a ring of mountains and ridges, which were likely formed by the impact that created the mare. The central peak in the middle of Mare Crisium, known as the central peak, rises to a height of over a kilometer and is thought to have formed during the impact event.

Mare Crisium is one of the few lunar maria that is not covered in a thick layer of dark volcanic basalt, giving it a lighter appearance in contrast to other maria on the Moon. The mare is thought to be relatively young, with some estimates suggesting it formed around 3.9 billion years ago.

Mare Crisium has been the landing site for several spacecraft, including the Soviet Luna 24 mission in 1976, which returned a sample of lunar soil from the mare to Earth. The region has also been studied extensively by a number of lunar orbiters and remote sensing missions.