10 Nov 2016

The mystery of Mare Orientale, a gigantic multi-ring impact crater on the southwest edge of the Moon has been revealed

The mystery of Mare Orientale, a gigantic multi-ring impact crater on the southwest edge of the Moon has been revealed. Thanks to the data collected by NASA's GRAIL mission, a team of researchers from Brown University has been able to show us the details of the internal structure of the basin by recreating a computer model of the ring formation process.

Scientists have measured the transient cavity, meaning the crater initially generated by the impact, discovering that it is located between the two innermost rings and has a diameter of approximately 300-500 kilometres. A second study then provided details on the object that hit the surface. Estimates say that it had a diameter of approximately 60 kilometres and was travelling at a speed that touched 15 kilometres per second. After the collision, the crust rebounded, creating an inward flow of hot, fluid rocks. This phenomenon caused rifts in the crust, giving rise to two external rings.

The inner ring, on the other hand, was created by material that spilled out following the collision, placing itself in circular shape. The conclusions of the two studies will make it possible for scientists to analyse a series of similar craters on Mars, on Earth and on other bodies in the Solar System. The Moon is a geologically inert body. It is therefore possible, like in a laboratory, to make a very accurate analysis of a series of characteristics that are also present elsewhere in our system, but that are better preserved on the Moon.