One punch or several crashes: how did the Moon form?

Scientists have proposed that the Moon formed from objects crashing into Earth repeatedly NASA / Handout / Getty The Earth and its constant companion, the Moon, have a very similar make-up, something that has long puzzled scientists when it comes to deciding how the satellite planet formed. One prevailing hypothesis suggests the Moon was formed when it splintered off in a single, giant impact between Earth and another object in the Solar System. Raluca Rufu, of the Weizmann Institute of Science and co-author of the new study, said: “The multiple impact scenario is a more ‘natural’ way of explaining the formation of the Moon.” In order to investigate the theory, Rufu and a team of scientists created nearly a thousand computer simulations between a proto-Earth and embryonic planets, named planetesimals. "In the early stages of the Solar System, impacts were very abundant, therefore it is more natural that several common impactors formed the Moon rather than one special one," Rufu told AFP. Writing in an accompanying comment piece on the study in Nature Geoscience, Imperial College London researcher Gareth S Collins said: “Building the moon in this way takes many millions of years, implying that the Moon’s formation overlapped with a considerable portion of Earth’s growth.” However, he believes more understanding is needed of how the moonlets formed and merged efficiently in order to build the Moon and to fully discard the single-crash theory, saying: “For final adjudication, we must now look to firmer evidence on each side.” This article was originally published by WIRED UK