Scientists from Durham University's Institute for Computational Cosmology employed the most thorough supercomputer simulations available to uncover an alternate scenario for the Moon's formation, with a massive impact instantly launching a Moon-like rock into orbit around Earth. In their quest for scenarios that may explain the current Earth-Moon system, the researchers simulated hundreds of possible collisions, altering the angle and speed of the crash as well as the masses and spins of the two impacting bodies. These computations were carried out using the SWIFT open-source simulation code, which was hosted by Durham University on behalf of the DiRAC High-Performance Computing facility.
The increased processing capability indicated that lower-resolution simulations might overlook critical elements of large-scale collisions, allowing researchers to identify traits that were previously unavailable for investigation. Only high-resolution simulations created the Moon-like satellite, and the added detail revealed how its outer layers were richer in Earth-derived material. If most of the Moon formed quickly after the massive impact, it is possible that less of it got molten during creation than in the usual theories in which the Moon evolved within a debris disk around Earth. These theories should anticipate diverse interior structures for the Moon depending on the circumstances of the following solidification.
According to Vincent Eke, co-author of the paper, this creation process might help explain the closeness in isotopic composition between the lunar rocks returned by the Apollo astronauts and the Earth's mantle. There may also be visible effects on the thickness of the lunar crust, allowing us to narrow down the sort of impact that occurred.
Furthermore, they discovered that even when a satellite travels so near to the Earth that it is anticipated to be ripped apart by the "tidal forces" of Earth's gravity, the satellite can not only survive but also be propelled into a larger orbit, secure from future destruction.
The Moon is assumed to have originated as a result of a collision between the early Earth and a Mars-sized asteroid named Theia 4.5 billion years ago. According to most beliefs, the Moon is formed by the steady buildup of debris from this collision. However, examinations of lunar rocks suggest that their composition is similar to that of Earth's mantle, whereas the collision yields largely Theia-derived debris. This immediate-satellite scenario expands on the projected composition and internal structure of the Moon, as well as its early lunar orbit. The numerous planned lunar missions should give new clues about what type of massive impact created the Moon, which will inform us about Earth's history.
Scientists from NASA Ames Study Center and the University of Glasgow, UK, were part of the research team, and their simulation findings were published in the Astrophysical Journal Letters.
Journal Information: J. A. Kegerreis et al, Immediate origin of the Moon as a post-impact satellite, Astrophysical Journal Letters (2022). www.hou.usra.edu/meetings/lpsc2022/pdf/1724.pdf