Computer modeling of a giant impact that occurred 4.5 billion years ago has shown that the physical properties of early planets could have determined the scenario by which the Moon formed, infohub.kz reports.
A study by the Southwest Research Institute and the University of Arizona, covered by ScienceDaily, is the first to take into account the geological strength and temperature of the colliding bodies rather than treating them as purely liquid objects. Astronomers from the Southwest Research Institute (SwRI) and the University of Arizona simulated the collision of the early Earth with a hypothetical Mars-sized planet named Theia. The results were published in the journal The Astrophysical Journal Letters.
As lead author Adin Denton explained, the physical state and temperature of the protoplanets fundamentally change the scenario of the cataclysm. If the planetary bodies were sufficiently cold and strong, a single formed satellite could have emerged just five hours after the impact. In the case of higher temperature and lower material strength, Theia was completely destroyed, creating a massive debris disk around Earth from which the Moon gradually assembled.
Study co-author Erik Asphaug and SwRI vice president Robin Canup noted that accounting for rock strength offers a new perspective on the popular giant impact hypothesis. The modeling data help more precisely determine the Moon's age and the thermal state of the early Earth, but so far do not explain the identical chemical composition of both bodies. According to the researchers, Theia and proto-Earth could have formed from the same material in nearby regions of the young Solar System.