01/08/2025
While the giant-impact theory explains many lines of evidence, some questions are still unresolved, most of which involve the Moon's composition.[55] Models that have the Moon acquiring a significant amount of the proto-earth are more difficult to reconcile with geochemical data for the isotopes of zirconium, oxygen, silicon, and other elements.[56] A study published in 2022, using high-resolution simulations (up to 108 particles), found that giant impacts can immediately place a satellite with similar mass and iron content to the Moon into orbit far outside Earth's Roche limit. Even satellites that initially pass within the Roche limit can reliably and predictably survive, by being partially stripped and then torqued onto wider, stable orbits.
