Galactic Passages May Have Shaped Earth's Early Continent Formation
A new study proposes that Earth's continents grew not only from internal geology but also as a result of the Solar System’s orbit through the Milky Way’s spiral arms, which could trigger bombardment by Oort Cloud comets and leave zircon isotope records across Archean cratons. While the timing of arm passages, meteorite impacts, and crustal signals show recurring correlations, the authors caution that this is not proven and suggest comparing Earth records with Moon/Mars data to test the idea.
