Astronomers are pretty sure they know where the Moon came from. In the early Solar System, a Mars-sized object dubbed Theia smashed into Earth. This cataclysmic collision knocked a huge mass of material into orbit, which coalesced and cooled into the Moon. But establishing exactly when this occurred is a difficult task. At the 55th annual Lunar and Planetary Science Conference (
Scott Alan Johnston is a science journalist whose work has been featured in Universe Today, Phys.org, SciTechDaily, and Inverse. He specializes in writing about astronomy, astrophysics, and space exploration, with a focus on discoveries and phenomena within our own solar system and beyond.