Our moon has a violent past that just got a little more fearsome.
Planetary formation is not for the weak of heart. Building a planet from countless grains of dust and tendrils of gas is a violent process of colliding, coalescing, and melting into bigger and bigger rocks. Our Earth was a decently-sized world when it took one final hit: a Mars-sized object smashed into our home planet.
We used to think this object, Theia, struck a glancing blow and was captured into Earth orbit as our n