Thankfully, the Theia impact did not destroy the planet; the combined gravitational wells of Theia and proto-Earth were sufficient to retain 98.8% of their combined mass inside their Roche limit. The remainder escape to form the moon by orbital accretion. The impact energy was slightly lower than the gravitational binding energy of Earth, and while it melted the majority of Earth’s crust, some portions of the crust on the other side of the planet survived partially intact.