This neat mockup from YouTube user Kudos was produced in Universe Sandbox 2, and displays what would happen if the Moon hit Earth head-on. In the simulation, the impact of the Moon sources Earth to turn into an uninhabitable ball of molten rock pretty rapidly. Each second in the video corresponds to sixty minutes of actual time, and it appears to be just a matter of hours till all life on Earth would possibly be vanished after the impact. Although it’s pretty cool, it’s perhaps not completely accurate. For one thing, there must be a huge chunk of Earth missing where the Moon hit. Consider that the Moon itself was possibly made by the subsequent debris blasted out from our planet when a Mars-sized object hit Earth 4.5 billion years ago or so. Still, it's fun to watch.