OtterKnow Kids EncyclopediaHave you ever looked up at the Moon and wondered where it came from? Scientists think that a long, long time ago — before there were any people, animals, or even dinosaurs — something huge happened that made our Moon!
About 4.5 billion years ago, Earth was still very young. A huge space rock about half the size of Earth came flying through space and crashed right into our planet! Scientists call this space rock Theia. The crash was so big and so hot that it broke apart rocks and sent huge pieces flying up into space all around Earth. The pieces made a giant ring around our planet, a little bit like the rings around Saturn.
Over time, all those floating pieces of rock started bumping into each other and sticking together. Gravity pulled them closer and closer until they formed one big ball — our Moon! When the Moon first formed, it was much closer to Earth than it is now. It was also covered in hot, melted rock. Slowly, it cooled down and moved farther away to where we see it today.
Here is something really cool — scientists are not completely sure this is exactly what happened! They have found clues by studying Moon rocks that astronauts brought back to Earth. Those rocks are made of the same stuff as Earth rocks, which makes scientists think the Moon really did come from a big crash.
But some of the clues do not fit perfectly yet. Scientists have lots of ideas about exactly how it happened, and they are still working to figure it out. That is one of the exciting things about science — there is always more to discover!
- The crash that may have made the Moon happened about 4.5 billion years ago — that is before anything was alive on Earth!
- Right after it formed, the Moon was about 15 times closer to Earth than it is now.
- The Moon is still moving away from us a tiny bit every year — about as far as your fingernail grows!
- Twelve astronauts have walked on the Moon and brought back rocks that help us understand how it was made.
