Here is a kid friendly explanation about when Earth formed and how scientists know it.
- What created means here: scientists say Earth formed, not created by someone, from dust and rocks in the early solar system.
- Numbers: Earth formed about 4.54 billion years ago. That is a very long time ago and shows how old our planet is.
- How we know: scientists study rocks on Earth and meteorites from space. They use radiometric dating to measure how elements decay and estimate ages.
- How Earth formed: tiny bits of dust in the solar nebula stuck together, grew into bigger rocks, and gravity pulled them into a growing Earth. Heat from impacts melted some of it and helped separate into core, mantle, and crust.
- Moon origin: a big collision long ago threw debris into space that formed the Moon, about 4.5 billion years ago.
- Big picture: the Universe is about 13.8 billion years old; Earth is younger, about 4.5 billion years old.
In short, Earth is very old and formed from space dust long ago, and scientists learn its age by studying rocks and space material.