how do we know how old the earth is

Question: how do we know how old the earth is
- Keywords:
  earth
Asked by anon-328552 on 20 Jun 2022.
- Elena Field answered on 20 Jun 2022:
  
  We know this by looking at rocks! Some of the rocks on Earth have been dated to 3 Billion years old, and we can also match the chemicals and minerals in rocks to meteorites that have landed on earth and learn more that way.
  This is how we estimate how long ago the planet was formed, when the moon was formed and when global events took place millions of years ago (such as when the dinosaurs lived and became extinct).