Astronomy Fun Fact #42
There are many ways to determine the age of a star, but none are as accurate or as cool as the way we determined the age of the Sun.
The Sun is ~4.5 billion years old, which we learned by radioactive dating meteorites from space. That means we're basically looking at ratios of different particles in space rocks to figure out how long the particles have been interacting with each other.
"Why can't we just date rocks from Earth this way?" you might ask. Good question! We can't use Earth rocks for this because rocks on Earth are constantly being recycled by tectonic plate movement. So the rocks on the surface aren't actually as old as the planet itself!