Proper motion

Okie dokie! You know how everything around you moves? The sun, the moon, and even the stars move too! Proper motion is when astronomers measure how much a star moves over a long period of time.

Imagine you and your friend are playing a game of tag. Your friend moves quickly to the left, then to the right, and then runs toward you. They were moving a lot! It's the same with stars. They move around in different directions over time, and scientists can measure how much they're moving using telescopes.

But why do stars move? Well, they don't move because they're playing a game of tag, silly. Stars might look still in the sky, but they're all moving because they're a part of a galaxy. Do you know what a galaxy is? It's a big group of stars, just like how our family is a group of people.

Our galaxy is called the Milky Way, and it's made up of billions and billions of stars! Each star has its own path that it follows as the Milky Way spins. As a result, some stars move away from us, and others move closer to us over time. So scientists measure how much a star moves (proper motion) to understand their paths and really get to know them better.