Astronomy is the study of outer space and everything that’s out there and part of our universe. We study the universe because we are part of it. It’s our home. We live on earth, a rock that orbits around the sun, just one of billions of stars out there in the universe.

It wasn’t until the 1600s that people started to understand the universe better. People used to think that earth was the center of everything in the universe. A scientist named Galileo noticed that Jupiter had moons that circled around it. Using a telescope, he showed that not everything circled the earth the way people had thought.