Mom! The sun is following us!

Katherine exclaimed to her mom as they walked past the lake.

Katherine's mom laughed. 

I used to think that too! But it's actually spinning around us in an orbit!

Orbit? What's orbit?

Orbit is the way something moves around another object in space, like the sun around the earth, where we live.

Really? How do you know? Space is so far away!

Well, a long time ago, in the 1500s, an astronomer named Copernicus went over another's theories about space and decided they may have been a little off. 

He used math to figure out that the planets in space orbit-or revolve-around the sun. He even wrote a book about it! 

Later on, a man called Johannes Kepler discovered that planets moved in elliptical-or egg shaped motions-rather than circular  

I love eggs! 

Well that's a good way to remember! All of this happened during a certain age of time called The Scientific Revolution. 

The Scientific Revolution? What's that?