[MUSIC] Joan Cartan-Hansen,Host: Look at the Milky Way.

Have you ever wondered where our solar system is inside this galaxy?

Let's start with a place we know best: the Earth.

The Earth rotates around the Sun in our solar system.

But our sun is just one star out of billions of other stars that make up our galaxy, the Milky Way.

Scientists think our solar system is located near the outer edge of the galaxy, in one of its spiral arms.

Scientists have discovered there is a supermassive black hole at the center of our galaxy.

And everything in our galaxy orbits around this black hole.

So, how many stars and solar systems are there in our galaxy?

Well, scientists don't really know.

They've spent years mapping what's out there.

The hope is the more we learn about our own galaxy, the more we can understand about all the others.

But there's more to the universe than our galaxy.

The Milky Way is just one among billions of other galaxies that make up the known universe.

And that's a lot of space.

For more information about galaxies, check out the Science Trek website!

You'll find it at science trek dot org.