Long ago, one Greek scientist thought the stars were floating crystals. Some people believed that the sun was a flaming chariot driving through the sky. And for many years, people were certain that Earth was the center of the universe and all the stars and planets spun around us.

As time passed, these legends were replaced by the science called astronomy. We know that Earth is just a small piece of rock traveling through a vast realm of space. And that our sun is just one of billions of stars. But even with powerful telescopes, satellites and rockets, there are still questions to be answered about the endless expanse called the universe.

That's why Don't Know Much About® the Solar System is here, to ask and answer the questions you may have about our own star - the sun - and the planets that revolve around it.