Everyone knows about the Solar System, and the planets that make it up. They’re in space, orbiting the Sun, in an order we all at least used to be able to recite. But it was not always so.

With a radius of 3,959 miles, Earth is the fifth largest planet in our solar system, and it's the only one known for sure to have liquid water on its surface. Earth is also unique in terms of ...

Narrator: Further from the Sun, in the outer reaches of the solar system, we find the gas planets. Much larger than the rocky planets, these cosmic giants are accompanied by numerous moons.

Try stargazing. Need a new idea to keep kids entertained? Try stargazing. Free learning activities and videos about the solar system Free learning activities and videos about the solar system Free ...