The way people think of the Solar System has changed many times throughout history. Before the development of the telescope, these ideas were based on what could be seen with the naked eye.

In fact, every planet—and every moon—in the solar system will be in the sky during the eclipse. However, that doesn’t mean you’ll see them all. Contrary to what you might have read ...

There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond the eighth planet Neptune. The tantalizing prospect of a ninth ...