At first glance, the night sky appears still. But in reality, everything moves, our Solar System being no exception. As it drifts along the Milky Way, it encounters unseen forces—dense clouds of ...

"These objects really could be anywhere in the solar system at any given time." One million alien visitors from another star system could already be lurking in the solar system. We aren't talking ...

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.