Though the planets are always “aligned,” seeing more than four in the sky is more uncommon. February’s lineup is a chance to ...

Earth is home to some truly bizarre and breathtaking landscapes — here are 20 that look straight out of an alien world.

The study analyzed the circumstellar disks of a pair of stars, learning about how planets are formed from some unexpected ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...