The mysterious Oort cloud is the source of many of our solar system's comets, but astronomers still have no idea what it ...

But in the grand scheme of the solar system, Earth's Moon isn't as big as you might think. Oberon is Uranus’s second-largest ...

Researchers claim that there could be at least 1 million interstellar objects hiding in the Oort Cloud at the edge of our ...

A rare full seven-planet alignment will be visible in the early night sky between Feb. 22 and 28. We have the tips you need ...

This week, decipher clues from the world’s oldest rune stone, see the ethereal glow of birds-of-paradise, watch a light show at the heart of the Milky Way, and more.

The $488 million observatory is set to launch at the end of this month on a two-year mission to map the entire celestial sky.