There's no shortage of round celestial objects in our universe. Planets, moons and stars all exhibit lovely spherical shapes.

Astronomers have explained how a galaxy cluster maintains its heat, despite emitting X-rays that cool the hot gas at its center. The group discovered the existence of a fast-moving, high-temperature ...

This month's night sky is filled with close-range meteors, swirling nebulas, and prime stargazing conditions. Here’s when you ...