Humans might not know of any intelligent beings beyond Earth, but if they exist, they might already know about us. New ...

Before defining what a light-year is, we should define what a light-year is not: It is not a measure of time, but rather a ...

A galaxy that has remained unchanged for 7 billion years — a rarity in the universe — has been observed by astronomers, ...

Gravitational waves from most massive black hole collision ever observed challenge existing theories, as scientists suspect ...

The new galaxy, because of how far away it is, looks to observers exactly as it did when it was first created 3 billion years ...

We live in a world defined by inches, feet and miles (or centimeters, meters and kilometers, if you prefer), and it’s not difficult for most of us to ...

NASA astronomers have confirmed what may be the greatest discovery of the era. They found a significant reservoir of water that was hidden in the cosmos, and that surrounds a quasa ...