It was a threshold crossed in the deepest reaches of space: A spacecraft launched from Earth has now entered new and unexplored territory that may or may not be outside our solar system. A press ...

Astrophysicists are mapping a vast, hidden structure in space that appears to guide matter and radiation along a kind of interstellar highway stretching from our solar neighborhood to distant stars.

The Voyager spacecraft, on a decades-long journey of exploration, have made an unusual discovery at the edge of our solar system. They’ve detected a layer of hot plasma at the solar system’s boundary, ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...