Astronomers have witnessed evidence of an extremely violent collision between planets, and it resembles the event in Earth's history that created the moon.

Astronomers have finally pinned down both the mass and distance of a solitary “rogue” planet, a world that drifts through space without the warmth or light of a parent star. The object, a Saturn-sized ...

Astronomers have, for the first time, pinned down both the mass and distance of a planet that drifts through the galaxy without a parent star, turning a once purely theoretical class of worlds into a ...