Astronomers studying extreme planetary systems have identified worlds so massive that they rival the smallest stars in size.

Theia, the world that helped form the Moon, came from the Solar System. Chemical clues in Earth and Moon rocks reveal this ...

Space has a knack for bending our sense of scale. The Moon feels close enough to touch—after all, we see its craters with ...

Some planets might produce their own water instead of relying on outside sources. In laboratory experiments, researchers simulated extreme conditions found within certain exoplanets by blasting ...