Astronomers studying the Kuiper Belt have detected a strange distortion that could point to an unknown planet lurking far beyond Neptune.

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

Dark matter refers to material that does not absorb, reflect, or emit any electromagnetic radiation. Astronomers have ascertained the existence of dark matter through the gravitational influence it ...

Astronomers have discovered a new member of a rare and mysterious class of solar system objects known as sednoids — a subset of extreme trans-Neptunian objects (ETNOs) with exceptionally distant, ...

Our solar system is a weird place. Much more than a home to eight planets, it’s filled with a myriad of fascinating other smaller bodies, including moons, asteroids, and comets. In recent decades, ...