The outer solar system once seemed like a quiet backwater. But a glut of tiny, strange moons with unruly orbits are coming ...

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 ...

The hunt for Planet Nine continues as new discoveries make the Solar System’s biggest mystery even harder to solve. Is there ...

Using a new technique that partly relies on artificial intelligence, researchers spotted potentially more than 10,000 new exoplanets.

Our solar system may have hosted up to six giant planets in its first hundred million years, a new study suggests. The ...