There may be an undiscovered planet in the outer solar system whose presence is revealed by the strange orbit of objects beyond the eighth planet Neptune. The tantalizing prospect of a ninth ...

We have discovered thousands of exoplanets in the last few decades, while the number of planets in the Solar System has remained at eight – but our discovery of more might not yet be over.

2 of the unusual asteroid, complete with an official name: 2018 CN41. But less than 17 hours later, the Minor Planet Center ...

The organic material found in a few areas on the surface of dwarf planet Ceres is probably of ... on trans-Neptunian objects, comets, and far-away asteroids. These bodies are thought to be largely ...

A planet-size object that possibly once visited the solar ... than Mars' current orbit of 1.5 AU from the sun. The simulations show that just one substellar object flyby was sufficient to alter ...