Even at a glance, the planets in our solar system are wildly diverse. Huge and small, airless and densely packed with ...

A strange planetary system called TOI-201 is changing in real time, with three very different worlds pulling on each other.

Astronomers have discovered a remarkable planetary system where three very different objects orbit a distant star—and their ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labelled as planet X, prominent astronomers ...

The idea of a planet orbiting two suns has long captured both scientific curiosity and public imagination. Popularised by ...