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 ...

Humanity has already sent five spacecraft on trajectories that will eventually carry them beyond the Solar System, ...

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

Add Yahoo as a preferred source to see more of our stories on Google. An image of WISPIT 2 taken by the Very Large Telescope in Chile. Astronomers have just found a second gas giant recently formed ...

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

Astronomers have uncovered a massive new trans-Neptunian object, 2017 OF201, lurking at the edge of our solar system. With an orbit stretching 25,000 years and a size that may qualify it as a dwarf ...

Jupiter's giant moon Ganymede is the only known moon to have its own magnetic field — and it may be heating up in a process "not yet observed anywhere else," new research suggests. This standout ...