A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, scientists say.

On a frigid orbit beyond Neptune, some of the solar system’s smallest worlds project a strange silhouette. Two rounded lobes, pressed together with a narrow “neck,” like a snowman that never melted.

Planetary systems in the Milky Way galaxy tend to follow a particular pattern: rocky planets toward the center, closest to ...

The outer solar system begins where sunlight fades and distances stretch beyond everyday comprehension. This journey traces ...

A closer look at the planets around a star called LHS 1903 may just flip our understanding of how planetary systems form.

An international team of astronomers has discovered a distant planetary system that challenges long-standing theories of how ...

Six planets will shine together in the evening sky on Feb. 28. Here's how to get the best view before they disappear.

Astronomers have found a distant world that challenges planetary formation theory, with a rocky planet where gas giants should be.