Astronomers have observed a planetary system that challenges current planet formation theories, with a rocky planet that ...

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 ...

Scientists have been trying to find a hypothetical Planet 9 that may exist outside our known solar system based on the unusual orbits of certain dwarf planets. But those orbits might not require a ...

At the farthest edges of the solar system, strange objects follow paths that defy easy explanation. This story investigates ...

A newly studied solar system breaks the usual planet pattern, raising fresh questions about how rocky and gas planets form.

From meteorites that impact Earth, to a moon that orbits backwards... From meteorites that impact Earth, to a moon that orbits backwards, to an imposter lurking in the asteroid belt, a variety of ...

Astronomers at Princeton University have uncovered evidence that the outer solar system is more structured than long believed. Led by astrophysics doctoral student Amir Siraj, the research points to a ...

EVANSTON, Ill. — Except for the fact that we call it home, for centuries astronomers didn’t have any particular reason to believe that our solar system was anything special in the universe. But, ...

The Sun is an incandescent but benevolent dictator. For billions of years, it’s kept our star system well organized through the influence of its powerful gravity. All the planets revolve around it on ...

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...