A massive interstellar object passing through our solar system during its formative years likely altered the orbits of planets into trajectories observed today, a new study says. Interactions with ...

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 ...

Beyond Pluto lies a collection of frozen worlds that challenge traditional ideas of what planets should be. This episode ...

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

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 ...

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 ...

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 ...

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, ...