We know that our Solar System is not the blueprint for all planetary systems out there. There are gas giant planets orbiting closer to their stars than Mercury, and rocky worlds much larger than Earth ...

Surprised astronomers said Thursday they have discovered a star with planets in a bizarre order that defies scientific expectations – and suggests these faraway worlds formed in a manner never seen ...

Scientists say a nearby red dwarf star hosts a planetary lineup that looks like a mirror image of our own solar system, with ...

An inside-out planetary system around the star LHS 1903 is turning everything that astronomers know about planet formation upside down.

When you see art of our solar system as the planet orbit the sun, you may notice that Earth's orbit has a tilt. It is not a perfect circle. What's more, Earth is not the only planet that displays such ...

The planetary system, located 120 light-years away, features four worlds orbiting a red dwarf star and challenges classical formation schemes.

For decades, scientists have believed that planetary systems typically form with rocky planets close to their star and gas-rich planets farther away. This discovery questions their knowledge.

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

LONDON — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper's authors have ...