Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

CAPE CANAVERAL, Fla. — Astronomers have discovered a rare solar system in the Milky Way that boasts six planets orbiting in perfect rhythm like a cosmic orchestra, untouched by outside forces since ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system ...

CAPE CANAVERAL, Fla. (AP) — Astronomers have discovered a rare in-sync solar system with six planets moving like a grand cosmic orchestra, untouched by outside forces since their birth billions of ...

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 dubbed ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

There are 8 planets in our solar system. The planets orbit the Sun in elliptical trajectories, and they are all different in size, composition, temperature, and characteristics. The planets can be ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. Astronomers have found a distant celestial body — ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...