Far beyond Neptune, strange orbital patterns suggest the Solar System may still contain a massive unseen planet. Planet 9 ...

Astronomers surveying the outer solar system have revealed that a rare object far beyond Neptune is moving in sync with the eighth planet in an unexpected way. Called 2020 VN40 and first discovered in ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

What is Planet Nine, and where is it? This question remains one of the biggest mysteries in astronomy. Researchers believe a giant planet may be hidden far beyond Neptune in the distant regions of the ...

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 ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

Mission concepts to the outer solar system are relatively common, as planetary scientists are increasingly frustrated by our lack of knowledge of the farthest planets. Neptune, the farthest known ...

Astronomers in Japan have spotted a distant object orbiting the Sun far beyond Neptune, pointing to an extraordinary event that took place during the earliest years of the solar system. Astronomers ...

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 — ...