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 ...

We actually know very little about what's going on inside Uranus and Neptune, causing researchers to propose that these planets be called "rocky giants" instead.

Somewhere beyond Neptune, the Kuiper Belt is bent. Not by much, and not in a way any known planet can account for. A study ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

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 was touted more than a century ago. But ...

Neptune is the solar system's most distant planet, a cold, blue ice giant sitting nearly 30 times further from the sun than Earth. At that remote distance, temperatures plunge to nearly minus 200 ...

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 ...

A passing star, or a stellar flyby, with the potential to pull Neptune out of its orbit by just 0.1%, could mean catastrophe for the entire solar system. But don’t worry — it won’t happen in our ...

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 ...