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 ...

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

A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, scientists say.

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 ...

Astronomers have found new evidence that a mysterious ninth planet may be hiding at the edge of the solar system - rewriting what we know about the cosmos again. An international team from Taiwan, ...

All of our solar system’s planets are lining up in the night sky at once this week. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a great ...

(CNN) — 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 ...