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, ...

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

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

Astronomers have found a compact solar system whose planets line up in a way that, according to current models, should not be possible. Around the small star LHS 1903, a dense rocky world orbits on ...

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 ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

The James Webb Space Telescope has captured its first direct images of carbon dioxide in a planet outside the solar system in HR 8799, a multiplanet system 130 light-years away that has long been a ...

For millions of years, a frozen wanderer drifted between the stars before slipping into our solar system as 3I/ATLAS—only the ...

Mercury is the smallest planet in our solar system. Explore its size, extreme temperatures, core structure, and comparison with Pluto.

(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 ...