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 ...

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, ...

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 ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked ...

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 ...

(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 ...