Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

Emily Simpson has loved space since she was a 10-year-old kid celebrating her birthday at a planetarium. Now a recent Florida Tech graduate, she leaves with not only a dual degree in planetary science ...

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 ...

NASA’s newly launched IMAP mission is set to tell us more about the boundary between our Solar System and interstellar space ...

A new Tatooine-like planet outside the solar system may orbit two failed stars, scientists reported Wednesday. Located about 120 light years away, the exoplanet appears to take an unusual path around ...

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 ...

(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 ...