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 ...

The boundary of a solar system is not defined by planets, but by gravity. Beyond Pluto and the Kuiper Belt lies the Oort Cloud, extending up to a light year from the Sun and still considered part of ...

New observations may offer fresh clues into how a giant exoplanet survived the violent death of its host star — and came to closely orbit its stellar remnants. The findings could serve as a preview of ...

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 dubbed ...