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 ...

Scientists have uncovered a surprising way to study the harsh space weather around young M dwarf stars. Mysterious dips in ...

Add Yahoo as a preferred source to see more of our stories on Google. A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than the ...

LONDON — 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 ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics but collectively believed to be ...