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 ...

China advances plans for dual solar system boundary missions China has published coordinated papers outlining dual missions ...

The official number of exoplanets—planets outside our solar system—tracked by NASA has reached 6,000. Confirmed planets are added to the count on a rolling basis by scientists from around the world, ...