Astronomers have found a distant world that challenges planetary formation theory, with a rocky planet where gas giants should be.

A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, ...

We know that our Solar System is not the blueprint for all planetary systems out there. There are gas giant planets orbiting ...

Scientists say a nearby red dwarf star hosts a planetary lineup that looks like a mirror image of our own solar system, with ...

A newly studied solar system breaks the usual planet pattern, raising fresh questions about how rocky and gas planets form.

Astronomers have found a rocky planet where it should not exist, orbiting far from a cool red star. Could this strange ...

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 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, ...