The probe will orbit the sun "close enough to pass inside a solar eruption, like a surfer diving under a crashing ocean wave, ...

Astronomers are investigating the possibility of a hidden ninth planet beyond Neptune, which could explain unusual orbital patterns in the Kuiper Belt.

After a decade-long search, some scientists say a growing number of clues point to the existence of a hidden planet in the ...

Tiny grains from a distant asteroid are revealing clues to the magnetic forces that shaped the far reaches of the solar ...