A powerful new observatory is the best hope yet for finding the elusive Planet 9, a large planet that some scientists say is ...

Mars is about 140 million miles from our cozy planet. A human mission to that cold, rocky neighbor would mean being away from Earth for about 3 years. But the things those explorers would see and ...

U.S. team of researchers detected signs of two chemicals in the planet's atmosphere long considered to be "biosignatures" ...

Further studies are needed to determine whether K2-18b, which orbits a star 120 light-years away, is inhabited, or even ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there ...