Add Yahoo as a preferred source to see more of our stories on Google. Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than ...

The Solar System has 8 planets, and each one is different. Earth has 5 oceans, thick air, forests, rivers, and more than 1.5 ...

One night last fall, University of Cincinnati astrophysics graduate Paul Smith waited anxiously for data to start rolling ...

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, waiting to ...