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 ...

Jupiter, the largest planet in the solar system, was 2 to 2.5 times bigger in its earlier life, according to new research. Credit: NASA / JPL-Caltech / SwRI / MSSS / Tanya Oleksuik Jupiter, the ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

Astronomers have discovered more than 300 exoplanetary systems that have three or more known planets. Most of these planets are about the same size and spaced close together, earning them the moniker ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...