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

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

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

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

WASHINGTON, May 30 (Reuters) - Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting ...

Forbes contributors publish independent expert analyses and insights. An award-winning reporter writing about stargazing and the night sky. The solar system suddenly has a new member. A new object ...

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

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

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 ...

Our solar system today has eight planets. Till a few years back, Pluto was our ninth planet, until it was demoted to a dwarf planet. But some studies suggest that the ancient solar system once still ...

If the solar system does have a Planet Nine, it is a world that was bullied by its larger siblings, exiled to the far reaches of space and only rescued from oblivion thanks to the intervention of ...