Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

Our solar system’s origin story spans billions of years and involves clouds of gas, cosmic collisions, and planetary ...

In the cold, dark outskirts of planetary systems far beyond the reach of the known planets, mysterious gas giants and ...

A new analysis of planet formation models estimates the odds of a theoretical Planet Nine orbiting our sun at 40% given ...

The chance of a planet forming in the outer reaches of the solar system - a hypothetical Planet Nine - could be as high as 40 ...

A new study may finally explain how planets can end up orbiting their stars at extremely large distances—sometimes hundreds ...

The presence of water-ice in the debris disk around a young star could have helped facilitate the growth and development of ...

A recent study found that Jupiter was once twice the size that it is now, making it big enough to swallow up 2,000 Earths.

A new study from the University of Arizona reveals an unexpected way that planets' cores might form in our solar system.

The lone planet confirmed to be in the system is squeezed in between the two, orbiting at a distance similar to Earth's ...