The majority of stars in our galaxy are home to planets. The most abundant are the sub-Neptunes, planets between the size of Earth and Neptune. Calculating their density poses a problem for scientists ...

For decades, Uranus and Neptune have carried the tidy label of “ice giants,” shorthand for worlds built mostly from frozen ...

For generations, school posters have sorted the Solar System into tidy boxes: four small rocky planets near the Sun, two huge ...

New models suggest Uranus and Neptune may hold far more rock than expected, raising questions about how these distant planets formed.

If you look at our Solar System, there’s a sharp divide between the four rocky planets and the large “ice giants” of the outer Solar System, Uranus, and Neptune. The divide isn’t only a matter of ...