Uranus and Neptune may be 'rock giants,' not 'ice giants,' new model of their cores suggests

Neptune (left) and Uranus (right) might be rockier than they seem.

The interiors of Uranus and Neptune may be rockier than scientists previously thought, a new computational model suggests — challenging the idea that the planets should be called "ice giants."

The new study, published Dec. 10 in the journal Astronomy & Astrophysics, may also help to explain the planets' puzzling magnetic fields.