Space & Astronomy

Uranus and Neptune may be lava giants, not ice giants, study finds

By T.K. Randall
June 28, 2026

Image: Uranus and its Moons
Credit: NASA / JPL / (PD) Uranus is perhaps the most unique of all the planets in our solar system thanks to its peculiar tilt which sees it rotate on an axis set almost 90 degrees off of the orbital plane of the Sun.

Beyond it, Neptune, which is 17 times the mass of the Earth, exhibits a distinctive blue color to the naked eye due to traces of methane in the outermost parts of its atmosphere.

Ever since Pluto was demoted from planet status, these two mysterious and distant worlds have represented the outermost planets in our solar system.

Most of what we know about them comes courtesy of the Voyager probes, but no other missions have gone there since, meaning that there is a lot we have yet to understand about them.

Now, a new study has offered up the possibility that one of the most fundamental aspects of these worlds - that they are 'ice' giants - may be completely wrong.Instead, there is a chance that they may in fact have an ocean of magma on the inside.

This means that rather than being ice giants, they may be magma-ocean giants.

The research, which was conducted by a team of researchers from the University of California, used new models to show that a lava ocean could account for existing observations of these worlds.

The team found that, at high enough pressures, hydrogen gas can dissolve to form magma.

While this doesn't prove that Neptune and Uranus really do have magma oceans, it further emphasises just how little we actually do know about these enigmatic planets.

Further exploratory missions will likely be needed for us to find out for sure one way or the other.

Source: Gizmodo

Tags: Neptune, Uranus