Research by the University of Zurich Are Uranus and Neptune more boulders than ice giants?
New research suggests that Uranus and Neptune may be rocky rather than icy
Image: dpa
Possibly rockier than thought: the planet Neptune (archive image)
Image: dpa
New research suggests that Uranus and Neptune may be rocky rather than icy
Image: dpa
Possibly rockier than thought: the planet Neptune (archive image)
Image: dpa
Uranus and Neptune are giant planets at the edge of our solar system - and are commonly known as ice giants. Swiss researchers have calculated that this picture may not be correct.
14.12.2025, 23:13
dpa
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- Uranus and Neptune are around four times the size of Earth and are considered the two ice giants of our solar system.
- According to new calculations by the University of Zurich, however, they could be rocky rather than icy.
- However, further studies are needed to gain more certainty.
Uranus and Neptune are around four times the size of Earth and are considered the two ice giants of our solar system - alongside the rocky planets Mercury, Venus, Earth and Mars, as well as the two gas giants Jupiter and Saturn. According to new calculations, however, they could be rocky rather than icy, as reported by the University of Zurich (UZH).
The two planets at the edge of our solar system have so far been poorly understood, said Luca Morf, lead author of the study. His team has now combined common physical and empirical models. Ravit Helled, Professor at the Institute of Astrophysics, said that it had already been assumed 15 years ago that the planets were not only made of ice. "Now we finally have computational proof."
Both outer planets could therefore be rocky worlds with a thick icy shell - but this is not certain. Physicists do not yet have a good understanding of how materials behave under the pressure and temperature conditions inside the planets. Further studies are therefore needed to gain more certainty. This may only be possible with missions to Uranus and Neptune, said Helled.
The planetary sequence and the mnemonic
To remember the order of the planets, there is the mnemonic "My father explains our night sky to me every Sunday". Each letter stands for a planet, viewed from the sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The phrase used to be: "My father explains our nine planets to me every Sunday." After more and more celestial bodies were discovered that resemble Pluto, it was downgraded to a dwarf planet in 2006 and no longer counted.