Study links Uranus and Neptune's odd magnetic fields to deep conductivity shifts

By the Everything Space news desk · 06 Nov 2026 · written from the sources below

Image: Phys.org

Researchers say changing electrical conductivity inside the ice giants could explain their lopsided magnetic fields and predict they may shift significantly within decades.

Researchers led by a team at The University of Texas at Austin say variations in electrical conductivity deep within Uranus and Neptune may explain why the two planets have such chaotic, tilted magnetic fields, unlike Earth's orderly north-south arrangement.

When Voyager 2 flew past Uranus and Neptune in the 1980s, it found their magnetic fields were strangely disordered. Earth's magnetic dipole is tilted only about 11 degrees from its rotational axis, but Uranus' dipole is tilted 59 degrees and Neptune's 47 degrees.

Magnetic fields arise from dynamos, the movement of electrically conducting fluid inside a planet. On Earth, that fluid is molten iron in the outer core. The composition of Uranus and Neptune is less certain, but scientists believe the ice giants are made largely of hydrogen, helium, water, ammonia, methane and rock.

The new study, published in Communications Physics, proposes that extreme pressure and temperature deep inside these planets could break apart water molecules into ions, making the material more electrically conductive at greater depths. Computer simulations incorporating this conductivity pattern were able to reproduce magnetic fields resembling those seen by Voyager 2.

The simulations also suggest the ice giants' magnetic fields could change dramatically over just decades, in sharp contrast to Earth, whose magnetic tilt drifts only slightly over a half-century. According to the researchers, some simulated scenarios showed the tilt swinging by tens of degrees within a matter of decades, while others showed only minor shifts over similar periods.

Scientists are now studying infrared images from the James Webb Space Telescope showing auroral activity on Uranus and Neptune, hoping that patterns in these emissions can reveal whether the planets' magnetic dipoles have already shifted since the Voyager 2 flybys.

The team plans to combine the Webb auroral data, the original Voyager 2 measurements and their dynamo simulations to estimate the current state of the ice giants' magnetic fields, though they note that future missions to Uranus and Neptune would be needed to better understand their interiors.

Written in Everything Space’s own words by our news-desk model from the sources above, and checked against them in code: every number in this report appears in its sources, and no sentence is copied from them.