Uranus has a weird magnetic field that's stumped scientists for 40 years — we may finally know why
The solution to the weird magnetic fields of the solar system's ice giants may come down to how planets generate their magnetic field through the dynamo effect.
Key points
- Inside Earth, the electrically conducting fluid is the molten iron in the outer part of our planet’s core, and the magnetic field that it generates has clear north and south poles – what we call a dipole, a phenomenon that we can also see in the two magnetic poles of a simple bar magnet.
- If we compare these planets to Earth, which has a stable magnetic field tilted by just 11 degrees to our planet’s rotation, we can see how extreme the magnetic fields of the ice giants are.
- The posided magnetic fields of Uranus and Neptune may stem from extreme conditions lying within their deep interior.
Uranus’ magnetic field was offset from its rotational axis by 59 degrees and isn’t even centered on the planet’s core, but instead is only two-thirds of the way down.
Uranus as a whole is tilted by 97 degrees and effectively rolls around the sun, and speculation is that billions of years ago it was knocked on its side by a collision with a long-lost Earth-sized planet.
Additional details
- This arises from the swirling, convective motion of an electrically conducting liquid within a rotating body, which is able to generate and maintain a powerful magnetic field.
- This showed how the magnetic-field structure co-evolves alongside changes in the fluid motion driven by convection and the temperature inside the planets.
- Neptune is similar, with a disordered magnetic field offset by 47 degrees and centered halfway between the core and its visible cloud tops.
- and the UK, based on computer simulations and Voyager 2’s measurements of the two planets’ magnetic fields, may have found a solution.
- This might be a plausible explanation were Neptune’s magnetic field also not similarly skewed without having experienced a collision.
How this summary was made: extractive summary — built from the sources' own reporting. It is drawn only from the reporting of the sources listed below — read the originals for full detail. How we summarize →
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