Magnetic Field Mystery Solved?

OneOver137 writes "Researchers at Harvard may have solved a long-standing mystery: Why are the magnetic fields of the outer gas giants, Uranus and Neptune so unique? Further more, could these fields be used to probe the internal structure of other planets like Mercury, a notoriously difficult subject? Maybe this new technique could be used on the Messenger mission?"

Comments

Is there enough sample points?

[Eevee]

The short blurb on PhysicsWeb said the measurements were all made by Voyager 2. A single pass is, while better than nothing, a rather limited snapsnot of a dynamic system.

Sounds like we need a Voyager 3 and 4 the next time there's a decent slingshot out to them. (Which isn't any time soon.)

Re:Is there enough sample points?

[tjmsquared]

The NASA trend lately has been to send probes to study just one planet rather than do the solar system tour that we did with Voyager. Since we've already sent such missions to Jupiter and Saturn, maybe Uranus and Neptune are next.

Further field splits with cooling?

[G4from128k]

If these two outer gas giants cool further, I wonder if the convecting fluid layer will become thinner and thinner as the core freezes? If so, the magnetic field should split into more and more domains. Ultimately, the remaining thin layer will form a dense pattern of Rayleigh-Benard convection cells.

Those small domains will be hard to detect, though. As planet moves to equilibrium and the fluid layer thins and cools, the delta-T driving the convention will weaken. Smaller cells of slower-moving fluid will mean a much weaker magnetic field. Now we only need to wait a few billion years to see if this is what will happen......