A compass on Uranus and Neptune

[Pluto the Snowman]

I always imagined that if you were to go to one of the solar systems ice giants, your compass would always point to the equivalent of Morocco or Hawaii............... But "always" may not be the case. Not only are the magnetic axis's (thanks spell checker, didnt have a clue on that one) not aligned to the planets rotation, but they also off-center. Therefore I am thinking that the entire magnetic axis is also moving around the center of the parent planets just like me, Muhammad Ali and Australia do around the core of the Earth. Just how would this affect a compass reading? I would imagine it would change like the weather if it were not revolving at the exact same rate as the surface of the planet.

 

Things that make me go "hmmmmmmmmmm". That one I came up with all on my own...

[acey]

As far as I'm aware, there isn't any significant shifting of the field on a daily basis on Uranus or Neptune due to their rotations. But their fields are a lot more complicated than Earth's, having large quadrupole as well as dipole moments, and large variations like a far bigger version of the anomalies detected on Earth. My guess is that a compass might be useful for short-distance navigation on one of those planets, but not for long distance. The axis of Uranus's dipole moment doesn't pass through the centre of the planet, but that in itself shouldn't be a problem - most of us don't use a compass in hope of navigating ourselves to the geographic north and south poles.

[digital_davem]

On 07/03/2016 at 00:00, Pluto the Snowman said:

I always imagined that if you were to go to one of the solar systems ice giants, your compass would always point to the equivalent of Morocco or Hawaii............... But "always" may not be the case. Not only are the magnetic axis's (thanks spell checker, didnt have a clue on that one) not aligned to the planets rotation, but they also off-center. Therefore I am thinking that the entire magnetic axis is also moving around the center of the parent planets just like me, Muhammad Ali and Australia do around the core of the Earth. Just how would this affect a compass reading? I would imagine it would change like the weather if it were not revolving at the exact same rate as the surface of the planet.

 

Things that make me go "hmmmmmmmmmm". That one I came up with all on my own...

On a practical note, even if we were somehow to be transported to these planets, they are not believed to have solid surfaces so there wouldn't really be anywhere worth navigating too ;-)