![magnetic fieldlines in earth iron cor magnetic fieldlines in earth iron cor](https://1.bp.blogspot.com/_sQBXvZLKGMo/TMxGxYW-YgI/AAAAAAAAACc/NZqKZNl-MmY/s320/6.jpg)
In contrast, internal sources include remanent magnetization in crustal rocks on Mars, Earth, and the Moon or self-sustaining dynamos in the deep interiors of planets. For example, external sources that generate observed planetary magnetic fields include Venus' ionospheric currents, Earth's magnetospheric currents, and electromagnetic induction in the saltwater oceans of Europa, Ganymede, and Callisto due to Jupiter's time varying field. Observed planetary magnetic fields can result from a variety of processes.
![magnetic fieldlines in earth iron cor magnetic fieldlines in earth iron cor](http://web.pdx.edu/~ruzickaa/meteorites/Weisberg/differentiation.jpg)
įield characterized by weak dipole moment, large dipole offset, and small dipole tilt.Detection of dynamo-generated magnetic field