This graphic compares the magnetic fields of Earth and Jupiter, characterizing the field on the surface of each planet in terms of spatial scale, with large scale to the left, and small scale to the right. The linear progression of terms characterizing Earth's field identifies a dynamo core radius at 0.54 planet radius and crustal magnetization at smaller scales. By analogy, the new Jupiter model identifies a dynamo core radius at 0.81 planet radius, in the convective metallic hydrogen just beneath a zone stabilized by helium rain.

More information about Juno is at https://www.nasa.gov/juno and https://missionjuno.swri.edu.