Jupiter also has a magnetic field, but it is truly enormous, by far the largest in the Solar System. Without knowing what its innards are doing, however, how it produces such a colossus remained highly speculative.
Thanks to Juno’s ability to probe internal gravity changes as things move about, however, we now have, for the first time, a working observational model of the gas giant’s own dynamo. It’s safe to say that it surprised those looking through the data, and other researchers who’ve spent much of their careers trying to guess what it may be like.
“We’re finding that Jupiter’s magnetic field is unlike anything previously imagined,” the mission’s deputy-principal investigator, Jack Connerney of the Space Research Corporation, said in a statement.
Instead of being a “simple” bar magnet model that more or less applies to our own world, it turns out that Jupiter’s is both messy and far more complex.
Between the north pole and the equator, for example, an intense spot of positive magnetic field is surrounded by areas that are far weaker and negative. The south pole, however, is intensely negative, and it progressively weakens as you get nearer to the equator.
So – what’s causing this anomalous behavior? At present, rather marvelously, no-one’s quite sure, although it’s indubitably something happening deep below that we’ve yet to see in its still-enigmatic interior.
Hopefully, Juno’s additional orbits will take us some way toward solving this increasingly bemusing dilemma.