Europa Is Whistling. Finding The Cause May Solve A Magnetic Mystery

Jupiter’s moons “hum” — and researchers are trying to figure out why.New research published Tuesday in Nature Communications details the discovery of “whistler” radio waves coming from two of the moons: Ganymede and Europa. The other two large moons, Io and Callisto, aren’t subject to this phenomena.
The finding is interesting because both Europa and Ganymede — the largest moon in the solar system — have subsurface oceans.“Jupiter&rsquo