Researchers Propose 5,300-Km Ganymede Built Its Magnetic Field Through Late Core Heating
Updated
Updated · Livescience.com · May 25
Researchers Propose 5,300-Km Ganymede Built Its Magnetic Field Through Late Core Heating
1 articles · Updated · Livescience.com · May 25
A new Science Advances study says Ganymede’s magnetic field may have formed late, with molten iron-rich blobs still sinking toward the moon’s core instead of a dynamo starting soon after birth.
The model argues the 5,300-km moon could have begun too cold for early core formation, then warmed enough through radioactive decay and Jupiter-driven tidal flexing to build and stir a conductive core over time.
That “warming-driven dynamo” challenges the standard picture in which magnetic cores form within roughly 200 million years of the solar system’s birth and then gradually cool.
Because magnetic fields help shield worlds from harmful radiation, the mechanism could widen the range of planets and moons—including some exoplanets—that might sustain protective magnetospheres later in their histories.
Could late-blooming magnetic shields on 'dead' worlds create new havens for life?
If Ganymede’s core formed 'backwards,' what else is wrong with our theory of planetary birth?