5/23/25

Roughly 3.8 million years after the solar system’s first solids formed—a key moment when the disk of material around the Sun, known as the protoplanetary nebula, was dissipating—Jupiter was significantly larger and had an even more powerful magnetic field.](https://www.caltech.edu/about/news/jupiter-was-formerly-twice-its-current-size-and-had-a-much-stronger-magnetic-field)