The trivia is buried in this article, so that those not interested in the main topic the trivia is:
Many of the Jupiter's Galilean moons are attractive targets for terraforming due to their high abundance of water, but only Callisto lies far enough away from the radiation belts generated by Jupiter's magnetosphere. On Earth, we're exposed to about 0.066 rems of radiation per day. In contrast, Ganymede receives 8 rems of radiation per day, Europa receives 540 rems per day, and Io receives a whopping 3,600 rems. Callisto, in contrast, is exposed to about 0.01 rems per day, which humans can tolerate.
Top 4 candidates in our solar system for terraforminghttps://bigthink.com/surprising-science/terraforming-solar-system?rebelltitem=4#rebelltitem4
