Outpost of Jupiter

When his father's sudden illness stranded the Wilsons in the tiny human colony on Jupiter's moon, Bob gave up his plans for college and joined the colonists in their struggle against he brutal environment of Ganymede. The challenges, the comradeship he found, and the awe-inspiring spectacle of Jupiter filling the sky—all exhilarated Bob far beyond his expectations. So did his investigation of the major mystery behind the strange globe that was hidden out in the hills and that seemed to be trying to communicate with the colony. Before he could find the answer, a plauge struck and crippled the colony. Then enraged and fearful colonists accused Bob of being the carrier!