Farmer In The Sky is a 1950 science fiction novel by American writer Robert A. Heinlein about a teenaged boy who emigrates with his family to Jupiter's moon Ganymede, which is in the process of being terraformed.

Among Heinlein's juveniles, a condensed version of the novel was published in serial form in Boys' Life magazine (August, September, October, November 1950), under the title "Satellite Scout".

[1] Passing references by the lead character to the song "The Green Hills of Earth" and to its author, Rhysling, have caused some to consider it part of Heinlein's Future History series.

The soil has to be built from scratch by pulverizing boulders and lava flows, then seeding the resulting dust with carefully formulated organic material, and the rock crushers are in short supply.

While some whine about the injustice of it all, Bill accepts an invitation to live with his prospective neighbors, a prosperous farmer and his large, hard-working family, to learn the needed skills, while his father signs on as an engineer in the town of Leda.

While exploring, he and his friend Hank discover artifacts of an alien civilization, including a working land vehicle that has legs, like a large metal centipede.

Groff Conklin wrote that although Farmer in the Sky was "conceived as a novel for 'adolescents' ... this book is also one of the best of the month's output in science fiction for adults ... an adventure story with an unusual amount of realism in its telling.

[2] Boucher and McComas named Farmer "just about the only mature science fiction novel of the year [1950]", describing it as "a magnificently detailed study of the technological and human problems of interplanetary colonization.

This effect could be achieved in reality by releasing large quantities of super greenhouse gases, which would not require a constant power supply, and would therefore be unaffected by a disaster such as that described in the book.

The Galileo flyby in 1995 discovered that Ganymede has a magnetosphere, but the shielding effect is weak; it is believed that the surface radiation intensity would still be lethal within months.