Kepler’s Somnium circulated in manuscript form after 1611, but it remained unpublished until after his death in 1630. Kepler’s first manuscript contained only the basic tale of his hero’s voyage to the moon; Kepler later expanded the work with a series of detailed footnotes explaining the nature of the lunar environment and the creatures he supposed lived there. In time, the footnotes grew to outnumber the original story by roughly four pages to one.

Kepler hoped to publish the works and footnotes along with two classical stories that describe fictional visits to the moon: Kepler’s own translation of Plutarch’s “On the Face in the Moon”, from the 2nd Century, and the satirical “True History” by Lucian of Samosata, written in the 1st Century. Kepler’s Somnium was finally published by his family in 1638, but without the stories by Plutarch and Lucian.

Kepler crater on the moon

Kepler crater on the moon.