"Published posthumously, it is a short story about a dream of life on the moon. There is no mathematical content in the actual story, but Kepler included voluminous notes, plus a selenographical appendix, to go with the story, much of it explicit (if elementary) astronomical calculations."

"Edward Rosen's translation (KEPLER'S SOMNIUM: THE DREAM OR POSTHUMOUS WORK ON LUNAR ASTRONOMY, University of Wisconsin Press, 1967) includes Kepler's notes, along with his own extensive commentary and battery of appendices."

"Self-reference freaks will appreciate Kepler's footnote 5, attached to the narrator's statement that his mother (the witch whose occult powers got him to the moon, and thus not to be trifled with) does not approve of him writing. There is no footnote 5."