Eyewitnesses say that Joseph Smith and other LDS leaders not only described inhabitants on the moon, but also prophesied that 18th and 19th century Mormons would do missionary work there.
Here are some sources for that information: (courtesy of Steve Benson)
1. Will Schmidt, “Joseph Smith, Brigham Young and Extraterrestrial Quakers!,” in “The Watchman Expositor,” vol. 6, no. 9, 1989
2. Jerald and Sandra Tanner, “The Changing World of Mormonism,” Chapter 1, “A Marvelous Work?” (Chicago, Illinois: Moody Press, 1981), pp. 23-25
3. James B. Allen, “But Dick Tracy Landed On The Moon,” in “Sunstone,” vol. 7, no. 5, issue #35, September/October 1982, pp. 19-20
4. Van Hale, “Mormons and Moonmen,” in ibid., pp. 13–17
5. “Moonmen and the Mormons,” from the newsgroup alt.religion.mormon
6. Bill McKeever and Aaron Shafovaloff, “Early Mormon Leaders on the Inhabitants of the Sun and Moon: Did Joseph Smith Teach That the Moon was Inhabited by People Dressed Like Quakers?; Philo Dibble's Account of Joseph Smith,”
For more information, see The Mormon Mirage 3rd Edition: A Former Member Looks at the Mormon Church Today(Zondervan, 2009). Also available as an audiobook and as an expanded-text E-book for Nook, Kindle and other reading devices.