Oliver Huntington records Joseph taught that the moon was inhabited.
Oliver B. Huntington, Journal, ca. January–February 1881, Book 14, 94, L. Tom Perry Special Collections, Harold B. Lee Library, Brigham Young University
"Inhabitants of the Moon are more of a uniform size than the inhabitants of the Earth, being about 6 feet in height. They dress very much like the Quaker style & are quite general in style or the one fashion of dress.
They live to be very old; coming generally, near a thousand years."
This is the description of them as given by Joseph the Seer, and he could "See" whatever he asked the Father in the name of Jesus to see.