Family groups comprise a significant percentage of the museum visitor population, and many programs are created specifically for young learners (Borun, 2008). One such learning environment is that of planetaria, where both live and pre-recorded programs are presented to introduce concepts in Earth and Space Science to young children. Pacific Science Center's Preschool Trip to the Moon live, interactive planetarium program was used as a context for exploring families' motivations for attending a planetarium show, their reactions to the show, and in particular what children learned from the show. Methods included adult questionnaires and child interviews. Adult motivation for attending the program was largely due to their own interest in astronomy or their desire for their child to be interested in astronomy, not because the child was already interested in the subject. Children expressed an interest in returning to the planetarium in the future, and many identified several features of the program that they enjoyed. Results pertaining to what children learned suggested a range of outcomes that were behavioral, observational, and conceptual. Future planetarium programming should incorporate support for adults in rooting this interest through informal education led by the adult.