This article compares justifications of the search for extraterrestrial intelligence (SETI) presented by scientists with ideational constructs associated with cargo cults in Melanesia. In focusing on similarities between cargoism and SETI, I argue that, understood in terms of cultural practice, aspects of the science of SETI have significant similarities to the religious elements that characterize cargoism. Through a focus on the construction of meanings, I consider how SETI and cargoism use similar signification systems to communicate meaning related (...) to local social contexts and I draw a parallel with the religious and meaning structure of cargoism to show that SETI and cargoism employ similar strategies to justify beliefs. As a result, in some ways SETI represents a scientific framework that inhabits cultural and epistemological space that overlaps with religious space. (shrink)