Although our planet feels indescribably large, in the context of the universe it is infinitesimally small. For some, the feeling of smallness associated with being reminded of the vastness of the universe might represent a psychological threat. For others, it could be a self-transcendent experience, helping them rise above self-focused concerns and to feel a sense of oneness with others. In two studies (Ns = 294 and 409) we exposed people to videos that did or did not depict the enormity of the universe. Compared to a control condition, low self-esteem people exposed to the vastness of the universe reported more negative affect, less identification with others, less empathy to victims of a humanitarian disaster, and lower egalitarianism. This effect was not found for high self-esteem respondents. Results are discussed with reference to research on awe and the small self.