There is a tendency to regard SETI as a space-age activity. In fact, as we have seen, belief in, and the search for, extraterrestrial beings stretch back into antiquity. Today a separation is usually made between belief in extraterrestrial life forms and belief in supernatural or religious entities -- i. e., between aliens and angels. Yet it was not always thus. For most of human history the "heavens" were literally that: the domain of the gods. Beings who inhabited the realm beyond the Earth were normally regarded as supernatural.
In spite of the fact that ET is now firmly in the domain of science, or at least science fiction, the religious dimension of SETI still lies just beneath the surface. Many people draw comfort from the belief that advanced beings in the sky are watching over us and may some day intervene in our affairs to save us from human folly.