ABSTRACT
The search for extraterrestrial intelligence, or Search for Extraterrestrial Intelligence (SETI), has existed as a discipline since Cocconi and Morrison published a rationale for a search for narrow-band radio transmission from nearby stars. SETI endeavors have expanded in number of targets, sky coverage, and spectral coverage. It is important to distinguish SETI from messaging ETI (METI). Also known as active SETI, METI involves beaming transmissions toward nearby stars thought likely to permit the evolution of life. Some of the difficulties involved in optical and IR SETI are the opacities of the media through which the radiation propagates. One of the biggest missing links in the electromagnetic spectrum for SETI are the bands to which the Earth’s atmosphere is opaque. While it is cost-prohibitive to place a telescope in space for the purpose of SETI, evidence of ETI might be hiding in the data of existing space telescopes.
