( in full the Search for Extra-Terrestrial Intelligence )
a US organization set up in 1984 to conduct research into whether life exists outside the Earth. It is a private, non-profit organization but often government organizations such as NASA give financial support to some of its projects. It consists of two parts: the Center for SETI , which searches for signals from space, and the Center for the Study of Life in the Universe , which researches how life began in the universe and how it may have developed.