The search for extraterrestrial intelligence (SETI)

The search for evidence of extraterrestrial intelligence is placed in the b roader astronomical context of the search for extrasolar planets and biomar kers of primitive life elsewhere in the universe. A decision tree of possib le search strategies is presented as well as a brief history of the search for extraterrestrial intelligence (SETI) projects since 1960. The character istics of 14 SETI projects currently operating on telescopes are discussed and compared using one of many possible figures of merit. Plans for SETI se arches in the immediate and more distant future are outlined. Plans for suc cess, the significance of null results, and some opinions on deliberate tra nsmission of signals (as well as listening) are also included. SETI results to date are negative, but in reality, not much searching has yet been done .