SIM Lite would have been the most powerful extrasolar planet hunting space telescope ever built. Through the technique of interferometry the spacecraft would be able to detect Earth-sized planets. SIM Lite was to perform its search for nearby, Earth-like planets by looking for the "wobble" in the parent star's apparent motion as the planet orbits. The spacecraft would have accomplished this task to an accuracy of one millionth of an arcsecond, or the thickness of a nickel viewed at the distance from Earth to the Moon. Titled the Deep Search, the planet hunting program was intended to search approximately 60 nearby stars for terrestrial planets (like Earth and Venus) in the habitable zone (where liquid water can exist throughout a full revolution (one "year") of the planet around its star). The Deep Search was to be the most demanding in terms of astrometric accuracy, hence the name, Deep Search. This program would have used the full capability of the SIM Lite spacecraft to make its measurements.