Compared to other NASA programs, the Discovery missions have A. been very disappointing. B. had several highly publicized disasters. C. made new discoveries for relatively little cost. D. allowed astronauts to travel to more places in the solar system. What does the Drake equation tell us? Drake equation: N = R* × ƒp × ne × ƒl × ƒi × ƒc × L A. the exact number of extraterrestrial civilizations B. the rate of star formation and the chance that life will appear on any given planet C. an estimate for the approximate number of alien civilizations with which we could communicate D. the percentage of planets on which extraterrestrial life could emerge and send signals into space