Since 1998 the Earthshine Project has been a collaborative effort between Big Bear Solar Observatory/New Jersey Institute of Technology and California Institute of Technology. Cyclic spectroscopic observations of the dark and bright sides of the moon (or earthshine and moonshine, respectively) have been carried out in the visible region at Palomar Observatory. From these data, the ratio of the earthshine to moonshine characterizes the globally averaged Earth's spectrum. Information concerning the search for extra-solar, terrestrial planets can be also obtained from these observations.