Since the discovery of the first planet outside the solar system, the number of planet detections is increasing exponentially. Although we have not been capable of detecting and exploring planets like our own yet, challenging space missions are already being planned for the next decades, and the discovery of earth-like planets is only a matter of time. When the time arrives, one of our main concerns will be to determine their degree of similarity with our own planet, and to answer a more intriguing question for the humankind: if there is life on them. An indication of complex life is the vegetation's red edge. Using real cloud cover observations from satellite, we have unequivocally detected the vegetation's signature in the Earth's globally averaged spectrum. The signature is stronger when large vegetated regions of the Earth are seen free of clouds. Our results show that, considering the real cloud cover present in our planet, previous estimates of the vegetation signal strength were over-optimistic.