Since the fall of 1997, NASA satellites have continuously observed all plant life at the surface of the land and ocean. This view of life from space is furthering knowledge of our home planet, and how it's changing In the Northern Hemisphere, ecosystems wake in the spring, taking in carbon dioxide and exhaling oxygen as they sprout leaves – and a fleet of Earth-observing satellites track the spread of vegetation. Meanwhile, in the ocean, microscopic plants drift through sunlit surface waters blo