Everyone knows that NASA studies space; fewer people know that NASA also studies Earth. Since the agency’s creation almost 50 years ago, NASA has been a world leader in space-based studies of our home planet. Our mission has always been to explore, to discover, and to understand the world in which we live from the unique vantage point of space, and to share our newly gained perspectives with the public. That spirit of sharing remains true today as NASA operates 18 of the most advanced Earth-observing satellites ever built, helping scientists make some of the most detailed observations ever made of our world.