I remember, as a young boy, watching the night sky to see the first artifical satellite call "Sputnik" in 1957. Our world and our ability to observe our world has changed tremendously in since that small object was launched into orbit around the earth. Here is a wonderful, beautiful video from NASA that takes us on a journey above our home. Earth observations from satellites have made incredible advances in the 56 years since I saw the first satellite. Enjoy.