Astronaut Alexander Gerst was quoted as saying “It is crystal clear from up here that everything is finite on this little blue marble in a black space, and there is no planet B.” That little blue marble floating in space is the key to us understanding the potential for life elsewhere in the universe. We also have the tremendous capability and responsibility to focus our eyes in the skies downward to understand, predict and manage how life on our planet is changing. This talk will consider how NASA Earth Science and its partners are conceptualizing, building, launching and operating critical assets in space to understand our changing planet and how we use that understanding to advance knowledge of Earth as an integrated system. It will also uncover some of the ways we learn about other planets by looking at our own. Fundamentally, if we can better connect to the pursuit to understanding our fragile blue planet, we can be informed stewards of it for the future.