In 2008, NASA’s Lander Phoenix touched down in the north region of Mars. Loaded with an array of instruments, it made several discoveries that changed our view of Mars’ geochemistry and potential for life. The results then provoked a reanalysis of Antarctic soils, leading to the discovery of a continent-wide and global presence of perchlorate on Earth, with eventual implications at the politically charged level of environmental and drinking water controls. Over the past 40 years, observations from spacecraft orbiting or landing on planets and moons have provided new knowledge from neighbors near and far: Mars, Venus, Mercury, Titan, and Europa, among others. They have given us views of worlds that are at the same time very familiar and yet alien. They have provided us with windows into eras long erased on Earth but at the core of our emerging existence. They have given us premonitions of a future Earth heating out of control or of a possibly frozen past. We have found the solvent of life in almost every corner we have looked, from liquid global oceans to frozen ice caps to slivers in shaded crevices. Most of all, because every place on Earth there is water there is life, from the clouds to kilometers below the surface, we have yet to exhaust the quest for other places where kindred life my hide. Our search, however, has told us more about us than ever imaginable. To paraphrase T.S. Eliot, at the end of our exploring, we will arrive where we started and know the place for the first time.