An aspect of John Herschel’s science not widely appreciated was his complex view of Earth as a planet and as our entry point for understanding physical and chemical processes everywhere in the universe. Herschel was a crucial and consistent voice in bringing both the astronomy and physics of Newton and the most recent chemistry to bear on the Earth. In this chapter, I provide a view of Herschel’s evolving interest in the Earth and in geology. I present his interaction with the Earth sciences as a unifying thread running through his life, pulling together aspects of his work that otherwise may seem disparate activities. I examine Herschel’s formation as a geologist and a scientific traveler. Lastly, I discuss some of the ways that Herschel’s background in physics, chemistry, and astronomy affected his understanding of geology. Herschel sought to understand the cosmos both by looking up at the stars and down at the Earth.