This episode explores the field of astrogeology, explaining how scientists use the principles of Earth’s geology to study planets, moons, asteroids, and other solid bodies across the solar system. The hosts discuss key questions about planetary formation, impact craters, volcanic activity, water evidence, and rock composition, highlighting how these clues reveal the history of other worlds and our own. They also introduce pioneers like Eugene Shoemaker and connect the science to local training sites in the American Southwest, while explaining how tools like spectroscopy allow scientists to study distant planets through light.