Introduction to Comparative Planetology presents an intertwined analysis of visual cultures of imagining the Earth and geopolitics of climate emergency. It compares different "figures" of the planet - the Planetary, the Globe, the Terrestrial, Earth-without-us and Spectral Earth - in order to assess their geopolitical implications. These implications are then mapped on respective prospects of these figures in developing an infrastructural space for planetary coordination of our design interventions against runaway global heating, and ultimately against mass species extinction.