In recent years the concept of planetarity has seen a meteoric rise among critical theorists. But they often leave its exact signi cance opaque or even actively obscure the meaning of ‘planet’. Can space history unearth a more accurate conceptualization by de-metaphorizing planetarity and fostering a spatial understanding of planet Earth instead? In this roundtable, a philosopher, a media theorist, a cultural historian, a historian of technology and a religious studies scholar discuss the uses of planetarity in their respective disciplines. They ask what all that planetarity talk is about, if proclaiming a planetary turn can be justified, and whether understanding the transformation of Earth into a planet over the course of the twentieth century necessitates an extra-terrestrial perspective.