A new paper by Alternative Earths Co-I Jun Korenaga, "Can mantle convection be self-regulated?" was published this month in "Science Advances." Research suggests that simply being in the habitable zone isn’t sufficient to support life. For decades, it was thought that planets are able to self-regulate their internal temperature via mantle convection. A planet might start out too cold or too hot, but it would eventually settle into the right temperature. Now, Korenaga presents a general theoretical framework that says a planet also must start with an internal temperature that is just right. He explains the degree of self-regulation expected for mantle convection and suggests that self-regulation is unlikely for Earth-like planets, implying that chance factors in planetary formation are even more important for the evolution of planets that are more massive than Earth.