The Climate and Habitability of Short-Period Planets

Abstract: In recent years planet hunters have discovered thousands of exoplanets (planets orbiting other stars).  We now know that most temperate terrestrial planets orbit close to dim red stars and experience dramatically different stellar forcing than the Earth, notably permanent day and night hemispheres.  Since we have no analogs to these worlds in our Solar System, we must observe them to understand their atmospheric composition, clouds, and wind patterns. To date, we have been able to study the climates of a few dozen exoplanets, all of which are far too hot to be habitable. Cutting-edge analysis techniques and next-generation instruments should allow us to extend our methods to temperate terrestrial planets orbiting nearby red dwarfs.  In the coming decade, we will be able to determine which of these planets are, in fact, habitable and we will start to search them for signs of life.