Abstract:
Our Solar System contains only a few examples of planets with atmospheres. Although astronomers have gathered decades of beautiful data from these worlds, the limited environments represented in our local planetary system restrict the questions we can ask about how atmospheres work. Yet, billions of exoplanets orbit stars in the Milky Way, thousands have been discovered by Earth-bound astronomers, and hundreds have atmospheres within observational reach of current telescopes. These new planets enable new questions. How much smaller could Neptune be before it loses its thick hydrogen/helium atmosphere? Could Mercury retain a carbon dioxide atmosphere if it were just a little bigger? What happens to frigid Saturn's atmosphere if we heat it to the temperature of a ceramic kiln? Is Earth's atmosphere the only one sculpted by life? In this talk, I will describe how we study exoplanet atmospheres through the color of their sunsets and the glow from their surfaces, what these enigmatic worlds are teaching us about atmospheric processes, why starspots are annoying and what we plan to do about them, and how generations of CU students can contribute to a deeper understanding of how planetary atmospheres work and ultimately to the search for life beyond Earth.