From Hot Neptunes to Temperate Earths: Observing the Atmospheres of Small Planets

Substantial resources have been dedicated to characterizing the handful of planets with radii between Earth’s and Neptune’s that are accessible to current telescopes. Observations of their transmission spectra reveal a diversity of worlds, some shrouded in clouds and others with molecular features. I will discuss the types of clouds and hazes that can obscure transmission spectra, and show the effect that these thick clouds have on the thermal emission and reflected light spectra of small exoplanets. I present a path forward for understanding this class of planets: by understanding the thermal emission and reflectivity of small planets, we can potentially break the degeneracies and better constrain the atmospheric compositions. With future telescopes, we will also be able to access even smaller, more temperate worlds. I will discuss the recent discoveries of Earth-sized planets around small bright M dwarfs. These atmospheres may have atmospheres observable with JWST; I will explain how we might detect those terrestrial atmospheres in the coming years.

Speaker: Caroline Morley, CfA