Abstract
The characterization of the atmospheres of terrestrial ("rocky") planets, long the stuff of fantasy, is within our reach, starting in the next decade. The impact of the James Webb Space Telescope will be significant in this area, for the small but growing sample of planets orbiting the nearest lowest-mass M stars. I will highlight a project to assess how precise radial velocity planet masses must be to yield robust atmospheric constraints. However, it seems that "comparative atmospheric planetary science" with a large sample size may have to wait til at least the late 2030s or beyond, with future space telescopes. I will discuss work to quantify the requirements for wavelength coverage, spectral resolution, and signal-to-noise needed for future optical reflected light telescopes like LUVOIR or HabEx, which aim to characterize terrestrial planet atmospheres. Finally, I will show new experimental work, in collaboration with colleagues at UC Santa Cruz, to investigate the origins of terrestrial planetary atmospheres, via studies of meteorite outgassing. Such studies are one part of a long network of not yet well-understood physical and chemical processes that dictate atmospheric origin and evolution, which must be studied in tandem with new exoplanet observations.