Abstract:  With thousands of exoplanets already discovered, we have begun to assemble and identify the best and brightest targets for atmospheric characterization. Compared to the bodies of the Solar system, studies of exoplanets will be limited to interpreting their hemispherically averaged properties. Direct observation of the disk-integrated brightnesses of bodies in the Solar System, and their variations with illumination angle, wavelength, and planetary longitude, is essential for both planning imaging observations of exoplanets and interpreting the eventual datasets. I will present my analysis of Cassini Imaging Science Subsystem data of the Galilean satellites as analogs for icy terrestrial worlds and discuss how we can use their reflected light curves and exploit their surface inhomogeneities to deduce surface variations, determine rotation periods, and reconstruct spatially resolved maps of icy terrestrial worlds. The diversity of exoplanets is not represented by the bodies in our Solar system: I will present a series of one-dimensional atmospheric simulations to assess our ability to characterize these disparate worlds with present instrumentation, such as TESS and HST, as well as future observatories, notably JWST. I will further discuss how Juno and Cassini data will continue to inform plans for future exoplanet observations, and what more spacecraft studies of the Solar System and developments in spectroscopic modeling have to offer in contextualizing exoplanet observations.

Host:  Dan Stevens