Abstract
With recent developments in direct imaging spectroscopy, the exoplanet community will soon have access to the spectra of hundreds, or even thousands, of extrasolar gas giants and brown dwarfs. However, as point-source spectra, there will be no spatially resolved context for these observations. In this thesis, I discuss using Jupiter and Saturn, our only spatially resolvable counterparts to extrasolar gas giants and brown dwarfs, as spectral analogs. In Chapter 1, I provide a brief historical context for this thesis and discuss its motivation and impact. In Chapter 2, I present point-source spectra of Jupiter and Saturn for a variety of phase angles, as well as provide end member, or single-feature spectra, for permutations of illumination and cloud density. Here, I also briefly touch on using spectral variations as a means to detect rings around exoplanets. Finally, in Chapter 3, I discuss future projects that are extensions of the work presented in this thesis.