This talk will focus on the information to be gained through UV reflectance spectroscopy of atmospheres in the outer solar system. Here, we are concerned with the spectral region below 3000 Å, where many interesting molecular species have significant absorption cross sections, and observations must be made from sounding rockets or space-based observatories. With the exception of a few important rocket measurements the bulk of the observations in this region to dat have been made with the Voyager spacecraft and IUE observatories. The Voyager Ultraviolet Spectrometer (UVS) measurements offer the advantage of relatively high spatial resolution while IUE permits repeated measurements over a long time base. HST will combine both features and should led to a significant advancement in our understanding of outer solar system atmospheres.