THE PLUTO SYSTEM

Pluto, its large satellite Charon, and its two small satellites Nix and Hydra, represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique, lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Currently our understanding of the Pluto system is limited to their orbital characteristics, bulk geophysical properties (i.e., size and density), and atmospheric and surface characteristics (e.g., albedo and surface composition). Modeling of the interior suggests that geologic activity may have been significant to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. These putative indicators of Pluto's geologic history are inconclusive and unspecific, however. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observation. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system’s geologic history.