Modeling Pluto's light curve in the near infrared : implications for observation post new horizons

Abstract

The effects of volatile transport on Pluto's surface on ground-based observations of Pluto's light curve were studied. Due to Pluto's eccentricity of 0.249, obliquity of 123 degrees, and atmosphere, the transfer of volatiles may cause global surface change over the course of Pluto's orbit. Magellan visible and near infrared data were gathered one month before the New Horizons flyby in order to compare ground-based observing with spacecraft data. Furthermore, a model was created in order to predict how volatile transport will affect ground-based observations in the future. The near-infrared data show large scale surface composition as a function of longitude and confirm New Horizons' compositional results. The model determines that the composition of the underlying layer on Pluto's north pole can be determined by monitoring the J - Ks ratio, if the nitrogen ice currently located on the north pole is sublimated due to volatile transport. Therefore, ground based observing can monitor volatile transport and global surface changes can be monitored after the New Horizon's flyby.