The New Horizons spacecraft mapped colors and infrared spectra across the encounter hemispheres of Pluto and Charon. The volatile ices CH4, CO, and N2, that dominate Pluto's surface, have complicated spatial distributions resulting from sublimation, condensation, and glacial flow acting over seasonal and geological timescales. Pluto's H2O ice "bedrock" is also mapped, with isolated outcrops occurring in a variety of settings. Pluto's surface exhibits complex regional color diversity associated with its distinct provinces. Charon's color pattern is simpler, dominated by neutral low latitudes and a reddish northern polar region. Charon near infrared spectra reveal highly localized areas with strong NH3 absorption tied to small craters with relatively fresh-appearing impact ejecta.
@article{arxiv.1604.05368,
title = {Surface Compositions Across Pluto and Charon},
author = {W. M. Grundy and R. P. Binzel and B. J. Buratti and J. C. Cook and D. P. Cruikshank and C. M. Dalle Ore and A. M. Earle and K. Ennico and C. J. A. Howett and A. W. Lunsford and C. B. Olkin and A. H. Parker and S. Philippe and S. Protopapa and E. Quirico and D. C. Reuter and B. Schmitt and K. N. Singer and A. J. Verbiscer and R. A. Beyer and M. W. Buie and A. F. Cheng and D. E. Jennings and I. R. Linscott and J. Wm. Parker and P. M. Schenk and J. R. Spencer and J. A. Stansberry and S. A. Stern and H. B. Throop and C. C. C. Tsang and H. A. Weaver and G. E. Weigle and L. A. Young and the New Horizons Science Team},
journal= {arXiv preprint arXiv:1604.05368},
year = {2016}
}