Surface Compositions Across Pluto and Charon

TL;DR

This study uses New Horizons data to analyze the surface compositions of Pluto and Charon, revealing complex volatile ice distributions, regional color diversity, and localized ammonia-rich areas.

Contribution

It provides detailed mapping of surface ices and colors on Pluto and Charon, highlighting spatial variations and new insights into surface processes.

Findings

Pluto's surface has complex distributions of CH4, CO, and N2 ices.

Pluto's water ice bedrock is mapped with isolated outcrops.

Localized NH3 absorption is found near fresh impact craters on Charon.

Abstract

The New Horizons spacecraft mapped colors and infrared spectra across the encounter hemispheres of Pluto and Charon. The volatile ices CH$_4$, CO, and N$_2$, that dominate Pluto's surface, have complicated spatial distributions resulting from sublimation, condensation, and glacial flow acting over seasonal and geological timescales. Pluto's H$_2$O 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 NH$_3$ absorption tied to small craters with relatively fresh-appearing impact ejecta.