Composition and Surface Properties of Transneptunian Objects and Centaurs

Abstract

Centaurs and transneptunian objects are among the most primitive bodies of the solar system and investigation of their surface composition provides constraints on the evolution of our planetary system. An overview of the surface properties based on space- and ground-based observations is presented. These objects have surface showing a very wide range of colors and spectral reflectances. Some objects show no diagnostic spectral bands, while others have spectra showing signatures of various ices (such as water, methane. methanol. and nitrogen). The diversity in the spectra suggests that these objects represent a substantial range of original bulk compositions, including ices, silicates, and organic solids. The methods to model surface compositions are presented and possible cause of the spectral diversity are discussed.