Tholins as coloring agents on outer Solar System bodies

The red colors of many solid bodies in outer Solar System may be caused by tholins, which are refractory organic complexes, incorporated in their surface materials. Tholins synthesized in the laboratory are shown to match the colors of these bodies when their optical properties are used in rigorous...

Full description

Saved in:
Bibliographic Details
Published inAdvances in space research Vol. 36; no. 2; pp. 178 - 183
Main Authors Cruikshank, Dale P., Imanaka, Hiroshi, Dalle Ore, Cristina M.
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 2005
Subjects
Infrared spectroscopy
Organic chemistry
Outer Solar System
Tholin
Titan
Organic chemistry
Infrared spectroscopy
Tholin
Outer Solar System
Titan
Online AccessGet full text

Cover

More Information
Summary:The red colors of many solid bodies in outer Solar System may be caused by tholins, which are refractory organic complexes, incorporated in their surface materials. Tholins synthesized in the laboratory are shown to match the colors of these bodies when their optical properties are used in rigorous scattering models. We review recent successes in modeling the spectra of icy outer Solar System bodies with tholins as the coloring agents. New work on the systematic laboratory synthesis and analysis of tholins made by cold plasma discharge in mixtures of gaseous CH 4/N 2 shows that the composition of the tholin depends strongly on the pressure in the reaction chamber, and only weakly on the mixing fraction of CH 4 relative to N 2. In tholins made at high pressure (e.g., 23 hPa) the abundance of aliphatic hydrocarbons is greater and the abundance of aromatic hydrocarbons is less than in tholins made at low pressure (e.g., 0.13 hPa). Tholins made at low deposition pressures show a greater abundance of N–H bonds.
ISSN:0273-1177
1879-1948
DOI:10.1016/j.asr.2005.07.026