Abstract
Experiments in quartz ampoules that simulate the saltation of quartz grains in a methane atmosphere show that the solid phase acquires a reddish color, reminiscent of the color observed on Triton, Pluto, and Charon. Reflection spectroscopy of the coated grains show a wide, continuous absorption spectrum peaking at near-UV wavelengths, in line with the reddish color. X-ray photoelectron spectroscopy indicates the grains are coated with a substance containing C-C and C-O bonds, and estimates the average thickness of the surface layer to 2.3 angstrom. Solid state Raman measurements of the coating shows a transition at 1540 cm(-1). A model is proposed to describe these measurements. The model is a polydiene, anchored to the quartz surface. Electron structure calculations show that a polydiene with around 8 CH units reproduces the measurements. AFM-IR experiments support this result. Our findings suggest a pathway for synthesis of complex molecules with C = C bonds on planets and moons with a solid surface and a methane-containing atmosphere.
Original language | English |
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Article number | 115023 |
Journal | Icarus |
Volume | 382 |
Number of pages | 7 |
ISSN | 0019-1035 |
DOIs | |
Publication status | Published - Aug 2022 |
Keywords
- Satellites
- Surfaces
- Spectroscopy
- Atmospheres
- Chemistry
- Prebiotic chemistry
- EXCITED-STATES
- PHOTOCHEMISTRY
- TRITON
- PLUTO