Remote sensing D/H ratios in methane ice: Temperature-dependent absorption coefficients of CH3D in methane ice and in nitrogen ice
✍ Scribed by W.M. Grundy; S.J. Morrison; M.J. Bovyn; S.C. Tegler; D.M. Cornelison
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 985 KB
- Volume
- 212
- Category
- Article
- ISSN
- 0019-1035
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✦ Synopsis
The existence of strong absorption bands of singly deuterated methane (CH 3 D) at wavelengths where normal methane (CH 4 ) absorbs comparatively weakly could enable remote measurement of D/H ratios in methane ice on outer Solar System bodies. We performed laboratory transmission spectroscopy experiments, recording spectra at wavelengths from 1 to 6 lm to study CH 3 D bands at 2.47, 2.87, and 4.56 lm, wavelengths where ordinary methane absorption is weak. We report temperature-dependent absorption coefficients of these bands when the CH 3 D is diluted in CH 4 ice and also when it is dissolved in N 2 ice, and describe how these absorption coefficients can be combined with data from the literature to simulate arbitrary D/H ratio absorption coefficients for CH 4 ice and for CH 4 in N 2 ice. We anticipate these results motivating new telescopic observations to measure D/H ratios in CH 4 ice on Triton, Pluto, Eris, and Makemake.