Deuterated Methane Observed on Saturn

Absorptions for the $\nu _{2}$ band of deuterated methane (CH$_{3}$D) have been observed in the 5-micron spectrum of Saturn, obtained with a Fourier transform spectrometer. Analysis of the band yields a CH$_{3}$D abundance of 2.6 ± 0.8 centimeter-amagat and a temperature of 175 ± 30 K for the mean l...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 1978-07, Vol.201 (4353), p.343-345
Main Authors: Fink, Uwe, Larson, Harold P.
Format: Article
Language:English
Subjects:
Deuterium
Fractionation
Jupiter
Line spectra
Methane
Radiation counters
Saturn
Saturn atmosphere
Space based observatories
Telluric lines
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Absorptions for the $\nu _{2}$ band of deuterated methane (CH$_{3}$D) have been observed in the 5-micron spectrum of Saturn, obtained with a Fourier transform spectrometer. Analysis of the band yields a CH$_{3}$D abundance of 2.6 ± 0.8 centimeter-amagat and a temperature of 175 ± 30 K for the mean level of spectroscopic line formation. This temperature indicates that a substantial portion of Saturn's flux at 5 microns is due to thermal radiation, and that we are therefore looking fairly deep into its atmosphere, as is the case for the Jupiter 5-micron window. This CH$_{3}$D abundance leads to a deuterium/hydrogen ratio of about 2 × 10$^{-5}$ in Saturn's atmosphere. This ratio is much lower than the terrestrial value but comparable to that determined for Jupiter and may be taken as representative of the deuterium/hydrogen ratio in the solar system at the time of its formation.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.201.4353.343