A NEW ASTROBIOLOGICAL MODEL OF THE ATMOSPHERE OF TITAN

Journal Article · Sat Oct 01 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/829/2/79· OSTI ID:22667394

Willacy, K. ^[1]; Allen, M. ^[2]

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1. MS 169-507, Caltech/Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)
2. Caltech/Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

We present results of an investigation into the formation of nitrogen-bearing molecules in the atmosphere of Titan. We extend a previous model to cover the region below the tropopause, so the new model treats the atmosphere from Titan’s surface to an altitude of 1500 km. We consider the effects of condensation and sublimation using a continuous, numerically stable method. This is coupled with parameterized treatments of the sedimentation of the aerosols and their condensates, and the formation of haze particles. These processes affect the abundances of heavier species such as the nitrogen-bearing molecules, but have less effect on the abundances of lighter molecules. Removal of molecules to form aerosols also plays a role in determining the mixing ratios, particularly of HNC, HC{sub 3}N, and HCN. We find good agreement with the recently detected mixing ratios of C{sub 2}H{sub 5}CN, with condensation playing an important role in determining the abundance of this molecule below 500 km. Of particular interest is the chemistry of acrylonitrile (C{sub 2}H{sub 3}CN) which has been suggested by Stevenson et al. as a molecule that could form biological membranes in an oxygen-deficient environment. With the inclusion of haze formation, we find good agreement of our model predictions of acrylonitrile with the available observations.

• OSTI ID: 22667394
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 829; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
ACRYLONITRILE
AEROSOLS
HYDROCYANIC ACID
MOLECULES
NITROGEN
OXYGEN
SATELLITE ATMOSPHERES
SATELLITES
SATURN PLANET
SIMULATION
SURFACES
TROPOPAUSE