The Composition and Chemistry of Titan’s Atmosphere

By Keith Cowing
Status Report
February 28, 2024
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The Composition and Chemistry of Titan’s Atmosphere
The atmosphere of Titan seen by Cassini’s Imaging Science Subsystem (ISS). The dayside image (December 16th 2011) shows Titan’s ubiquitous golden haze, opaque to visible light. A darker haze collar is seen around the north pole, along with fainter haze hoods over both the north and south poles, thought to be created by the interaction between chemical and dynamical processes. The nightside image (PIA14924, June 6th 2012, range: 216,000 km) clearly shows the detached atmospheric haze surrounding the entire limb and an elevated stratospheric condensate cloud over the south pole, thought to be composed at least partly of HCN. Image credit: NASA/JPL-Caltech/Space Science Institute/CICLOPS, with reprocessing by Kevin M. Gill.

In this article I summarize the current state of knowledge about the composition of Titan’s atmosphere, and our current understanding of the suggested chemistry that leads to that observed composition.

I begin with our present knowledge of the atmospheric composition, garnered from a variety of measurements including Cassini-Huygens, the Atacama Large Millimeter/submillimeter Array (ALMA), and other ground and space-based telescopes.

This review focuses on the typical vertical profiles of gases at low latitudes, rather than global and temporal variations. The main body of the paper presents a chemical description of how complex molecules are believed to arise from simpler species, considering all known ‘stable’ molecules – those that have been uniquely identified in the neutral atmosphere.

The last section of the paper is devoted to the gaps in our present knowledge of Titan’s chemical composition and how further work may fill those gaps.

Conor A. Nixon

Comments: 177 pages, 45 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2402.17116 [astro-ph.EP] (or arXiv:2402.17116v1 [astro-ph.EP] for this version)
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From: Conor Nixon
[v1] Tue, 27 Feb 2024 01:24:44 UTC (25,378 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻