Atmospheric Chemistry of Titan Options

[Juramike]

Here is a "Benzene-O-Vision" graphic showing the amount of benzene and phenyl radicals at high altitudes on Titan. This is based on detections of benzene and phenyl radical (which recombined in the sample chamber to make benzene) using the INMS instrument during closest approach. The numbers are normalized to constant pressure altitude, roughly 1000 km.



The data was taken from Table 1 in: Vuitton et al, Journal of Geophysical Research 113 (2008) E05007. "Formation and distribution of benzene on Titan". doi: 10.1029/2007JE002997 [EDIT 5/24/10: Article freely available here] and overlaid on a map of Titan.

The authors mentioned that the errors in these measurements are 20%.

These detections are well above the detached haze layer. Most are at the same sun azimuth angle. (T23 observation had the lowest angle.) Assuming that the temporal difference is minimal (each dot is from a different flyby), there doesn't appear to be an obvious correlation with latitude.

This graphic does show that benzene is present even waaaay up in the thermosphere and ionosphere.

[Juramike]

Nitrogen does get incorporated. It is primarily in the form of nitriles (RCN). There should be surface deposits of cyanide (HCN), acetonitrile (CH3CN), and acrylonitrile (H2C=CHCN), cyanoacetylene (HCCCN), and cyanogen (NCCN).

Tholins are also thought to be rich in nitrile functionalities.

I'm still digging through some of the literature, but it seems that the literature rates for nitrile formation are a little less nailed down than for hydrocarbon formation processes. The key starting point seems to be molecular dinitrogen getting blown apart to form nitrogen radical carbene (.:N:).