[X] My Assistant

[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]

Ethyl radical (.C2H5) [.CH2CH3] - key intermediate

The direct photodissociation of a C-H bond in ethane is NOT the major process to ethyl radical. Instead, it is this:



The dominant process to ethyl radical is C-H photodissociation to make acetylene radical (.CCH), followed by it plucking a hydrogen radical from ethane to then generate ethyl radical. So in a sense it is an overall photodissociation of the ethane C-H bond, but it goes through an acetylene middleman.

Ethyl radical is important in the generation of propane, the fourth most abundant liquid on Titan. (after methane, ethane, and molecular nitrogen).