Vertical distribution of cyclopropenylidene and propadiene in the atmosphere of Titan

TL;DR

This study investigates the vertical distribution of cyclopropenylidene and propadiene in Titan's atmosphere, highlighting recent molecular detections and the role of ion chemistry in organic molecule formation.

Contribution

It combines observational data with photochemical modeling to explain the distribution of specific organic molecules in Titan's atmosphere, emphasizing ion chemistry's significance.

Findings

Detection of C3 molecules and C6H6 in Titan's atmosphere.

Ion chemistry significantly influences molecule production above 1000 km.

Model successfully accounts for recent molecular observations.

Abstract

Titan's atmosphere is a natural laboratory for exploring the photochemical synthesis of organic molecules. Significant recent advances in the study of the atmosphere of Titan include: (a) detection of C$_3$ molecules: C$_3$H$_6$, CH$_2$CCH$_2$, c-C$_3$H$_2$, and (b) retrieval of C$_6$H$_6$, which is formed primarily via C$_3$ chemistry, from Cassini-UVIS data. The detection of $c$-C$_3$H$_2$ is of particular significance since ring molecules are of great astrobiological importance. Using the Caltech/JPL KINETICS code, along with the best available photochemical rate coefficients and parameterized vertical transport, we are able to account for the recent observations. It is significant that ion chemistry, reminiscent of that in the interstellar medium, plays a major role in the production of c-C$_3$H$_2$ above 1000 km.