An atmospheric origin for a HCN-derived polymer on Titan

Zoé Perrin (1) , Nathalie Carrasco (1) , Audrey Chatain (1) , Lora Jovanovic (1) , N. Ruscassier (2) , Ludovic Vettier (1) , Guy Cernogora (1)

1 PLANETO - LATMOS
2 LGPM - Laboratoire de Génie des Procédés et Matériaux

Titan’s haze is strongly suspected to be an HCN-derived polymer, but despite the first in situ measurements by the ESA-Huygens space probe, its chemical composition and formation process remain largely unknown. To investigate this question, we simulated in the laboratory, the atmospheric haze for- mation process. We synthesized analogues of Titan’s haze, named Titan tholins, in an irradiated N2–CH4 gas mixture, mimicking Titan’s upper atmosphere chemistry. HCN was monitored in situ in the gas phase simultaneously with the formation and evolution of the haze particles. We show that HCN is produced as long as the particles are absent, and is then progressively consumed when the particles appear and grow. This work highlights HCN as an effective precursor of Titan’s haze and confirms the HCN-derived polymer nature of the haze.

Keywords: HCN-polymers; microphysical evolution

Domains: Sciences of the Universe [physics]

Zoé Perrin, Nathalie Carrasco, Audrey Chatain, Lora Jovanovic, N. Ruscassier, et al.. An atmospheric origin for a HCN-derived polymer on Titan. SF2A-2021: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics, Jun 2021, On Line, France. pp.59-62. ⟨insu-03835791⟩