Evidence of ammonium salts in comet 67P as explanation for the nitrogen depletion in cometary comae - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Nature Astronomy Année : 2020

Evidence of ammonium salts in comet 67P as explanation for the nitrogen depletion in cometary comae

Résumé

Cometary comae are generally depleted in nitrogen. The main carriers for volatile nitrogen in comets are NH3 and HCN. It is known that ammonia readily combines with many acids, such as HCN, HNCO and HCOOH, encountered in the interstellar medium as well as in cometary ice to form ammonium salts (NH4+X-) at low temperatures. Ammonium salts, which can have a substantial role in prebiotic chemistry, are hard to detect in space as they are unstable in the gas phase and their infrared signature is often hidden by thermal radiation or by, for example, OH in minerals. Here we report the presence of all possible sublimation products of five different ammonium salts in the comet 67P/Churyumov-Gerasimenko measured by the ROSINA instrument onboard Rosetta. The relatively high sublimation temperatures of the salts leads to an apparent lack of volatile nitrogen in the coma. This then also explains the observed trend of higher NH3/H2O ratios with decreasing perihelion distances in comets.
Fichier principal
Vignette du fichier
1911.13005.pdf (2.29 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

insu-02411099 , version 1 (11-03-2020)

Identifiants

Citer

Kathrin Altwegg, Hans Balsiger, Jean-Jacques Berthelier, Christelle Briois, Mike Combi, et al.. Evidence of ammonium salts in comet 67P as explanation for the nitrogen depletion in cometary comae. Nature Astronomy, 2020, 4, pp.533-540. ⟨10.1038/s41550-019-0991-9⟩. ⟨insu-02411099⟩
118 Consultations
118 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More