Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids.
Journal
Science (New York, N.Y.)
ISSN: 1095-9203
Titre abrégé: Science
Pays: United States
ID NLM: 0404511
Informations de publication
Date de publication:
13 03 2020
13 03 2020
Historique:
received:
21
01
2019
revised:
11
10
2019
accepted:
14
02
2020
entrez:
14
3
2020
pubmed:
14
3
2020
medline:
14
3
2020
Statut:
ppublish
Résumé
The measured nitrogen-to-carbon ratio in comets is lower than for the Sun, a discrepancy which could be alleviated if there is an unknown reservoir of nitrogen in comets. The nucleus of comet 67P/Churyumov-Gerasimenko exhibits an unidentified broad spectral reflectance feature around 3.2 micrometers, which is ubiquitous across its surface. On the basis of laboratory experiments, we attribute this absorption band to ammonium salts mixed with dust on the surface. The depth of the band indicates that semivolatile ammonium salts are a substantial reservoir of nitrogen in the comet, potentially dominating over refractory organic matter and more volatile species. Similar absorption features appear in the spectra of some asteroids, implying a compositional link between asteroids, comets, and the parent interstellar cloud.
Identifiants
pubmed: 32165559
pii: 367/6483/eaaw7462
doi: 10.1126/science.aaw7462
pii:
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Subventions
Organisme : Swiss National Science Foundation
Pays : Switzerland
Organisme : European Research Council
Pays : International
Informations de copyright
Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.