Ammonium salts are a reservoir of nitrogen on a cometary nucleus and possibly on some asteroids
- 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.
Author details: | Olivier PochORCiD, Istiqomah Istiqomah, Eric QuiricoORCiD, Pierre Beck, Bernard SchmittORCiD, Patrice TheuléORCiDGND, Alexandre FaureORCiDGND, Pierre Hily-BlantORCiD, Lydie Bonal, David KappelORCiDGND |
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DOI: | https://doi.org/10.1126/science.aaw7462 |
ISSN: | 1095-9203 |
ISSN: | 0036-8075 |
Title of parent work (English): | Science |
Publisher: | AAAS, American Association for the Advancement of Science |
Place of publishing: | Washington, DC |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/03/13 |
Publication year: | 2020 |
Release date: | 2024/03/15 |
Tag: | MU-M; bidirectional reflectance; exposed water ice; ice absorption features; interstellar ice; murchison meteorite; resolution infrared-spectroscopy; spectra; surface; young stellar objects |
Volume: | 367 |
Issue: | 6483 |
Article number: | eaaw7462 |
Number of pages: | 8 |
First page: | 1 |
Last Page: | 8 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 52 Astronomie / 520 Astronomie und zugeordnete Wissenschaften |
Peer review: | Referiert |