First in-situ detection of the cometary ammonium ion NH⁺₄ (protonated ammonia NH₃) in the coma of 67P/C-G near perihelion

Beth, A.; Altwegg, Kathrin; Balsiger, Hans; Berthelier, J.-J.; Calmonte, Ursina Maria; Combi, M.R.; De Keyser, J.; Dhooghe, F.; Fiethe, B.; Fuselier, S.A.; Galand, M.; Gasc, Sébastien; Gombosi, T.I.; Hansen, K.C.; Hässig, M.; Héritier, K.L.; Kopp, Ernest; Le Roy, Léna; Mandt, K.E.; Peroy, S.; ... (2017). First in-situ detection of the cometary ammonium ion NH⁺₄ (protonated ammonia NH₃) in the coma of 67P/C-G near perihelion. Monthly notices of the Royal Astronomical Society, 462(Suppl_1), S562-S572. Oxford University Press 10.1093/mnras/stw3370

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In this paper, we report the first in situ detection of the ammonium ion NH⁺₄ at 67P/Churyumov–Gerasimenko (67P/C-G) in a cometary coma, using the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Double Focusing Mass Spectrometer (DFMS). Unlike neutral and ion spectrometers onboard previous cometary missions, the ROSINA/DFMS spectrometer, when operated in ion mode, offers the capability to distinguish NH⁺₄ from H₂O⁺ in a cometary coma. We present here the ion data analysis of mass-to-charge ratios 18 and 19 at high spectral resolution and compare the results with an ionospheric model to put these results into context. The model confirms that the ammonium ion NH⁺₄ is one of the most abundant ion species, as predicted, in the coma near perihelion.

Item Type:

Journal Article (Original Article)


08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
10 Strategic Research Centers > Center for Space and Habitability (CSH)
08 Faculty of Science > Other Institutions > Emeriti, Faculty of Science

UniBE Contributor:

Altwegg, Kathrin, Balsiger, Hans, Calmonte, Ursina Maria, Gasc, Sébastien, Kopp, Ernest, Le Roy, Léna, Rubin, Martin, Sémon, Thierry, Tzou, Chia-Yu


500 Science > 520 Astronomy
600 Technology > 620 Engineering




Oxford University Press




Dora Ursula Zimmerer

Date Deposited:

14 Nov 2017 10:50

Last Modified:

05 Dec 2022 15:07

Publisher DOI:





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