Identification and characterization of a new ensemble of cometary organic molecules

N Hänni; K Altwegg; M Combi; S A Fuselier; J De Keyser; M Rubin; S F Wampfler

doi:10.1038/s41467-022-31346-9

Identification and characterization of a new ensemble of cometary organic molecules

Nat Commun. 2022 Jun 25;13(1):3639. doi: 10.1038/s41467-022-31346-9.

Authors

N Hänni¹, K Altwegg², M Combi³, S A Fuselier^{4

5}, J De Keyser⁶, M Rubin², S F Wampfler⁷

Affiliations

¹ Physics Institute, Space Research & Planetary Sciences, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland. nora.haenni@unibe.ch.
² Physics Institute, Space Research & Planetary Sciences, University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland.
³ Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA.
⁴ Space Science Directorate, Southwest Research Institute, San Antonio, TX, USA.
⁵ Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, TX, USA.
⁶ Royal Belgian Institute for Space Aeronomy, BIRA-IASB, Brussels, Belgium.
⁷ Center for Space and Habitability, University of Bern, Gesellschaftsstrasse 6, 3012, Bern, Switzerland.

Abstract

In-situ study of comet 1P/Halley during its 1986 apparition revealed a surprising abundance of organic coma species. It remained unclear, whether or not these species originated from polymeric matter. Now, high-resolution mass-spectrometric data collected at comet 67P/Churyumov-Gerasimenko by ESA's Rosetta mission unveil the chemical structure of complex cometary organics. Here, we identify an ensemble of individual molecules with masses up to 140 Da while demonstrating inconsistency of the data with relevant amounts of polymeric matter. The ensemble has an average composition of C₁H_1.56O_0.134N_0.046S_0.017, identical to meteoritic soluble organic matter, and includes a plethora of chain-based, cyclic, and aromatic hydrocarbons at an approximate ratio of 6:3:1. Its compositional and structural properties, except for the H/C ratio, resemble those of other Solar System reservoirs of organics-from organic material in the Saturnian ring rain to meteoritic soluble and insoluble organic matter -, which is compatible with a shared prestellar history.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Extraterrestrial Environment* / chemistry
Mass Spectrometry
Meteoroids*
Solar System