Ionizing radiation exposure on Arrokoth shapes a sugar world.

Autor: Zhang C; Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.; W.M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822., Leyva V; Université Côte d'Azur, Institut de Chimie de Nice, UMR 7272 CNRS, 06108 Nice, France., Wang J; Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.; W.M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822., Turner AM; Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.; W.M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822., Mcanally M; Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.; W.M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822., Herath A; Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.; W.M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822., Meinert C; Université Côte d'Azur, Institut de Chimie de Nice, UMR 7272 CNRS, 06108 Nice, France., Young LA; Department of Space Studies, Southwest Research Institute, Boulder, CO 80302., Kaiser RI; Department of Chemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.; W.M. Keck Laboratory in Astrochemistry, University of Hawaii at Mānoa, Honolulu, HI 96822.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2024 Jun 11; Vol. 121 (24), pp. e2320215121. Date of Electronic Publication: 2024 Jun 03.
DOI: 10.1073/pnas.2320215121
Abstrakt: The Kuiper Belt object (KBO) Arrokoth, the farthest object in the Solar System ever visited by a spacecraft, possesses a distinctive reddish surface and is characterized by pronounced spectroscopic features associated with methanol. However, the fundamental processes by which methanol ices are converted into reddish, complex organic molecules on Arrokoth's surface have remained elusive. Here, we combine laboratory simulation experiments with a spectroscopic characterization of methanol ices exposed to proxies of galactic cosmic rays (GCRs). Our findings reveal that the surface exposure of methanol ices at 40 K can replicate the color slopes of Arrokoth. Sugars and their derivatives (acids, alcohols) with up to six carbon atoms, including glucose and ribose-fundamental building block of RNA-were ubiquitously identified. In addition, polycyclic aromatic hydrocarbons (PAHs) with up to six ring units ( 13 C 22 H 12 ) were also observed. These sugars and their derivatives along with PAHs connected by unsaturated linkers represent key molecules rationalizing the reddish appearance of Arrokoth. The formation of abundant sugar-related molecules dubs Arrokoth as a sugar world and provides a plausible abiotic preparation route for a key class of biorelevant molecules on the surface of KBOs prior to their delivery to prebiotic Earth.
Competing Interests: Competing interests statement:The authors declare no competing interest.
Databáze: MEDLINE
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