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Title: Evidence of both molecular cloud and fluid chemistry in Ryugu regolith
The sulfur chemistry of (162173) Ryugu particles can be a powerful tracer of molecular cloud chemistry and small body processes, but it has not been well explored. We report identification of organosulfurs and a sulfate grain in two Ryugu particles, A0070 and A0093. The sulfate grain shows oxygen isotope ratios (δ17O = −11.0 ± 4.3 per mil, δ18O = −7.8 ± 2.3 per mil) that are akin to silicates in Ryugu but exhibit mass-independent sulfur isotopic fractionation (Δ33S = +5 ± 2 per mil). A methionine-like coating on the sulfate grain is isotopically anomalous (δ15N = +62 ± 2 per mil). Both the sulfate and organosulfurs can simultaneously form and survive during aqueous alteration within Ryugu’s parent body, under reduced conditions, low temperature, and a pH >7 in the presence of N-rich organic molecules. This work extends the heliocentric zone where anomalous sulfur, formed by selective photodissociation of H2S gas in the molecular cloud, is found.  more » « less
Award ID(s):
1819550
PAR ID:
10626888
Author(s) / Creator(s):
; ; ; ; ; ;
Publisher / Repository:
American Association for the Advancement of Science
Date Published:
Journal Name:
Science Advances
Volume:
10
Issue:
30
ISSN:
2375-2548
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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