PAHs, hydrocarbons, and dimethylsulfides in Asteroid Ryugu samples A0106 and C0107 and the Orgueil (CI1) meteorite

Evaluating the molecular distribution of organic compounds in pristine extraterrestrial materials is cornerstone to understanding the abiotic synthesis of organics and allows us to better understand the molecular diversity available during the formation of our solar system and before the origins of life on Earth. In this work, we identify multiple organic compounds in solvent extracts of asteroid Ryugu samples A0106 and C0107 and the Orgueil meteorite using two-dimensional gas chromatography and time-of-flight high resolution mass spectrometry (GCxGC-HRMS). Our analyses found similarities between the molecular distribution of organic compounds in Ryugu and the CI carbonaceous chondrite Orgueil. Specifically, several PAHs and organosulfides were found in Ryugu and Orgueil suggesting an interstellar and parent body origin for these compounds. We also evaluated the common relationship between Ryugu, Orgueil, and comets, such as Wild-2; however, until comprehensive compound-specific isotopic analyses for these organic species are undertaken, and until the effects of parent body processes and Earth's weathering processes on meteoritic organics are better understood, their parent-daughter relationships will remain unanswered. Finally, the study of organic compounds in Ryugu samples and the curation practices for the future preservation of these unvaluable materials are also of special interest for future sample return missions, including NASA's OSIRIS-REx asteroid sample return mission.

Automated summary

Evaluating the molecular distribution of organic compounds in pristine extraterrestrial materials is crucial for understanding the synthesis and diversity of organics before the origins of life on Earth. This study identified multiple organic compounds in samples from asteroid Ryugu and the Orgueil meteorite, suggesting an interstellar and parent body origin for these compounds. However, further analysis is required to determine their parent-daughter relationships and the effects of various processes on these meteoritic organics. The findings also have implications for future sample return missions.