Variations of organic functional chemistry in carbonaceous matter from the asteroid 162173 Ryugu.
Bradley De GregorioGeorge D CodyRhonda M StroudA L David KilcoyneScott SandfordCorentin Le GuillouLarry R NittlerJens BaroschHikaru YabutaZita MartinsYoko KebukawaTaiga OkumuraMinako HashiguchiShohei YamashitaYasuo TakeichiYoshio TakahashiDaisuke WakabayashiCécile EngrandLaure BejachLydie BonalEric QuiricoLaurent RemusatJean DupratMaximilien Verdier-PaolettiSmail MostefaouiMutsumi KomatsuJeremie MathurinAlexandre DazziAriane Deniset-BesseauEmmanuel DartoisYusuke TamenoriHiroki SugaGilles MontagnacKanami KamideMiho ShigenakaMegumi MatsumotoYuma EnokidoMakoto YoshikawaTakanao SaikiSatoshi TanakaFuyuto TeruiSatoru NakazawaTomohiro UsuiMasanao AbeTatsuaki OkadaToru YadaMasahiro NishimuraAiko NakatoAkiko MiyazakiKasumi YogataHisayoshi YurimotoTomoki NakamuraTakaaki NoguchiRyuji OkazakiHiroshi NaraokaKanako SakamotoShogo TachibanaSei'ichiro WatanabeYuichi TsudaPublished in: Nature communications (2024)
Primordial carbon delivered to the early earth by asteroids and meteorites provided a diverse source of extraterrestrial organics from pre-existing simple organic compounds, complex solar-irradiated macromolecules, and macromolecules from extended hydrothermal processing. Surface regolith collected by the Hayabusa2 spacecraft from the carbon-rich asteroid 162173 Ryugu present a unique opportunity to untangle the sources and processing history of carbonaceous matter. Here we show carbonaceous grains in Ryugu can be classified into three main populations defined by spectral shape: Highly aromatic (HA), Alkyl-Aromatic (AA), and IOM-like (IL). These carbon populations may be related to primordial chemistry, since C and N isotopic compositions vary between the three groups. Diffuse carbon is occasionally dominated by molecular carbonate preferentially associated with coarse-grained phyllosilicate minerals. Compared to related carbonaceous meteorites, the greater diversity of organic functional chemistry in Ryugu indicate the pristine condition of these asteroid samples.