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Popeza ndi ofooka komanso olemera mu zinthu zachilengedwe, ma asteroid amtundu wa C akhoza kukhala amodzi mwa magwero akuluakulu a madzi padziko lapansi. Pakadali pano, ma chondrite okhala ndi kaboni amapereka lingaliro labwino kwambiri la kapangidwe kake ka mankhwala, koma chidziwitso chokhudza ma meteorite chimasokonekera: mitundu yolimba kwambiri yokha ndi yomwe imapulumuka kulowa mumlengalenga kenako n’kulumikizana ndi chilengedwe cha dziko lapansi. Apa tikuwonetsa zotsatira za kafukufuku wozama wa volumetric ndi microanalytical wa tinthu tating'onoting'ono ta Ryugu tomwe tinaperekedwa ku Dziko Lapansi ndi chombo cha Hayabusa-2. Tinthu ta Ryugu tikuwonetsa kufanana kwa kapangidwe kake ndi ma chondrite a CI (mtundu wa Iwuna) osagawika koma osinthidwa ndi madzi, omwe amagwiritsidwa ntchito kwambiri ngati chizindikiro cha kapangidwe kake ka dongosolo la dzuwa. Chitsanzochi chikuwonetsa ubale wovuta pakati pa zinthu zachilengedwe zolemera za aliphatic ndi ma silicate odulidwa ndipo chikuwonetsa kutentha kwakukulu kwa pafupifupi 30 °C panthawi ya kukokoloka kwa madzi. Tapeza kuchuluka kwa deuterium ndi diazonium komwe kumagwirizana ndi chiyambi cha extrasolar. Tinthu ta Ryugu ndi zinthu zachilendo zosadetsedwa komanso zosagwirizana zomwe zidaphunziridwapo ndipo zimagwirizana bwino ndi kapangidwe ka dongosolo la dzuwa.
Kuyambira mu June 2018 mpaka November 2019, chombo cha Hayabusa2 cha Japan Aerospace Exploration Agency (JAXA) chinachita kafukufuku wakutali wa Ryugu wa asteroid. Deta yochokera ku Near Infrared Spectrometer (NIRS3) ku Hayabusa-2 ikusonyeza kuti Ryugu ikhoza kukhala yopangidwa ndi zinthu zofanana ndi ma chondrites a carbonaceous omwe amatenthedwa ndi kutentha komanso/kapena shock-metamorphic. Chofanana kwambiri ndi CY chondrite (mtundu wa Yamato) 2. Albedo yotsika ya Ryugu ikhoza kufotokozedwa ndi kupezeka kwa zinthu zambiri zokhala ndi kaboni, komanso kukula kwa tinthu tating'onoting'ono, porosity, ndi zotsatira za nyengo. Chombo cha Hayabusa-2 chinafika kawiri ndi kusonkhanitsa zitsanzo pa Ryuga. Pakutera koyamba pa February 21, 2019, zinthu zapamwamba zinapezeka, zomwe zinasungidwa mu compartment A ya return capsule, ndipo pakufika kwachiwiri pa July 11, 2019, zinthuzo zinasonkhanitsidwa pafupi ndi crater yopangidwa ndi impactor yaying'ono yonyamulika. Zitsanzozi zimasungidwa mu Ward C. Kufotokozera koyamba kwa tinthu tating'onoting'ono tosawonongeka mu Gawo 1 m'zipinda zapadera, zosadetsedwa komanso zodzaza nayitrogeni m'malo oyendetsedwa ndi JAXA kunasonyeza kuti tinthu tating'onoting'ono ta Ryugu tinali ofanana kwambiri ndi ma chondrites a CI4 ndipo tinawonetsa "kusiyana kwakukulu"3. Kugawika kwa Ryugu komwe kumawoneka ngati kotsutsana, kofanana ndi ma chondrites a CY kapena CI, kumatha kuthetsedwa kokha ndi kufotokoza mwatsatanetsatane kwa tinthu ta Ryugu tomwe timakhala ndi isotopic, elemental, ndi mineral. Zotsatira zomwe zaperekedwa pano zimapereka maziko olimba odziwira kuti ndi kufotokozera kotani kwa tinthu tating'onoting'ono ta Ryugu komwe kungakhale kothekera kwambiri.
Ma pellet asanu ndi atatu a Ryugu (pafupifupi 60mg onse), anayi ochokera ku Chamber A ndi anayi ochokera ku Chamber C, adapatsidwa gawo lachiwiri kuti aziyang'anira gulu la Kochi. Cholinga chachikulu cha kafukufukuyu ndikufotokozera za mtundu, chiyambi ndi mbiri ya kusintha kwa asteroid Ryugu, ndikulemba kufanana ndi kusiyana ndi zitsanzo zina zodziwika zakunja kwa dziko lapansi monga ma chondrites, tinthu tating'onoting'ono ta fumbi la interplanetary (IDPs) ndi ma comets obwerera. Zitsanzo zomwe zasonkhanitsidwa ndi ntchito ya NASA ya Stardust.
Kusanthula mwatsatanetsatane kwa mchere wa tirigu zisanu za Ryugu (A0029, A0037, C0009, C0014 ndi C0068) kunawonetsa kuti zimapangidwa makamaka ndi ma phyllosilicates abwino ndi osalala (~64–88 vol.%; Chithunzi 1a, b, Chithunzi Chowonjezera 1). ndi tebulo lowonjezera 1). Ma phyllosilicates okongola amapezeka ngati ma pinnate aggregates (mpaka ma microns makumi ambiri) m'ma matrices abwino, olemera a phyllosilicate (osakwana ma microns ochepa kukula). Tinthu ta silicate tomwe timayikidwa m'magawo ndi ma serpentine-saponite symbionts (Chithunzi 1c). Mapu a (Si + Al)-Mg-Fe akuwonetsanso kuti matrix ya silicate yokhala ndi magawo ambiri ili ndi kapangidwe kapakati pakati pa serpentine ndi saponite (Chithunzi 2a, b). Matrix ya phyllosilicate ili ndi mchere wa carbonate (~2–21 vol.%), mchere wa sulfide (~2.4–5.5 vol.%), ndi magnetite (~3.6–6.8 vol.%). Chimodzi mwa tinthu tating'onoting'ono tomwe tafufuzidwa mu kafukufukuyu (C0009) chinali ndi pang'ono (~0.5 vol.%) ya silicates ya anhydrous (olivine ndi pyroxene), zomwe zingathandize kuzindikira gwero la zinthu zomwe zinapanga miyala yaiwisi ya Ryugu5. Silicate ya anhydrous iyi ndi yosowa kwambiri mu ma pellets a Ryugu ndipo inapezeka bwino mu pellet ya C0009. Ma carbonates amapezeka mu matrix ngati zidutswa (zosakwana ma microns mazana angapo), makamaka dolomite, yokhala ndi calcium carbonate yochepa ndi brinell. Magnetite imapezeka ngati tinthu tating'onoting'ono, ma framboid, ma plaque, kapena ma aggregates ozungulira. Ma sulfides amaimiridwa makamaka ndi pyrrhotite mu mawonekedwe a ma prisms/maplates osasinthasintha a hexagonal kapena laths. Matrix ili ndi kuchuluka kwakukulu kwa submicron pentlandite kapena kuphatikiza ndi pyrrhotite. Magawo olemera ndi kaboni (osakwana 10 µm kukula) amapezeka paliponse mu matrix yolemera ndi phyllosilicate. Magawo olemera ndi kaboni (osakwana 10 µm kukula) amapezeka paliponse mu matrix yolemera ndi phyllosilicate. Богатые углеродом фазы (размером <10 мкм) встречаются повсеместно в богатой филлосиликатами матрице. Magawo olemera ndi kaboni (osakwana 10 µm kukula) amapezeka paliponse mu matrix yolemera ndi phyllosilicate.富含碳的相（尺寸<10 µm）普遍存在于富含层状硅酸盐的基质中。富含碳的相（尺寸<10 µm）普遍存在于富含层状硅酸盐的基质中。 Богатые углеродом фазы (размером <10 мкм) преобладают в богатой филлосиликатами матрице. Magawo olemera ndi kaboni (osapitirira 10 µm kukula) amapezeka kwambiri mu matrix yolemera ndi phyllosilicate.Michere ina yowonjezera ikuwonetsedwa mu Supplementary Table 1. Mndandanda wa mchere womwe wapezeka kuchokera ku X-ray diffraction pattern ya C0087 ndi A0029 ndi A0037 mixture umagwirizana kwambiri ndi womwe wapezeka mu CI (Orgueil) chondrite, koma umasiyana kwambiri ndi CY ndi CM (Mighei type) chondrites (Chithunzi 1 ndi deta yowonjezera ndi Chithunzi Chowonjezera 2). Kuchuluka kwa zinthu zonse mu Ryugu grains (A0098, C0068) kumagwirizananso ndi chondrite 6 CI (data yowonjezera, Chithunzi 2 ndi Table Yowonjezera 2). Mosiyana ndi zimenezi, CM chondrites zimachepa mu zinthu zosinthasintha pang'ono komanso zosinthasintha kwambiri, makamaka Mn ndi Zn, ndipo zimakhala zapamwamba mu zinthu zotsutsana7. Kuchuluka kwa zinthu zina kumasiyana kwambiri, zomwe zingakhale chiwonetsero cha kusiyana kwachilengedwe kwa chitsanzo chifukwa cha kukula kochepa kwa tinthu tating'onoting'ono ndi kusamvana komwe kumachitika chifukwa cha zitsanzo. Makhalidwe onse a petrological, mineralological ndi elemental amasonyeza kuti tirigu wa Ryugu ndi wofanana kwambiri ndi ma chondrites CI8,9,10. Chosiyana kwambiri ndi kusowa kwa ferrihydrite ndi sulfate mu tirigu wa Ryugu, zomwe zikusonyeza kuti mchere uwu mu ma chondrites a CI unapangidwa ndi nyengo ya dziko lapansi.
a, Chithunzi cha X-ray cha Composite cha Mg Kα (wofiira), Ca Kα (wobiriwira), Fe Kα (buluu), ndi S Kα (wachikasu) gawo lopukutidwa louma C0068. Gawoli lili ndi silicates zogawanika (zofiira: ~88 vol%), carbonates (dolomite; wobiriwira wopepuka: ~1.6 vol%), magnetite (buluu: ~5.3 vol%) ndi sulfides (chikasu: sulfide = ~2.5% vol. essay. b, chithunzi cha dera la contour mu ma electron osweka kumbuyo pa a. Bru - wosakhwima; Dole - dolomite; FeS ndi sulfide yachitsulo; Mag - magnetite; madzi - mwala wa sopo; Srp - serpentine. c, chithunzi cha high-resolution transmission electron microscopy (TEM) cha intergrowth yachizolowezi ya saponite-serpentine yomwe ikuwonetsa ma serpentine ndi saponite lattice bands a 0.7 nm ndi 1.1 nm, motsatana.
Kapangidwe ka matrix ndi silicate yoyikidwa (pa %) ya tinthu ta Ryugu A0037 (mabwalo ofiira olimba) ndi C0068 (mabwalo abuluu olimba) kakuwonetsedwa mu dongosolo la (Si+Al)-Mg-Fe ternary. a, Zotsatira za Electron Probe Microanalysis (EPMA) zomwe zawonetsedwa motsutsana ndi ma chondrites a CI (Ivuna, Orgueil, Alais)16 zomwe zawonetsedwa mu imvi kuti ziyerekezedwe. b, Kusanthula kwa Scanning TEM (STEM) ndi kusanthula kwa energy dispersive X-ray spectroscopy (EDS) komwe kwawonetsedwa poyerekeza ndi Orgueil9 ndi Murchison46 meteorites ndi hydrated IDP47. Ma phyllosilicates opyapyala komanso opyapyala adasanthulidwa, kupewa tinthu tating'onoting'ono ta iron sulfide. Mizere yokhala ndi madontho mu a ndi b ikuwonetsa mizere yosungunuka ya saponite ndi serpentine. Kapangidwe ka iron-rich mu a kangakhale chifukwa cha tinthu ta submicron iron sulfide mkati mwa tinthu ta silicate toyikidwa, zomwe sizingachotsedwe ndi kusanthula kwa EPMA. Ma data point okhala ndi Si yambiri kuposa saponite mu b akhoza kuyambitsidwa ndi kukhalapo kwa zinthu zolemera za silicon zomwe zili ndi nanosized amorphous m'kati mwa phyllosilicate layer. Chiwerengero cha kusanthula: N=69 ya A0037, N=68 ya EPMA, N=68 ya C0068, N=19 ya A0037 ndi N=27 ya C0068 ya STEM-EDS. c, mapu a isotope a tinthu ta trioxy Ryugu C0014-4 poyerekeza ndi ma chondrite values ​​​​CI (Orgueil), CY (Y-82162) ndi deta ya mabuku (CM ndi C2-ung)41,48,49. Tapeza deta ya Orgueil ndi Y-82162 meteorites. CCAM ndi mzere wa mchere wa anhydrous carbonaceous chondrite, TFL ndi mzere wogawa dziko. d, mamapu a Δ17O ndi δ18O a tinthu ta Ryugu C0014-4, CI chondrite (Orgueil), ndi CY chondrite (Y-82162) (kafukufukuyu). Δ17O_Ryugu: Mtengo wa Δ17O C0014-1. Δ17O_Orgueil: Mtengo wapakati wa Δ17O wa Orgueil. Δ17O_Y-82162: Mtengo wapakati wa Δ17O wa Y-82162. Deta ya CI ndi CY kuchokera m'mabuku 41, 48, 49 yawonetsedwanso kuti iyerekezedwe.
Kusanthula kwa mpweya wambiri wa isotope kunachitika pa chitsanzo cha 1.83 mg cha zinthu zotengedwa kuchokera ku C0014 yopyapyala pogwiritsa ntchito laser fluorination (Njira). Poyerekeza, tinalemba makope asanu ndi awiri a Orgueil (CI) (kulemera konse = 8.96 mg) ndi makope asanu ndi awiri a Y-82162 (CY) (kulemera konse = 5.11 mg) (Table Supplementary 3).
Pa chithunzi 2d chikuwonetsa kusiyana komveka bwino kwa Δ17O ndi δ18O pakati pa tinthu tating'onoting'ono ta Orgueil ndi Ryugu tomwe timalemera kwambiri poyerekeza ndi Y-82162. Δ17O ya tinthu ta Ryugu C0014-4 ndi yokwera kuposa ya tinthu ta Orgeil, ngakhale kuti timagwirizana pa 2 sd. Tinthu ta Ryugu tili ndi Δ17O yokwera kwambiri poyerekeza ndi Orgeil, yomwe ingasonyeze kuipitsidwa kwa dziko lapansi kuyambira nthawi yophukira mu 1864. Kusakhazikika kwa nyengo m'chilengedwe cha dziko lapansi11 kumapangitsa kuti mpweya wa mlengalenga ukhale wochuluka, zomwe zimapangitsa kuti kusanthula konse kukhale pafupi ndi mzere wogawa dziko lapansi (TFL). Izi zikugwirizana ndi deta ya mineralological (yomwe idakambidwa kale) kuti tirigu ta Ryugu tilibe ma hydrate kapena sulfates, pomwe Orgeil ali nawo.
Kutengera ndi deta ya mineralogical yomwe ili pamwambapa, zotsatirazi zikuthandizira mgwirizano pakati pa tirigu wa Ryugu ndi ma chondrite a CI, koma sizikutanthauza kuti pali mgwirizano pakati pa ma chondrite a CY. Mfundo yakuti tirigu wa Ryugu sugwirizana ndi ma chondrite a CY, omwe amasonyeza zizindikiro zomveka bwino za mineralogy yosowa madzi m'thupi, ndi yodabwitsa. Kuwona kwa Ryugu m'mlengalenga kukuwonetsa kuti yakhala ikuvutika ndi madzi m'thupi ndipo chifukwa chake mwina imapangidwa ndi zinthu za CY. Zifukwa za kusiyana kumeneku sizikudziwika bwino. Kusanthula kwa isotope ya okosijeni ya tinthu tina ta Ryugu kwaperekedwa mu pepala logwirizana 12. Komabe, zotsatira za deta yowonjezerekayi zikugwirizananso ndi mgwirizano pakati pa tinthu ta Ryugu ndi ma chondrite a CI.
Pogwiritsa ntchito njira zogwirizanitsa za microanalysis (Chithunzi Chowonjezera 3), tinayang'ana momwe organic carbon imagawidwira pamalo onse pamwamba pa ion beam fraction (FIB) C0068.25 (Zithunzi 3a–f). Kapangidwe kabwino ka X-ray absorption spectra ya carbon (NEXAFS) pafupi ndi m'mphepete mwa gawo C0068.25 kuwonetsa magulu angapo ogwira ntchito - aromatic kapena C=C (285.2 eV), C=O (286.5 eV), CH (287.5 eV) ndi C( =O)O (288.8 eV) - kapangidwe ka graphene sikapezeka pa 291.7 eV (Chithunzi 3a), zomwe zikutanthauza kuti kutentha kwake kuli kotsika. CH peak yolimba (287.5 eV) ya organics ya C0068.25 imasiyana ndi organics yosasungunuka ya carbonaceous chondrites yomwe idaphunziridwa kale ndipo imafanana kwambiri ndi IDP14 ndi tinthu ta cometary tomwe tidapezedwa ndi Stardust mission. Chiwombankhanga champhamvu cha CH pa 287.5 eV ndi chiwombankhanga chofooka kwambiri kapena C=C pa 285.2 eV zikusonyeza kuti mankhwala achilengedwe ali ndi mankhwala ambiri a aliphatic (Chithunzi 3a ndi Chithunzi Chowonjezera 3a). Madera okhala ndi mankhwala ambiri a aliphatic amapezeka m'malo okhala ndi phyllosilicates, komanso m'malo okhala ndi kapangidwe ka kaboni koipa (kapena C=C) (Chithunzi 3c,d). Mosiyana ndi zimenezi, A0037,22 (Chithunzi Chowonjezera 3) chinawonetsa pang'ono kuti madera okhala ndi kaboni wochepa aliphatic anali ndi kaboni wambiri. Mineralogy yapakati pa tirigu awa ili ndi carbonates zambiri, zofanana ndi chondrite CI 16, zomwe zikusonyeza kusintha kwakukulu kwa madzi ochokera (Table Yowonjezera 1). Mikhalidwe ya oxidizing idzalimbikitsa kuchuluka kwa magulu ogwira ntchito a carbonyl ndi carboxyl m'magulu achilengedwe okhudzana ndi carbonates. Kugawa kwa submicron kwa organics ndi kapangidwe ka kaboni wa aliphatic kungakhale kosiyana kwambiri ndi kugawa kwa silicates zokhala ndi zigawo zokhala ndi zigawo zokhala ndi zigawo. Zizindikiro za mankhwala a aliphatic organic ogwirizana ndi phyllosilicate-OH zinapezeka mu meteorite ya Tagish Lake. Deta yolumikizidwa ya microanalytical ikusonyeza kuti zinthu zachilengedwe zokhala ndi mankhwala a aliphatic zitha kukhala zofala mu asteroids yamtundu wa C ndipo zimagwirizana kwambiri ndi phyllosilicates. Chomalizachi chikugwirizana ndi malipoti am'mbuyomu a aliphatic/aromatic CHs mu tinthu ta Ryugu zomwe zawonetsedwa ndi MicroOmega, microscope yapafupi ndi infrared hyperspectral. Funso lofunika komanso losathetsedwa ndilakuti kodi makhalidwe apadera a mankhwala a aliphatic carbon-rich organic ogwirizana ndi phyllosilicates omwe awonedwa mu kafukufukuyu amapezeka pa asteroid Ryugu yokha.
a, NEXAFS carbon spectra yokhazikika mpaka 292 eV m'dera lolemera la aromatic (C=C) (lofiira), m'dera lolemera la aliphatic (lobiriwira), ndi m'matrix (buluu). Mzere wa imvi ndi Murchison 13 insoluble organic spectrum yoyerekeza. au, arbitration unit. b, Scanning transmission X-ray microscopy (STXM) spectral image ya carbon K-edge yosonyeza kuti gawolo likulamulidwa ndi carbon. c, RGB composite plot yokhala ndi aromatic (C=C) rich regions (ofiira), aliphatic rich regions (obiriwira), ndi matrix (buluu). d, organics yokhala ndi aliphatic compounds yochuluka imayikidwa mu coarse-grained phyllosilicate, derali limakulitsidwa kuchokera m'mabokosi oyera okhala ndi madontho mu b ndi c. e, large nanospheres (ng-1) m'derali limakulitsidwa kuchokera m'bokosi loyera lokhala ndi madontho mu b ndi c. Kwa: pyrrhotite. Pn: nickel-chromite. f, Zithunzi za Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS), Hydrogen (1H), Carbon (12C), ndi Nitrogen (12C14N), zithunzi za 12C/1H element ratio, ndi zithunzi za cross δD, δ13C, ndi δ15N isotope - Gawo PG-1: presolar graphite yokhala ndi extreme 13C enrichment (Supplementary Table 4).
Kafukufuku wa kinetic wa kuwonongeka kwa zinthu zachilengedwe mu meteorites a Murchison angapereke chidziwitso chofunikira chokhudza kufalikira kosiyanasiyana kwa zinthu zachilengedwe za aliphatic zomwe zili ndi tirigu wa Ryugu. Kafukufukuyu akuwonetsa kuti ma bond a aliphatic CH mu zinthu zachilengedwe amapitilira kutentha kwakukulu pafupifupi 30°C pa kholo ndi/kapena kusintha ndi ubale wa nthawi ndi kutentha (monga zaka 200 pa 100°C ndi 0°C zaka 100 miliyoni). . Ngati choyambira sichinatenthedwe pa kutentha kwina kwa nthawi yoposa nthawi inayake, kufalikira koyambirira kwa zinthu zachilengedwe za aliphatic zomwe zili ndi phyllosilicate kungasungidwe. Komabe, kusintha kwa madzi a miyala kungapangitse kutanthauzira kumeneku kukhala kovuta, chifukwa A0037 yolemera carbonate sikuwonetsa madera aliwonse a aliphatic olemera kaboni omwe amagwirizanitsidwa ndi phyllosilicate. Kusintha kwa kutentha kochepa kumeneku kukugwirizana ndi kukhalapo kwa cubic feldspar mu tirigu wa Ryugu (Table Supplementary 1) 20.
Gawo C0068.25 (ng-1; Zithunzi 3a–c,e) lili ndi nanosphere yayikulu yomwe ikuwonetsa aromatic kwambiri (kapena C=C), aliphatic pang'ono, komanso ma spectra ofooka a C(=O)O ndi C=O. . Chizindikiro cha aliphatic carbon sichikugwirizana ndi chizindikiro cha bulk insoluble organics ndi organic nanospheres zogwirizana ndi chondrites (Chithunzi 3a) 17,21. Kusanthula kwa Raman ndi infrared spectroscopic kwa nanospheres mu Lake Tagish kunawonetsa kuti zimapangidwa ndi aliphatic ndi oxidized organic compounds ndi disordered polycyclic aromatic organic compounds ndi complexed composition22,23. Chifukwa chakuti matrix yozungulira ili ndi organics yokhala ndi aliphatic compounds, chizindikiro cha aliphatic carbon mu ng-1 chikhoza kukhala chinthu chowunikira. Chosangalatsa n'chakuti, ng-1 ili ndi silicates amorphous (Chithunzi 3e), kapangidwe kamene sikananenedwebe za organics zilizonse zakunja kwa dziko lapansi. Ma silicate a Amorphous akhoza kukhala zigawo zachilengedwe za ng-1 kapena chifukwa cha kusintha kwa ma silicate amadzi/anhydrous ndi ion ndi/kapena electron beam panthawi yowunika.
Zithunzi za NanoSIMS ion za gawo la C0068.25 (Chithunzi 3f) zikuwonetsa kusintha kofanana mu δ13C ndi δ15N, kupatula tirigu wa presolar wokhala ndi 13C yowonjezera 30,811‰ (PG-1 pachithunzi cha δ13C mu Chithunzi 3f) (Table Yowonjezera 4). Zithunzi za tirigu wa X-ray ndi zithunzi za TEM zapamwamba zimangowonetsa kuchuluka kwa kaboni ndi mtunda pakati pa mapulaneti oyambira a 0.3 nm, womwe umagwirizana ndi graphite. Ndikofunikira kudziwa kuti ma values ​​​​a δD (841 ± 394‰) ndi δ15N (169 ± 95‰), olemera mu aliphatic organic matter yogwirizana ndi coarse-grained phyllosilicates, amakhala okwera pang'ono kuposa avareji ya dera lonse la C (δD = 528 ± 139‰). ‰, δ15N = 67 ± 15 ‰) mu C0068.25 (Table Yowonjezera 4). Izi zikusonyeza kuti zinthu zachilengedwe zokhala ndi aliphatic zambiri mu phyllosilicates zokhala ndi coarse grained zitha kukhala zakale kwambiri kuposa zinthu zachilengedwe zozungulira, popeza izi zitha kukhala kuti zidasinthana isotopic ndi madzi ozungulira m'thupi loyambirira. Kapenanso, kusintha kwa isotopic kumeneku kungagwirizanenso ndi njira yoyambirira yopangira. Amatanthauziridwa kuti ma silicates opyapyala mu CI chondrites adapangidwa chifukwa cha kusintha kosalekeza kwa magulu oyambira a silicate omwe ali ndi coarse grained. Zinthu zachilengedwe zokhala ndi aliphatic zambiri zitha kukhala zitapangidwa kuchokera ku mamolekyu oyambira mu protoplanetary disk kapena interstellar medium isanapangidwe dongosolo la dzuwa, kenako zidasinthidwa pang'ono panthawi ya kusintha kwa madzi kwa thupi la kholo la Ryugu (lalikulu). Kukula (<1.0 km) kwa Ryugu ndi kochepa kwambiri kuti kusunge kutentha kwamkati mokwanira kuti madzi asinthe kuti apange mchere wamadzi25. Kukula (<1.0 km) kwa Ryugu ndi kochepa kwambiri kuti kusunge kutentha kwamkati kokwanira kuti madzi asinthe kuti apange mchere wamadzi25. Размер (<1,0 км) Рюгу слишком мал, чтобы поддерживать достаточное внутреннее тепло для водного изменения с образованием водных. Kukula (<1.0 km) Ryugu ndi yaying'ono kwambiri moti singathe kusunga kutentha kokwanira mkati kuti madzi asinthe kupanga mchere wa m'madzi25. Ryugu 的尺寸（<1.0 公里）太小，不足以维持内部热量以进行水蚀变形成含水矿物25. Ryugu 的尺寸（<1.0 公里）太小，不足以维持内部热量以进行水蚀变形成含水矿物25. Размер Рюгу (<1,0 км) слишком мал, чтобы поддерживать внутреннее тепло для изменения воды с образованием водных минералов25. Kukula kwa Ryugu (<1.0 km) ndi kochepa kwambiri kuti kuthandizire kutentha kwamkati kuti kusinthe madzi kuti apange mchere wamadzi25.Chifukwa chake, ma Ryugu omwe adatsogolera angafunike makilomita makumi ambiri. Zinthu zachilengedwe zokhala ndi mankhwala a aliphatic zimatha kusunga ma isotope ratios awo oyambirira chifukwa chogwirizana ndi ma phyllosilicates okhwima. Komabe, mtundu weniweni wa zonyamula zolemera za isotopic sunadziwikebe chifukwa cha kusakanikirana kovuta komanso kosalala kwa zigawo zosiyanasiyana mu FIB fractions izi. Izi zitha kukhala zinthu zachilengedwe zokhala ndi mankhwala a aliphatic mu ma granules a Ryugu kapena ma phyllosilicates okhwima ozungulira iwo. Dziwani kuti zinthu zachilengedwe pafupifupi mu ma chondrites onse a carbonaceous (kuphatikiza ma chondrites a CI) nthawi zambiri zimakhala zolemera mu D kuposa ma phyllosilicates, kupatula CM Paris 24, 26 meteorites.
Ma plots a voliyumu δD ndi δ15N a zidutswa za FIB zomwe zapezeka pa A0002.23 ndi A0002.26, A0037.22 ndi A0037.23 ndi C0068.23, C0068.25 ndi C0068.26 FIB slices (zonse slices 7 za FIB kuchokera ku tinthu ta Ryugu titatu) Kuyerekeza kwa NanoSIMS ndi zinthu zina za solar system kwawonetsedwa pa chithunzi 4 (Table Supplementary 4)27,28. Kusintha kwa voliyumu mu δD ndi δ15N mu ma profiles a A0002, A0037, ndi C0068 kukugwirizana ndi zomwe zili mu IDP, koma ndizokwera kuposa ma chondrites a CM ndi CI (Chithunzi 4). Dziwani kuti mitundu ya δD ya chitsanzo cha Comet 29 (-240 mpaka 1655‰) ndi yayikulu kuposa ya Ryugu. Ma voliyumu δD ndi δ15N a ma profiles a Ryukyu, nthawi zambiri, ndi ochepa kuposa avareji ya ma comet a banja la Jupiter ndi mtambo wa Oort (Chithunzi 4). Ma δD otsika a ma chondrites a CI angasonyeze mphamvu ya kuipitsidwa kwa dziko lapansi m'zitsanzozi. Popeza kufanana pakati pa Bells, Lake Tagish, ndi IDP, kusiyana kwakukulu kwa ma δD ndi δN mu tinthu ta Ryugu kungasonyeze kusintha kwa zizindikiro zoyambirira za isotopic za zinthu zachilengedwe ndi zamadzi m'dongosolo loyambirira la dzuwa. Kusintha kofanana kwa isotopic mu δD ndi δN mu tinthu ta Ryugu ndi IDP kumasonyeza kuti zonsezi zitha kupangidwa kuchokera kuzinthu zomwezo. Amakhulupirira kuti ma IDP amachokera ku magwero a cometary 14. Chifukwa chake, Ryugu ikhoza kukhala ndi zinthu zofanana ndi comet ndi/kapena dongosolo lakunja la dzuwa. Komabe, izi zitha kukhala zovuta kuposa momwe tikunenera pano chifukwa cha (1) kusakaniza kwa madzi olemera a spherulitic ndi D pa thupi la kholo 31 ndi (2) chiŵerengero cha D/H cha comet monga ntchito ya cometary 32. Komabe, zifukwa za kusiyana kwa ma isotope a hydrogen ndi nitrogen mu tinthu ta Ryugu sizikumveka bwino, pang'ono chifukwa cha kuchuluka kochepa kwa kusanthula komwe kulipo masiku ano. Zotsatira za machitidwe a isotope a hydrogen ndi nitrogen zikuwonjezera kuthekera kwakuti Ryugu ili ndi zinthu zambiri kuchokera kunja kwa Solar System ndipo motero zingasonyeze kufanana kwina ndi ma comets. Mbiri ya Ryugu sinawonetse mgwirizano wowonekera pakati pa δ13C ndi δ15N (Table Supplementary 4).
Kapangidwe ka isotopi ka H ndi N ka tinthu ta Ryugu (mabwalo ofiira: A0002, A0037; mabwalo abuluu: C0068) kamagwirizana ndi kukula kwa dzuwa 27, banja la Jupiter (JFC27), ndi ma comets a cloud a Oort (OCC27), IDP28, ndi ma chondrules a carbonaceous. Kuyerekeza kwa meteorite 27 (CI, CM, CR, C2-ung). Kapangidwe ka isotopi kaperekedwa mu Supplementary Table 4. Mizere yokhala ndi madontho ndi ma isotopi apadziko lapansi a H ndi N.
Kutengera kwa zinthu zosinthasintha (monga zinthu zachilengedwe ndi madzi) ku Dziko Lapansi kukupitirira kukhala vuto26,27,33. Zinthu zachilengedwe za submicron zomwe zimagwirizanitsidwa ndi zinthu zosungunuka mu tinthu ta Ryugu zomwe zapezeka mu kafukufukuyu zitha kukhala gwero lofunika la zinthu zosungunuka. Zinthu zachilengedwe mu zinthu zosungunuka zimatetezedwa bwino ku kuwonongeka16,34 ndi kuwola35 kuposa zinthu zachilengedwe mu matrices opyapyala. Kapangidwe kolemera ka isotopi ka haidrojeni mu tinthu timeneti kumatanthauza kuti sizingakhale gwero lokhalo la zinthu zosungunuka zomwe zimatengedwa kupita ku Dziko Lapansi koyambirira. Zitha kusakanikirana ndi zigawo zomwe zili ndi kapangidwe kopepuka ka haidrojeni isotopic, monga momwe zanenedwera posachedwapa mu lingaliro la kukhalapo kwa madzi oyendetsedwa ndi mphepo mu zinthu zosungunuka.
Mu kafukufukuyu, tikuwonetsa kuti ma meteorite a CI, ngakhale kuti ndi ofunika kwambiri pa geochemical monga oimira kapangidwe kake ka dzuwa, 6,10 ndi zitsanzo zoipitsidwa padziko lapansi. Timaperekanso umboni wolunjika wa kuyanjana pakati pa zinthu zachilengedwe zambiri za aliphatic ndi mchere wamadzi woyandikana nawo ndipo tikuwonetsa kuti Ryugu ikhoza kukhala ndi zinthu zina zakunja kwa dzuwa37. Zotsatira za kafukufukuyu zikuwonetsa bwino kufunika kotenga zitsanzo za protoasteroids mwachindunji komanso kufunikira konyamula zitsanzo zobwezedwa pansi pa mikhalidwe yopanda kanthu komanso yoyera. Umboni womwe waperekedwa pano ukuwonetsa kuti tinthu ta Ryugu mosakayikira ndi chimodzi mwa zinthu zosaipitsidwa kwambiri zomwe zimapezeka kuti zifufuzidwe m'ma laboratories, ndipo kuphunzira kwina kwa zitsanzo zamtengo wapatalizi mosakayikira kudzakulitsa kumvetsetsa kwathu kwa njira zoyambirira za dzuwa. Tinthu ta Ryugu ndi tomwe timayimira bwino kwambiri kapangidwe ka dzuwa.
Kuti tidziwe kapangidwe kake ka zinthu zazing'ono komanso ka mankhwala ka zitsanzo za submicron scale, tinagwiritsa ntchito synchrotron radiation-based computed tomography (SR-XCT) ndi SR X-ray diffraction (XRD)-CT, FIB-STXM-NEXAFS-NanoSIMS-TEM analysis. Palibe kuwonongeka, kuipitsidwa chifukwa cha mlengalenga wa dziko lapansi, komanso palibe kuwonongeka kwa tinthu tating'onoting'ono kapena zitsanzo zamakina. Pakadali pano, tachita kusanthula kwadongosolo kwa volumetric pogwiritsa ntchito scanning electron microscopy (SEM)-EDS, EPMA, XRD, instrumental neutron activation analysis (INAA), ndi laser oxygen isotope fluorination equipment. Njira zoyesera zikuwonetsedwa mu Supplementary Picture 3 ndipo kuyesa kulikonse kwafotokozedwa m'magawo otsatirawa.
Tinthu tating'onoting'ono ta Ryugu tapezeka kuchokera ku gawo lolowera la Hayabusa-2 ndikuperekedwa ku JAXA Control Center ku Sagamihara, Japan, popanda kuipitsa mlengalenga wa Dziko Lapansi4. Mukamaliza kusanthula koyamba komanso kosawononga pamalo omwe JAXA imayang'anira, gwiritsani ntchito zotengera zotsekera pakati pa malo ndi matumba a kapisozi (10 kapena 15 mm m'mimba mwake a safiro ndi chitsulo chosapanga dzimbiri, kutengera kukula kwa chitsanzo) kuti mupewe kusokoneza chilengedwe. chilengedwe, y ndi/kapena zodetsa zapansi (monga nthunzi yamadzi, ma hydrocarbon, mpweya wamlengalenga ndi tinthu tating'onoting'ono) komanso kuipitsidwa pakati pa zitsanzo panthawi yokonzekera ndi kunyamula zitsanzo pakati pa mabungwe ndi mayunivesite38. Pofuna kupewa kuwonongeka ndi kuipitsidwa chifukwa cha kuyanjana ndi mlengalenga wa dziko lapansi (nthunzi ya madzi ndi mpweya), mitundu yonse ya kukonzekera zitsanzo (kuphatikizapo kudula ndi tantalum chisel, kugwiritsa ntchito waya wa waya wolinganizidwa (Meiwa Fosis Corporation DWS 3400) ndi kukonza epoxy) kuti zikhazikitsidwe) zidachitika mu bokosi la magolovesi pansi pa N2 yoyera youma (madontho a mame: -80 mpaka -60 °C, O2 ~50-100 ppm). Zinthu zonse zomwe zimagwiritsidwa ntchito pano zimatsukidwa ndi kuphatikiza kwa madzi oyera kwambiri ndi ethanol pogwiritsa ntchito mafunde a ultrasonic a ma frequency osiyanasiyana.
Apa tikuphunzira za zosonkhanitsa za meteorite za National Polar Research Institute (NIPR) za Antarctic Meteorite Research Center (CI: Orgueil, CM2.4: Yamato (Y)-791198, CY: Y-82162 ndi CY: Y 980115).
Pa kusamutsa pakati pa zida za SR-XCT, NanoSIMS, STXM-NEXAFS ndi TEM analysis, tinagwiritsa ntchito chogwirira cha zitsanzo chopyapyala kwambiri chomwe chafotokozedwa m'maphunziro am'mbuyomu38.
Kusanthula kwa SR-XCT kwa zitsanzo za Ryugu kunachitika pogwiritsa ntchito njira ya BL20XU/SPring-8 CT yolumikizidwa. Njira ya CT yolumikizidwa ili ndi njira zosiyanasiyana zoyezera: malo owonera ambiri ndi mawonekedwe otsika (WL) kuti ijambule kapangidwe kake konse ka chitsanzo, malo owonera ochepa ndi mawonekedwe apamwamba (NH) kuti muyeze molondola dera la chitsanzo, chidwi ndi ma x-ray kuti mupeze mawonekedwe a diffraction a voliyumu ya chitsanzo, ndikuchita XRD-CT kuti mupeze chithunzi cha 2D cha magawo a mchere opingasa mu chitsanzo. Dziwani kuti miyeso yonse ikhoza kuchitidwa popanda kugwiritsa ntchito njira yomangidwa kuti muchotse chogwirira cha chitsanzo kuchokera pansi, zomwe zimapangitsa kuti muyezo wolondola wa CT ndi XRD-CT ukhale wolondola. Chowunikira cha WL mode X-ray (BM AA40P; Hamamatsu Photonics) chinali ndi kamera yowonjezera ya 4608 × 4608 pixel metal-oxide-semiconductor (CMOS) (C14120-20P; Hamamatsu Photonics) yokhala ndi scintillator yokhala ndi makulidwe 10 a lutetium aluminum garnet single crystal thickness µm (Lu3Al5O12:Ce) ndi lens yolumikizira. Kukula kwa pixel mu WL mode ndi pafupifupi 0.848 µm. Chifukwa chake, gawo la view (FOV) mu WL mode ndi pafupifupi 6 mm mu offset CT mode. Chowunikira cha NH mode X-ray (BM AA50; Hamamatsu Photonics) chinali ndi scintillator ya gadolinium-aluminium-gallium garnet (Gd3Al2Ga3O12) yokhuthala ya 20 µm, kamera ya CMOS (C11440-22CU) yokhala ndi resolution ya 2048 × 2048 pixels; Hamamatsu Photonics) ndi lenzi ya ×20. Kukula kwa pixel mu NH mode ndi ~0.25 µm ndipo malo owonera ndi ~0.5 mm. Chowunikira cha XRD mode (BM AA60; Hamamatsu Photonics) chinali ndi scintillator yokhala ndi sikirini ya ufa ya P43 (Gd2O2S:Tb) yokhuthala ya 50 µm, kamera ya CMOS ya 2304 × 2304 pixel resolution (C15440-20UP; Hamamatsu Photonics) ndi lenzi yolumikizirana. Chowunikiracho chili ndi kukula kwa pixel kogwira ntchito kwa 19.05 µm ndi malo owonera a 43.9 mm2. Kuti tiwonjezere FOV, tidagwiritsa ntchito njira ya offset CT mu WL mode. Chithunzi chowunikira chotumizidwa kuti chikonzedwenso cha CT chimakhala ndi chithunzi chomwe chili pakati pa 180° ndi 360° chomwe chimawonetsedwa mozungulira mozungulira mzere wozungulira, ndi chithunzi chomwe chili pakati pa 0° ndi 180°.
Mu XRD mode, kuwala kwa X-ray kumayikidwa ndi mbale ya Fresnel zone. Mu mode iyi, chowunikira chimayikidwa 110 mm kumbuyo kwa chitsanzo ndipo choyimira cha beam chili 3 mm patsogolo pa chowunikira. Zithunzi za diffraction mu 2θ zimayambira 1.43° mpaka 18.00° (grating pitch d = 16.6–1.32 Å) zidapezeka ndi malo a X-ray omwe adayang'aniridwa pansi pa malo owonera a chowunikira. Chitsanzocho chimayenda molunjika nthawi zonse, ndikutembenuka theka pa sitepe iliyonse yowunikira yolunjika. Ngati tinthu ta mchere tikukwaniritsa mkhalidwe wa Bragg tikamazunguliridwa ndi 180°, n'zotheka kupeza diffraction ya tinthu ta mchere mu ndege yopingasa. Zithunzi za diffraction kenako zidaphatikizidwa kukhala chithunzi chimodzi pa sitepe iliyonse yowunikira yolunjika. Mikhalidwe ya kuyesa kwa SR-XRD-CT ndi yofanana ndi ya kuyesa kwa SR-XRD. Mu XRD-CT mode, chowunikira chimayikidwa 69 mm kumbuyo kwa chitsanzo. Zithunzi za diffraction mu 2θ range zimayambira pa 1.2° mpaka 17.68° (d = 19.73 mpaka 1.35 Å), komwe kuwala kwa X-ray ndi choletsa kuwala zonse zimagwirizana ndi pakati pa malo owonera a detector. Jambulani chitsanzo mopingasa ndikuzungulira chitsanzocho 180°. Zithunzi za SR-XRD-CT zinamangidwanso ndi mphamvu ya mineral ngati ma pixel values. Ndi scan yopingasa, chitsanzocho nthawi zambiri chimaskenwa mu masitepe 500–1000.
Pa zoyeserera zonse, mphamvu ya X-ray inali yokhazikika pa 30 keV, popeza iyi ndi malire otsika a kulowa kwa X-ray m'ma meteorites okhala ndi mainchesi pafupifupi 6 mm. Chiwerengero cha zithunzi zomwe zidapezeka pa miyeso yonse ya CT panthawi yozungulira 180° chinali 1800 (3600 ya pulogalamu ya offset CT), ndipo nthawi yowonekera pazithunzi inali 100 ms ya WL mode, 300 ms ya NH mode, 500 ms ya XRD, ndi 50 ms ya XRD-CT ms. Nthawi yodziwika bwino yojambulira zitsanzo ndi pafupifupi mphindi 10 mu WL mode, mphindi 15 mu NH mode, maola atatu a XRD, ndi maola 8 a SR-XRD-CT.
Zithunzi za CT zinamangidwanso pogwiritsa ntchito convolutional back projection ndipo zinasinthidwa kuti zikhale ndi mzere wocheperako wa attenuation coefficient kuyambira 0 mpaka 80 cm-1. Pulogalamu ya Slice idagwiritsidwa ntchito pofufuza deta ya 3D ndipo pulogalamu ya muXRD idagwiritsidwa ntchito pofufuza deta ya XRD.
Tinthu ta Ryugu tokhazikika mu epoxy (A0029, A0037, C0009, C0014 ndi C0068) tinapukutidwa pang'onopang'ono pamwamba mpaka kufika pa mulingo wa filimu yolumikizira ya diamondi ya 0.5 µm (3M) pansi pa nyengo youma, kupewa kuti zinthuzo zisakhudze pamwamba panthawi yopukutidwa. Malo opukutidwa a chitsanzo chilichonse choyamba ankawunikidwa ndi microscopy yopepuka kenako ma electron osweka kuti apeze zithunzi za mineralogy ndi kapangidwe kake (BSE) za zitsanzo ndi zinthu za NIPR zoyenerera pogwiritsa ntchito chithunzi cha JEOL JSM-7100F SEM chokhala ndi chithunzi cha energy dispersive spectrometer (AZtec). Pa chitsanzo chilichonse, zomwe zili mu zinthu zazikulu ndi zazing'ono zinasanthulidwa pogwiritsa ntchito electron probe microanalyzer (EPMA, JEOL JXA-8200). Unikani tinthu ta phyllosilicate ndi carbonate pa 5 nA, miyezo yachilengedwe ndi yopangidwa pa 15 keV, sulfides, magnetite, olivine, ndi pyroxene pa 30 nA. Magiredi a modal adawerengedwa kuchokera ku mapu a zinthu ndi zithunzi za BSE pogwiritsa ntchito pulogalamu ya ImageJ 1.53 yokhala ndi malire oyenera omwe adakhazikitsidwa mwachisawawa pa mchere uliwonse.
Kusanthula kwa isotope ya okosijeni kunachitika ku Open University (Milton Keynes, UK) pogwiritsa ntchito njira ya infrared laser fluorination. Zitsanzo za Hayabusa2 zinaperekedwa ku Open University 38 m'zidebe zodzaza ndi nayitrogeni kuti zisamutsidwe pakati pa malo.
Kuyika zitsanzo kunachitika m'bokosi la magolovesi a nayitrogeni lomwe lili ndi mpweya wochepa wa oxygen pansi pa 0.1%. Pa ntchito yowunikira ya Hayabusa2, chogwirira chatsopano cha chitsanzo cha Ni chinapangidwa, chokhala ndi mabowo awiri okha (m'mimba mwake 2.5 mm, kuya 5 mm), chimodzi cha tinthu ta Hayabusa2 ndi china cha muyezo wamkati wa obsidian. Pakusanthula, chitsime cha chitsanzo chomwe chinali ndi zinthu za Hayabusa2 chinaphimbidwa ndi zenera lamkati la BaF2 pafupifupi 1 mm makulidwe ndi 3 mm m'mimba mwake kuti chigwire chitsanzo panthawi ya laser reaction. Kuyenda kwa BrF5 kupita ku chitsanzocho kunasungidwa ndi njira yosakaniza mpweya yomwe inadulidwa mu chogwirira cha chitsanzo cha Ni. Chipinda cha chitsanzocho chinakonzedwanso kuti chichotsedwe pamzere wa vacuum fluorination kenako nkutsegulidwa m'bokosi la magolovesi lodzaza ndi nayitrogeni. Chipinda cha zidutswa ziwiri chinatsekedwa ndi chisindikizo cha compression cha mkuwa ndi cholumikizira cha EVAC Quick Release CeFIX 38. Zenera la BaF2 la makulidwe a 3 mm pamwamba pa chipindacho limalola kuwona nthawi yomweyo chitsanzocho ndi kutentha kwa laser. Mukamaliza kuyika chitsanzocho, gwiraninso chipindacho ndikuchilumikizanso ku mzere wothira fluorine. Asanachiwunike, chipinda chothira chitsanzocho chinkatenthedwa ndi vacuum mpaka pafupifupi 95°C usiku wonse kuti chichotse chinyezi chilichonse chomwe chimayatsidwa. Pambuyo potenthedwa usiku wonse, chipindacho chinkaloledwa kuzizira kutentha kwa chipinda kenako gawo lomwe linawonekera mumlengalenga panthawi yotumiza chitsanzocho linatsukidwa ndi ma aliquot atatu a BrF5 kuti achotse chinyezi. Njirazi zimaonetsetsa kuti chitsanzo cha Hayabusa 2 sichinawonekere mumlengalenga ndipo sichinaipitsidwe ndi chinyezi kuchokera ku gawo la mzere wothira fluorine womwe umatuluka mumlengalenga panthawi yoyika chitsanzo.
Zitsanzo za tinthu ta Ryugu C0014-4 ndi Orgueil (CI) zinasanthulidwa mu "single" mode42 yosinthidwa, pomwe kusanthula kwa Y-82162 (CY) kunachitika pa thireyi imodzi yokhala ndi zitsime zingapo za zitsanzo41. Chifukwa cha kapangidwe kake ka anhydrous, sikofunikira kugwiritsa ntchito njira imodzi ya CY chondrites. Zitsanzozo zinatenthedwa pogwiritsa ntchito mphamvu ya Photon Machines Inc. infrared CO2 laser. ya 50 W (10.6 µm) yoyikidwa pa gantry ya XYZ pamaso pa BrF5. Makina ojambulira omwe adamangidwa mkati amawunika momwe zinthu zikuyendera. Pambuyo pa fluorination, O2 yotulutsidwayo inatsukidwa pogwiritsa ntchito mipiringidzo iwiri ya cryogenic nitrogen ndi bed yotentha ya KBr kuti ichotse fluorine yochulukirapo. Kapangidwe ka isotopic ka okosijeni woyeretsedwa kanasanthulidwa pa Thermo Fisher MAT 253 dual-channel mass spectrometer yokhala ndi mass resolution ya pafupifupi 200.
Nthawi zina, kuchuluka kwa mpweya wa O2 womwe unatulutsidwa panthawi ya yankho la chitsanzocho kunali kochepera 140 µg, komwe ndi malire oyerekeza ogwiritsira ntchito chipangizo choyezera pa MAT 253 mass spectrometer. Pazochitikazi, gwiritsani ntchito ma microvolumes kuti muwunike. Pambuyo pofufuza tinthu ta Hayabusa2, muyezo wamkati wa obsidian unasinthidwa kukhala fluorinated ndipo kapangidwe kake ka oxygen isotope kanadziwika.
Ma ioni a chidutswa cha NF+ NF3+ amasokoneza kuwala kwa 33 (16O17O). Pofuna kuthetsa vutoli, zitsanzo zambiri zimakonzedwa pogwiritsa ntchito njira zolekanitsira cryogenic. Izi zitha kuchitika kutsogolo musanayese kusanthula kwa MAT 253 kapena ngati kusanthula kwachiwiri pobwezeretsa mpweya wowunikidwa ku sieve yapadera ya molekyulu ndikuwuperekanso pambuyo pa kulekanitsa cryogenic. Kulekanitsa cryogenic kumaphatikizapo kupereka mpweya ku sieve ya molekyulu kutentha kwa nayitrogeni yamadzimadzi kenako nkuwutulutsa mu sieve yoyamba ya molekyulu kutentha kwa -130°C. Kuyesa kwakukulu kwawonetsa kuti NF+ imakhalabe pa sieve yoyamba ya molekyulu ndipo palibe kugawikana kwakukulu komwe kumachitika pogwiritsa ntchito njira iyi.
Kutengera kusanthula mobwerezabwereza kwa miyezo yathu yamkati ya obsidian, kulondola konse kwa dongosololi mu bellows mode ndi: ±0.053‰ ya δ17O, ±0.095‰ ya δ18O, ±0.018‰ ya Δ17O (2 sd). Kusanthula kwa isotope ya okosijeni kumaperekedwa mu notation yokhazikika ya delta, pomwe delta18O imawerengedwa motere:
Gwiritsaninso ntchito chiŵerengero cha 17O/16O cha δ17O. VSMOW ndiye muyezo wapadziko lonse wa Vienna Mean Sea Water Standard. Δ17O ikuyimira kupatuka kuchokera ku mzere wogawa nthaka, ndipo njira yowerengera ndi iyi: Δ17O = δ17O – 0.52 × δ18O. Deta yonse yomwe yaperekedwa mu Supplementary Table 3 yasinthidwa ndi mipata.
Zigawo pafupifupi 150 mpaka 200 nm zokhuthala zinachotsedwa ku tinthu ta Ryugu pogwiritsa ntchito chipangizo cha Hitachi High Tech SMI4050 FIB ku JAMSTEC, Kochi Core Sampling Institute. Dziwani kuti zigawo zonse za FIB zinapezeka kuchokera ku zidutswa zosakonzedwa za tinthu tating'onoting'ono tomwe sitinakonzedwe pambuyo poti zachotsedwa m'zombo zodzaza ndi mpweya wa N2 kuti zisamutsidwe. Zigawo izi sizinayesedwe ndi SR-CT, koma zinakonzedwa popanda kuwonetsedwa kwambiri ku mlengalenga wa dziko lapansi kuti zipewe kuwonongeka ndi kuipitsidwa komwe kungakhudze carbon K-edge spectrum. Pambuyo poika tungsten protective layer, dera lofunika (mpaka 25 × 25 μm2) linadulidwa ndikuchepetsedwa ndi Ga+ ion beam pamagetsi othamanga a 30 kV, kenako pa 5 kV ndi probe current ya 40 pA kuti achepetse kuwonongeka kwa pamwamba. Zigawo zoonda kwambiri kenako zinayikidwa pa ukonde wokulirapo wamkuwa (Kochi mesh) 39 pogwiritsa ntchito micromanipulator yokhala ndi FIB.
Ma pellets a Ryugu A0098 (1.6303mg) ndi C0068 (0.6483mg) adatsekedwa kawiri m'mapepala oyera a polyethylene oyera bwino m'bokosi lodzaza ndi nayitrogeni pa SPring-8 popanda kukhudzana ndi mlengalenga wa dziko lapansi. Kukonzekera zitsanzo za JB-1 (mwala wofotokozera za geological womwe unaperekedwa ndi Geological Survey of Japan) kunachitika ku Tokyo Metropolitan University.
INAA imachitikira ku Institute for Integrated Radiation and Nuclear Sciences, Kyoto University. Zitsanzozo zinawotchedwa kawiri ndi ma radiation cycles osiyanasiyana osankhidwa malinga ndi theka la moyo wa nuclide yomwe imagwiritsidwa ntchito poyesa kuchuluka kwa zinthu. Choyamba, chitsanzocho chinawotchedwa mu pneumatic irradiation chubu kwa masekondi 30. Ma fluxes a ma neutroni otentha komanso othamanga mu chithunzi 3 ndi 4.6 × 1012 ndi 9.6 × 1011 cm-2 s-1, motsatana, kuti adziwe zomwe zili mu Mg, Al, Ca, Ti, V ndi Mn. Mankhwala monga MgO (99.99% purity, Soekawa Chemical), Al (99.9% purity, Soekawa Chemical), ndi Si metal (99.999% purity, FUJIFILM Wako Pure Chemical) nawonso anawotchedwa kuti akonze zinthu zosokoneza nyukiliya monga (n, n). Chitsanzocho chinawotchedwanso ndi sodium chloride (99.99% purity; MANAC) kuti chikonze kusintha kwa neutron flux.
Pambuyo pa kuwala kwa neutron, pepala lakunja la polyethylene linasinthidwa ndi latsopano, ndipo kuwala kwa gamma komwe kunatulutsidwa ndi chitsanzocho ndi reference kunayesedwa nthawi yomweyo ndi chowunikira cha Ge. Zitsanzo zomwezo zinawotchedwanso kwa maola 4 mu chubu chowunikira cha pneumatic. 2 ili ndi ma neutron fluxes otentha komanso othamanga a 5.6 1012 ndi 1.2 1012 cm-2 s-1, motsatana, kuti azindikire Na, K, Ca, Sc, Cr, Fe, Co, Ni, Zn, Ga, As, Content Se, Sb, Os, Ir ndi Au. Zitsanzo zowongolera za Ga, As, Se, Sb, Os, Ir, ndi Au zinawotchedwa pogwiritsa ntchito kuchuluka koyenera (kuyambira 10 mpaka 50 μg) kwa mayankho okhazikika a kuchuluka kodziwika kwa zinthuzi pazidutswa ziwiri za pepala losefera, kutsatiridwa ndi kuwala kwa zitsanzozo. Kuwerengera kwa kuwala kwa gamma kunachitika ku Institute of Integrated Radiation and Nuclear Sciences, Kyoto University ndi RI Research Center, Tokyo Metropolitan University. Njira zowunikira ndi zida zofotokozera kuchuluka kwa zinthu za INAA ndi zofanana ndi zomwe zafotokozedwa m'ntchito yathu yapitayi.
Chipangizo choyezera kuwala cha X-ray (Rigaku SmartLab) chinagwiritsidwa ntchito kusonkhanitsa mitundu ya ma diffraction a zitsanzo za Ryugu A0029 (<1 mg), A0037 (≪1 mg) ndi C0087 (<1 mg) ku NIPR. Chipangizo choyezera kuwala cha X-ray (Rigaku SmartLab) chinagwiritsidwa ntchito kusonkhanitsa mitundu ya ma diffraction a zitsanzo za Ryugu A0029 (<1 mg), A0037 (≪1 mg) ndi C0087 (<1 mg) ku NIPR. Рентгеновский дифрактометр (Rigaku SmartLab) использовали для сбора дифракционных картин образцов Ryugu A0029 (<1 мг), A0037 (≪17m) NIPR. Choyezera kuwala cha X-ray (Rigaku SmartLab) chinagwiritsidwa ntchito kusonkhanitsa zitsanzo za Ryugu A0029 (<1 mg), A0037 (≪1 mg), ndi C0087 (<1 mg) mu NIPR.使用X 射线衍射仪(Rigaku SmartLab) 在NIPR 收集Ryugu 样品A0029 (<1 mg)、A0037 (<1 mg) 和C0087 (<1 mg) 的衍射图案.使用X 射线衍射仪(Rigaku SmartLab) 在NIPR 收集Ryugu 样品A0029 (<1 mg)、A0037 (<1 mg) 和C0087 (<1 mg) 的衍射图案. Дифрактограммы образцов Ryugu A0029 (<1 мг), A0037 (<1 мг) ndi C0087 (<1 мг) были получены в NIPR с использованием рентгеновгенгей ренгенов ренгенов ренгенов рабованием рентгеновся в NIPR. Zitsanzo za Ryugu A0029 (<1 mg), A0037 (<1 mg) ndi C0087 (<1 mg) zinapezeka ku NIPR pogwiritsa ntchito X-ray diffractometer (Rigaku SmartLab).Zitsanzo zonse zinaphwanyidwa kukhala ufa wosalala pa wafer ya silicon yosawala pogwiritsa ntchito mbale ya galasi ya safiro kenako n’kufalikira mofanana pa wafer ya silicon yosawala popanda madzi (madzi kapena mowa). Miyezo yake ndi iyi: Cu Kα X-ray imapangidwa pa voteji ya chubu ya 40 kV ndi mphamvu ya chubu ya 40 mA, kutalika kwa mpata wocheperako ndi 10 mm, ngodya yosiyana ndi (1/6)°, liwiro lozungulira mkati ndi 20 rpm, ndipo kutalika kwake ndi 2θ (ngodya ya Bragg iwiri) ndi 3-100° ndipo zimatenga pafupifupi maola 28 kuti zifufuzidwe. Bragg Brentano optics inagwiritsidwa ntchito. Chowunikira ndi chowunikira cha silicon semiconductor cha dimensional imodzi (D/teX Ultra 250). Ma X-ray a Cu Kβ anachotsedwa pogwiritsa ntchito fyuluta ya Ni. Pogwiritsa ntchito zitsanzo zomwe zilipo, muyeso wa magnesian saponite yopangidwa (JCSS-3501, Kunimine Industries CO. Ltd), serpentine (leaf serpentine, Miyazu, Nikka) ndi pyrrhotite (monoclinic 4C, Chihua, Mexico Watts) unayerekezeredwa kuti uzindikire ma peaks ndikugwiritsa ntchito deta ya diffraction ya fayilo ya ufa kuchokera ku International Center for Diffraction Data, dolomite (PDF 01-071-1662) ndi magnetite (PDF 00-019-0629). Deta ya diffraction kuchokera ku Ryugu inayerekezeredwanso ndi deta ya hydroaltered carbonaceous chondrites, Orgueil CI, Y-791198 CM2.4, ndi Y 980115 CY (heating stage III, 500–750°C). Kuyerekezako kunawonetsa kufanana ndi Orgueil, koma osati ndi Y-791198 ndi Y 980115.
Ma spectra a NEXAFS okhala ndi m'mphepete mwa kaboni K a zigawo zoonda kwambiri za zitsanzo zopangidwa kuchokera ku FIB adayesedwa pogwiritsa ntchito njira ya STXM BL4U ku UVSOR synchrotron facility ku Institute of Molecular Sciences (Okazaki, Japan). Kukula kwa dothi la beam yoyang'ana bwino ndi mbale ya Fresnel zone ndi pafupifupi 50 nm. Gawo la mphamvu ndi 0.1 eV ya kapangidwe kabwino ka dera lapafupi ndi m'mphepete (283.6–292.0 eV) ndi 0.5 eV (280.0–283.5 eV ndi 292.5–300.0 eV) ya madera akutsogolo ndi kumbuyo. Nthawi ya pixel iliyonse ya chithunzi idakhazikitsidwa pa 2 ms. Pambuyo pochoka, chipinda chowunikira cha STXM chidadzazidwa ndi helium pamphamvu ya pafupifupi 20 mbar. Izi zimathandiza kuchepetsa kutentha kwa zida za X-ray optics mu chipinda ndi chosungira zitsanzo, komanso kuchepetsa kuwonongeka kwa zitsanzo ndi/kapena oxidation. Ma spectra a kaboni a NEXAFS K-edge adapangidwa kuchokera ku deta yosungidwa pogwiritsa ntchito pulogalamu ya aXis2000 ndi pulogalamu yoyendetsera deta ya STXM. Dziwani kuti chikwama chotumizira zitsanzo ndi bokosi la glovebox zimagwiritsidwa ntchito kupewa kuipitsidwa kwa zitsanzo ndi kuipitsidwa.
Pambuyo pa kusanthula kwa STXM-NEXAFS, kapangidwe ka isotopi ka haidrojeni, kaboni, ndi nayitrogeni wa zidutswa za Ryugu FIB kanasanthulidwa pogwiritsa ntchito isotope imaging ndi JAMSTEC NanoSIMS 50L. Mzere woyambira wa Cs+ wa pafupifupi 2 pA wowunikira isotope ya kaboni ndi nayitrogeni ndi pafupifupi 13 pA wowunikira isotope ya hydrogen umayikidwa pamalo a pafupifupi 24 × 24 µm2 mpaka 30 × 30 µm2 pachitsanzo. Pambuyo pa kupopera kwa mphindi zitatu pa mphamvu ya primary beam current yamphamvu, kusanthula kulikonse kunayambitsidwa pambuyo pokhazikika kwa mphamvu ya secondary beam. Pa kusanthula kwa isotope za kaboni ndi nayitrogeni, zithunzi za 12C–, 13C–, 16O–, 12C14N– ndi 12C15N– zinapezedwa nthawi imodzi pogwiritsa ntchito kuzindikira kwa ma electron multiplier multiplex asanu ndi awiri okhala ndi mass resolution pafupifupi 9000, zomwe ndizokwanira kulekanitsa mankhwala onse oyenera a isotopic. Kusokoneza (monga 12C1H pa 13C ndi 13C14N pa 12C15N). Pa kusanthula ma isotope a hydrogen, zithunzi za 1H-, 2D- ndi 12C- zinapezeka ndi resolution ya unyinji wa pafupifupi 3000 ndi kuzindikira kosiyanasiyana pogwiritsa ntchito ma electron multipliers atatu. Kusanthula kulikonse kumakhala ndi zithunzi 30 zojambulidwa za dera lomwelo, ndi chithunzi chimodzi chokhala ndi ma pixel 256 × 256 pakusanthula kwa isotope ya carbon ndi nitrogen ndi ma pixel 128 × 128 pakusanthula kwa isotope ya hydrogen. Nthawi yochedwa ndi 3000 µs pa pixel iliyonse pakusanthula kwa isotope ya carbon ndi nitrogen ndi 5000 µs pa pixel iliyonse pakusanthula kwa isotope ya hydrogen. Tagwiritsa ntchito 1-hydroxybenzotriazole hydrate ngati miyezo ya isotope ya hydrogen, carbon ndi nitrogen kuti tiwongolere kugawa kwa ma instrumental mass45.
Kuti tidziwe kapangidwe ka silicon isotopic ka graphite ya presolar mu FIB C0068-25 profile, tinagwiritsa ntchito ma electron multipliers asanu ndi limodzi okhala ndi ma electron resolution a pafupifupi 9000. Zithunzizo zimakhala ndi ma pixel 256 × 256 okhala ndi nthawi yochedwa ya 3000 µs pa pixel iliyonse. Tinayesa chida chogawa ma ss pogwiritsa ntchito ma silicon wafers ngati miyezo ya hydrogen, carbon, ndi silicon isotope.
Zithunzi za Isotope zinakonzedwa pogwiritsa ntchito pulogalamu ya NASA's NanoSIMS45 imaging. Detayo inakonzedwa kuti ipeze ma electron multiplier dead time (44 ns) ndi quasi-multaneous arrival effects. Kulinganiza kosiyanasiyana kwa scan pa chithunzi chilichonse kuti chikonze kuti chithunzi chiziyenda bwino panthawi yopeza. Chithunzi chomaliza cha isotope chimapangidwa powonjezera ma ayoni achiwiri kuchokera pachithunzi chilichonse pa pixel iliyonse yojambulira.
Pambuyo pa kusanthula kwa STXM-NEXAFS ndi NanoSIMS, magawo omwewo a FIB adawunikidwa pogwiritsa ntchito maikulosikopu ya ma electron otumizira (JEOL JEM-ARM200F) pamagetsi othamanga a 200 kV ku Kochi, JAMSTEC. Kapangidwe ka microstructure kanawonedwa pogwiritsa ntchito TEM yowala komanso TEM yowunikira mbali yayitali m'munda wamdima. Magawo a mchere adazindikirika ndi ma spot electron diffraction ndi lattice band imaging, ndipo kusanthula kwa mankhwala kunachitika ndi EDS ndi 100 mm2 silicon drift detector ndi pulogalamu ya JEOL Analysis Station 4.30. Pa kusanthula kochuluka, mphamvu ya X-ray ya chinthu chilichonse idayesedwa mu TEM scanning mode yokhala ndi nthawi yokhazikika yopezera deta ya 30 s, malo owunikira beam a ​​~100 × 100 nm2, ndi beam current ya 50 pA. Chiŵerengero (Si + Al)-Mg-Fe mu silicates zogawanika chinadziwika pogwiritsa ntchito experimental coefficient k, yokonzedwa kuti iwoneke ngati ndi yokhuthala, yopezeka kuchokera ku standard ya natural pyropagarnet.
Zithunzi zonse ndi kusanthula komwe kwagwiritsidwa ntchito mu kafukufukuyu kukupezeka pa JAXA Data Archives and Communication System (DARTS) https://www.darts.isas.jaxa.jp/curation/hayabusa2. Nkhaniyi ikupereka deta yoyambirira.
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