Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth.
Shogo TachibanaHirotaka SawadaRyuji OkazakiYoshinori TakanoK SakamotoYayoi N MiuraC OkamotoHajime YanoS YamanouchiPatrick MichelYun ZhangStephen R SchwartzF ThuilletHisayoshi YurimotoTomoki NakamuraTakaaki NoguchiHikaru YabutaHiroshi NaraokaAkira TsuchiyamaNaoya ImaeK KurosawaAkiko M NakamuraKazunori OgawaSeiji SugitaTomokatsu MorotaRie HondaShingo KamedaEri TatsumiYuichiro ChoKazuo YoshiokaYasuhiro YokotaMasahiko HayakawaMoe MatsuokaNaoya SakataniManabu YamadaToru KouyamaHidehiko SuzukiChikatoshi HondaT YoshimitsuT KubotaH DemuraToru YadaM NishimuraKasumi YogataAiko NakatoMiwa YoshitakeA I SuzukiShizuho FuruyaKentaro HatakedaAkiko MiyazakiK KumagaiTatsuaki OkadaMasanao AbeTomohiro UsuiTrevor R IrelandMasaki FujimotoT YamadaMasahiko ArakawaHarold C ConnollyAtsushi FujiiSunao HasegawaNaoyuki HirataNaru HirataC HiroseSatoshi HosodaY IijimaHitoshi IkedaMasateru IshiguroYoshiaki IshiharaTakahiro IwataShota KikuchiKohei KitazatoDante S LaurettaGuy LibourelBernard MartyKoji MatsumotoTatsuhiro MichikamiYuya MimasuAkira MiuraO MoriK Nakamura-MessengerNoriyuki NamikiAnn N NguyenLarry R NittlerHirotomo NodaRina NoguchiNaoko OgawaGo OnoMasanobu OzakiHiroki SenshuT ShimadaYuri ShimakiKei ShiraiStefania SoldiniT TakahashiYuto TakeiHiroshi TakeuchiRyudo TsukizakiKoji WadaYukio YamamotoKento YoshikawaK YumotoMichael E ZolenskySatoru NakazawaFuyuto TeruiSatoshi TanakaTakanao SaikiMakoto YoshikawaSei'ichiro WatanabeYuichi TsudaPublished in: Science (New York, N.Y.) (2022)
The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.