Kitazato, K.K.KitazatoMilliken, R. E.R. E.MillikenIwata, T.T.IwataAbe, M.M.AbeOhtake, M.M.OhtakeMatsuura, S.S.MatsuuraArai, T.T.AraiNakauchi, Y.Y.NakauchiNakamura, T.T.NakamuraMatsuoka, M.M.MatsuokaSenshu, H.H.SenshuHirata, N.N.HirataHiroi, T.T.HiroiPilorget, C.C.PilorgetBrunetto, R.R.BrunettoPoulet, F.F.PouletRiu, L.L.RiuBibring, J. -P.J. -P.BibringTakir, D.D.TakirDomingue, D. L.D. L.DomingueVilas, F.F.VilasBarucci, M. A.M. A.BarucciPERNA, DavideDavidePERNAPALOMBA, ErnestoErnestoPALOMBAGALIANO, ANNAANNAGALIANOTsumura, K.K.TsumuraOsawa, T.T.OsawaKomatsu, M.M.KomatsuNakato, A.A.NakatoTakato, N.N.TakatoMatsunaga, T.T.MatsunagaTakagi, Y.Y.TakagiMatsumoto, K.K.MatsumotoKouyama, T.T.KouyamaYokota, Y.Y.YokotaTatsumi, E.E.TatsumiSakatani, N.N.SakataniYamamoto, Y.Y.YamamotoOkada, T.T.OkadaSugita, S.S.SugitaHonda, R.R.HondaMorota, T.T.MorotaKameda, S.S.KamedaSawada, H.H.SawadaHonda, C.C.HondaYamada, M.M.YamadaSuzuki, H.H.SuzukiYoshioka, K.K.YoshiokaHayakawa, M.M.HayakawaOgawa, K.K.OgawaCho, Y.Y.ChoShirai, K.K.ShiraiShimaki, Y.Y.ShimakiYamaguchi, A.A.YamaguchiOgawa, N.N.OgawaTerui, F.F.TeruiYamaguchi, T.T.YamaguchiTakei, Y.Y.TakeiSaiki, T.T.SaikiNakazawa, S.S.NakazawaTanaka, S.S.TanakaYoshikawa, M.M.YoshikawaWatanabe, S.S.WatanabeTsuda, Y.Y.Tsuda2021-04-212021-04-2120190036-8075http://hdl.handle.net/20.500.12386/30832The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu’s surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)-bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.STAMPAenArticle10.1126/science.aav74322-s2.0-85064039118https://science.sciencemag.org/content/364/6437/2722019Sci...364..272KFIS/05 - ASTRONOMIA E ASTROFISICA