On the possible formation of nucleic acids on the early Earth: Derivery of source materials from extraterrestrial environments

• Project/Area Number: 21H04501
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 17:Earth and planetary science and related fields
• Research Institution: Hokkaido University
• Principal Investigator: OBA YASUHIRO 北海道大学, 低温科学研究所, 准教授 (00507535)
• Co-Investigator(Kenkyū-buntansha): 高野 淑識 国立研究開発法人海洋研究開発機構, 海洋機能利用部門(生物地球化学センター), センター長 (80399815)
• Project Period (FY): 2021-04-05 – 2025-03-31
• Project Status: Completed (Fiscal Year 2024)
• Budget Amount: ¥43,160,000 (Direct Cost: ¥33,200,000、Indirect Cost: ¥9,960,000); Fiscal Year 2024: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000); Fiscal Year 2023: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000); Fiscal Year 2022: ¥7,800,000 (Direct Cost: ¥6,000,000、Indirect Cost: ¥1,800,000); Fiscal Year 2021: ¥22,880,000 (Direct Cost: ¥17,600,000、Indirect Cost: ¥5,280,000)
• Keywords: 核酸塩基 / 生命の起源 / 地球外物質 / 小惑星サンプルリターン / 化学進化 / 遺伝情報 / 核酸 / 複素環化合物 / 分子進化

Outline of Research at the Start

本研究では，地球外物質によって原始地球上に供給された分子が原始地球上での生命誕生の材料となったという仮説について，とくに遺伝物質である核酸生成への地球外物質（彗星，炭素質隕石，惑星間塵：いずれも原始地球上への主要な有機物供給源）の寄与を，模擬彗星サンプルと隕石有機物の分析で明らかにする。
彗星に含まれる分子を模擬実験で作製し，反応生成物を模擬彗星サンプルとして扱うこととする。隕石有機物は現有の炭素質隕石から抽出する。
対象化合物は液体もしくはガスクロマトグラフ/質量分析計で分析する。

Outline of Final Research Achievements

The current project aims to clarify a possible contribution of molecules delivered from extraterrestrial environments to the formation of nucleic acids on the early Earth. We analyzed various kinds of carbonaceous meteorites including Murchison and samples returned from carbonaceous asteroids Ryugu and Bennu were analyzed. We found that all canonical nucleobases used in terrestrial biology such as cytosine, uracil, thymine, adenine, and guanine were present in these extraterrestrial materials. The detection of all canonical nucleobases strongly suggests that they should have been present on the early Earth, which may have a possible contribution to the origin of the first life on Earth, as has been expected since early 90's.

Academic Significance and Societal Importance of the Research Achievements

これまでに炭素質隕石から核酸塩基の検出を試みた例はあったが，分析技術がまだ未発達であったため，地球生命に使われる核酸塩基５種の存在は確認されておらず，それら地球外環境で生成した核酸塩基の，地球上での生命の起源への寄与はほとんど期待されていなかった。しかし本研究で明らかにした「真の」核酸塩基分布は従来のそうした考えを一新するものとなり，「地球上での生命の起源」という研究者だけでなく広く一般的にも興味を持たれるテーマについて，大きな進展をもたらすことができた。

Research Products

• [Int'l Joint Research] NASA(米国)
• [Int'l Joint Research] CSIC/INTA(スペイン)
• [Int'l Joint Research] NASA(米国)
• [Int'l Joint Research] グルノーブル大学(フランス)
• [Int'l Joint Research] コロンボ大学(スリランカ)
• [Int'l Joint Research] NASA/NRAO(米国)
• [Int'l Joint Research] グルノーブル大学(フランス)
• [Int'l Joint Research] INAF/ペルージャ大学(イタリア)
• [Int'l Joint Research] ヴィクトリア大学(カナダ)
• [Int'l Joint Research] マックスプランク宇宙物理学研究所(ドイツ)
• [Int'l Joint Research]
• [Journal Article] Compound-Specific Carbon and Nitrogen Isotopic Analyses of Underivatized Pyrimidine and Purine Nucleobases (2025)
  • Author(s): Koga Toshiki、Takano Yoshinori、Ogawa Nanako O.、Hollingsworth Emily H.、Oba Yasuhiro、Ohkouchi Naohiko
  • Journal Title: ACS Earth and Space Chemistry Volume: 9 Issue: 3 Pages: 424-432
  • DOI: 10.1021/acsearthspacechem.4c00110
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Abundant ammonia and nitrogen-rich soluble organic matter in samples from asteroid (101955) Bennu (2025)
  • Author(s): Glavin Daniel P.、Dworkin Jason P.、Yasuhiro Oba (62人中45番目）et al.
  • Journal Title: Nature Astronomy Volume: 9 Issue: 2 Pages: 199-210
  • DOI: 10.1038/s41550-024-02472-9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Hydrogenation of acetaldehyde on interstellar ice analogs results in limited destruction (2025)
  • Author(s): Molpeceres G.、Nguyen T.、Oba Y.、Watanabe N.
  • Journal Title: Astronomy & Astrophysics Volume: 694 Pages: A299-A299
  • DOI: 10.1051/0004-6361/202451990
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Evidence for Jet/Outflow Shocks Heating the Environment around the Class I Protostellar Source Elias 29: FAUST XXI (2025)
  • Author(s): Oya Yoko、Oba Yasuhiro (69人中52番目）et al.
  • Journal Title: The Astrophysical Journal Volume: 980 Issue: 2 Pages: 263-263
  • DOI: 10.3847/1538-4357/adabe7
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] FAUST (2025)
  • Author(s): Hirota T.、Oba Y. (55人中41番目）et al.
  • Journal Title: Astronomy & Astrophysics Volume: 695 Pages: A278-A278
  • DOI: 10.1051/0004-6361/202453386
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] FAUST XIII. Dusty cavity and molecular shock driven by IRS7B in the Corona Australis cluster (2024)
  • Author(s): Sabatini G.,Podio L.,Codella C.,et al.
  • Journal Title: Astronomy & Astrophysics Volume: 684 Pages: L12-L12
  • DOI: 10.1051/0004-6361/202449616
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Enantioselective three-dimensional high-performance liquid chromatographic determination of amino acids in the Hayabusa2 returned samples from the asteroid Ryugu (2024)
  • Author(s): Furusho Aogu、Ishii Chiharu、Akita Takeyuki、Oyaide Mai、Mita Masashi、Hikaru Yabuta(代表者は 55番目)、ほか67名
  • Journal Title: Journal of Chromatography Open Volume: 5 Pages: 100134-100134
  • DOI: 10.1016/j.jcoa.2024.100134
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Multiple chemical tracers finally unveil the intricate NGC?1333 IRAS?4A outflow system. FAUST XVI (2024)
  • Author(s): Chahine Layal、Yasuhiro Oba (57人中44番目）et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 531 Issue: 2 Pages: 2653-2668
  • DOI: 10.1093/mnras/stae1320
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu (2024)
  • Author(s): Takano Yoshinori、Naraoka Hiroshi、Dworkin Jason P.、Koga Toshiki、Sasaki Kazunori、Hikaru Yabuta (代表者は26番目)、ほか37名 4.巻 15
  • Journal Title: Nature Communications Volume: 15 Issue: 1 Pages: 5708-5708
  • DOI: 10.1038/s41467-024-49237-6
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] FAUST (2024)
  • Author(s): Podio L., Oba Y. (58人中45番目)、et al.
  • Journal Title: Astronomy & Astrophysics Volume: 688 Pages: L22-L22
  • DOI: 10.1051/0004-6361/202450742
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Proposed Importance of HOCO Chemistry: Inefficient Formation of CO₂ from CO and OH Reactions on Ice Dust (2024)
  • Author(s): Ishibashi Atsuki、Molpeceres German、Hidaka Hiroshi、Oba Yasuhiro、Lamberts Thanja、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Volume: 976 Issue: 2 Pages: 162-162
  • DOI: 10.3847/1538-4357/ad8235
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Chemical Pathways of SO2 with Hydrogen Atoms on Interstellar Ice Analogues (2024)
  • Author(s): Nguyen Thanh、Oba Yasuhiro、Sameera W. M. C.、Furuya Kenji、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Volume: 976 Issue: 2 Pages: 250-250
  • DOI: 10.3847/1538-4357/ad88ec
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Abundant extraterrestrial purine nucleobases in the Murchison meteorite: Implications for a unified mechanism for purine synthesis in carbonaceous chondrite parent bodies (2024)
  • Author(s): Koga, T., Takano, Y., Oba, Y., Naraoka, H., and Ohkouchi, N.
  • Journal Title: Geochimica et Cosmochimica Acta Volume: 365 Pages: 253-265
  • DOI: 10.1016/j.gca.2023.10.024
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The spatial distribution of soluble organic matter and their relationship to minerals in the asteroid (162173) Ryugu (2023)
  • Author(s): Hashiguchi, Minako; Aoki, Dan; Fukushima, Kazuhiko and 51 more (Yabuta, H.は34番目)
  • Journal Title: Earth, Planets and Space Volume: 75 Issue: 1 Pages: 73-73
  • DOI: 10.1186/s40623-023-01792-w
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Ryugu asteroid sample return provides a natural laboratory for primordial chemical evolution (2023)
  • Author(s): Oba, Y., Takano, Y., Dworkin, J.P., and Naraoka, H.
  • Journal Title: Nature Communications Volume: 14 Issue: 1 Pages: 3107-3107
  • DOI: 10.1038/s41467-023-38518-1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Chemical evolution of primordial salts and organic sulfur molecules in the asteroid 162173 Ryugu (2023)
  • Author(s): Yoshimura, Toshihiro; Takano, Yoshinori; Naraoka, Hiroshi and 84 more (Yabuta, H.は26番目)
  • Journal Title: Nature Communications Volume: 14 Issue: 1 Pages: 5284-5284
  • DOI: 10.1038/s41467-023-40871-0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Determination of the Branching Ratio of CH₃OH + OH Reaction on Water Ice Surface at 10 K (2023)
  • Author(s): Ishibashi Atsuki、Hidaka Hiroshi、Sameera W. M. C.、Oba Yasuhiro、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Volume: 960 Issue: 1 Pages: 90-90
  • DOI: 10.3847/1538-4357/acfb82
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Polycyclic aromatic hydrocarbons in samples of Ryugu formed in the interstellar medium (2023)
  • Author(s): Zeichner S. S., Aponte J. C., Bhattacharjee S., Dong G., Hofmann A. E., ..., Tachibana S., et al
  • Journal Title: Science Volume: 382 Issue: 6677 Pages: 1411-1416
  • DOI: 10.1126/science.adg6304
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Investigating the impact of x‐ray computed tomography imaging on soluble organic matter in the Murchison meteorite: Implications for Bennu sample analyses (2023)
  • Author(s): Glavin, D.P., Eckley, S.A., Aponte, J.C., Berger, E.L., Burton, A.S., Dworkin, J.P., Elsila, J.E., Ferguson, F.T., Furukawa, Y., Graham, H.V., Koga, T., Liss, M., McLain, H.L., Naraoka, H., Oba, Y., Parker, E.T., Righter, K., Schmitt-Kopplin, P., Simkus, D.N., Takano, Y., Connolly, H.C.Jr., and Lauretta, D.S. et al.
  • Journal Title: Meteoritics & Planetary Science Volume: 59 Issue: 1 Pages: 105-133
  • DOI: 10.1111/maps.14111
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Surface Reaction of Methyl Mercaptan (CH₃SH) with Hydrogen Atoms on Amorphous Solid Water (2023)
  • Author(s): Nguyen Thanh、Oba Yasuhiro、Sameera W. M. C.、Furuya Kenji、Kouchi Akira、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Volume: 944 Issue: 2 Pages: 219-219
  • DOI: 10.3847/1538-4357/acafde
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Soluble organic molecules in samples of the carbonaceous asteroid (162173) Ryugu (2023)
  • Author(s): Naraoka Hiroshi、Takano Yoshinori、Dworkin Jason P.、Oba Yasuhiro、Hamase Kenji、Furusho Aogu、Ogawa Nanako O.、Hashiguchi Minako、Fukushima Kazuhiko、Aoki Dan ... Yabuta Hikaru ... et al.
  • Journal Title: Science Volume: 379 Issue: 6634 Pages: 9033-9033
  • DOI: 10.1126/science.abn9033
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Uracil in the carbonaceous asteroid (162173) Ryugu (2023)
  • Author(s): Oba Yasuhiro、Koga Toshiki、Takano Yoshinori、Ogawa Nanako O.、Ohkouchi Naohiko、Sasaki Kazunori、Sato Hajime、Glavin Daniel P.、Dworkin Jason P. ... Yabuta Hikaru ... Hayabusa2-initial-analysis SOM team
  • Journal Title: Nature Communications Volume: 14 Issue: 1 Pages: 1292-1292
  • DOI: 10.1038/s41467-023-36904-3
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Identifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites (2022)
  • Author(s): Oba Yasuhiro、Takano Yoshinori、Furukawa Yoshihiro、Koga Toshiki、Glavin Daniel P.、Dworkin Jason P.、Naraoka Hiroshi
  • Journal Title: Nature Communications Volume: 13 Issue: 1 Pages: 2008-2008
  • DOI: 10.1038/s41467-022-29612-x
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Diffusion Activation Energy and Desorption Activation Energy for Astrochemically Relevant Species on Water Ice Show No Clear Relation (2022)
  • Author(s): Furuya Kenji、Hama Tetsuya、Oba Yasuhiro、Kouchi Akira、Watanabe Naoki、Aikawa Yuri
  • Journal Title: The Astrophysical Journal Letters Volume: 933 Issue: 1 Pages: L16-L16
  • DOI: 10.3847/2041-8213/ac78e9
  • Peer Reviewed / Open Access
• [Journal Article] FAUST V. Hot methanol in the [BHB2007] 11 protobinary system; hot corino versus shock origin (2022)
  • Author(s): Vastel C.、Alves F.、Ceccarelli C.、Bouvier M.、Jimenez-Serra I.、Sakai T.、Caselli P.、Evans L.、Fontani F.、Le Gal R.、Chandler C. J.、Svoboda B.、Maud L.、Codella C.、Sakai N.、Lopez-Sepulcre A.、Moellenbrock G.、Hanawa T.、Yamamoto S. et al.
  • Journal Title: Astronomy & Astrophysics Volume: 664 Pages: A171-A171
  • DOI: 10.1051/0004-6361/202243414
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Maleimide index: a paleo-redox index based on fragmented fossil-chlorophylls obtained by chromic acid oxidation (2022)
  • Author(s): Asahina Kenta、Takahashi Satoshi、Saito Ryosuke、Kaiho Kunio、Oba Yasuhiro
  • Journal Title: RSC Advances Volume: 12 Issue: 48 Pages: 31061-31067
  • DOI: 10.1039/d2ra04702k
  • Peer Reviewed / Open Access
• [Journal Article] Quantifying the Chemical Desorption of H2S and PH from Amorphous Water-ice Surfaces (2022)
  • Author(s): Furuya Kenji、Oba Yasuhiro、Shimonishi Takashi
  • Journal Title: The Astrophysical Journal Volume: 926 Issue: 2 Pages: 171-171
  • DOI: 10.3847/1538-4357/ac4260
  • Peer Reviewed / Open Access
• [Journal Article] Misaligned Rotations of the Envelope, Outflow, and Disks in the Multiple Protostellar System of VLA 1623-2417: FAUST. III (2022)
  • Author(s): Ohashi Satoshi、Codella Claudio、Sakai Nami、et al.
  • Journal Title: The Astrophysical Journal Volume: 927 Issue: 1 Pages: 54-54
  • DOI: 10.3847/1538-4357/ac4cae
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Formation of chiral CO polyhedral crystals on icy interstellar grains (2021)
  • Author(s): Kouchi, A., Tsuge, M., Hama, T., Niinomi, H., Nakatani, N., Shimonishi, T., Oba, Y., Kimura, Y., Sirono, S.-. iti ., Okuzumi, S., Momose, M., Furuya, K., & Watanabe, N.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 505 Issue: 1 Pages: 1530-1542
  • DOI: 10.1093/mnras/stab1173
  • NAID: 120007132042
  • Peer Reviewed / Open Access
• [Journal Article] Transmission Electron Microscopy Study of the Morphology of Ices Composed of H2O, CO2, and CO on Refractory Grains (2021)
  • Author(s): Kouchi, A., Tsuge, M., Hama, T., Oba, Y., Okuzumi, S., Sirono, S.-. iti ., Momose, M., Nakatani, N., Furuya, K., Shimonishi, T., Yamazaki, T., Hidaka, H., Kimura, Y., Murata, K.-. ichiro ., Fujita, K., Nakatsubo, S., Tachibana, S., & Watanabe, N.
  • Journal Title: The Astrophysical Journal Volume: 918 Issue: 2 Pages: 45-45
  • DOI: 10.3847/1538-4357/ac0ae6
  • Peer Reviewed / Open Access
• [Journal Article] Experimental and Computational Studies on the Physicochemical Behavior of Phosphine Induced by Reactions with H and D Atoms on Interstellar Ice Grains (2021)
  • Author(s): Nguyen Thanh、Oba Yasuhiro、Sameera W. M. C.、Kouchi Akira、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Volume: 918 Issue: 2 Pages: 73-73
  • DOI: 10.3847/1538-4357/ac0cf4
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Efficient formation pathway of methyl formate: The role of OH radicals on ice dust (2021)
  • Author(s): Ishibashi Atsuki、Hidaka Hiroshi、Oba Yasuhiro、Kouchi Akira、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Letters Volume: 921 Issue: 1 Pages: L13-L13
  • DOI: 10.3847/2041-8213/ac3005
  • Peer Reviewed / Open Access
• [Journal Article] Successive H-atom Addition to Solid OCS on Compact Amorphous Solid Water (2021)
  • Author(s): Nguyen Thanh、Oba Yasuhiro、Sameera W. M. C.、Kouchi Akira、Watanabe Naoki
  • Journal Title: The Astrophysical Journal Volume: 922 Issue: 2 Pages: 146-146
  • DOI: 10.3847/1538-4357/ac2238
  • Peer Reviewed / Open Access
• [Journal Article] UV-induced formation of ice XI observed using an ultra-high vacuum cryogenic transmission electron microscope and its implications for planetary science (2021)
  • Author(s): Kouchi Akira、Kimura Yuki、Kitajima Kensei、Katsuno Hiroyasu、Hidaka Hiroshi、Oba Yasuhiro、Tsuge Masashi、Yamazaki Tomoya、Fujita Kazuyuki、Hama Tetsuya、Takahashi Yukihiro、Nakatsubo Shunichi、Watanabe Naoki
  • Journal Title: Frontiers in Chemistry Volume: 9 Pages: 799851-799851
  • DOI: 10.3389/fchem.2021.799851
  • Peer Reviewed / Open Access
• [Journal Article] Enlightening the Chemistry of Infalling Envelopes and Accretion Disks Around Sun-Like Protostars: The ALMA FAUST Project (2021)
  • Author(s): Codella C.、Ceccarelli C.、Chandler C.、Sakai N.、Yamamoto S.、The FAUST Team
  • Journal Title: Frontiers in Astronomy and Space Sciences Volume: 8
  • DOI: 10.3389/fspas.2021.782006
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Analytical development of seamless procedures on cation-exchange chromatography and ion-pair chromatography with high-precision mass spectrometry for short-chain peptides. (2021)
  • Author(s): Takano, Y., Oba, Y., Furota, S., Naraoka, H., Ogawa, N., Blattmann, T. M. and Ohkouchi, N.
  • Journal Title: Inter. J. Mass Spectrom. Volume: 462 Pages: 116529-116529
  • DOI: 10.1016/j.ijms.2021.116529
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] イオンペアクロマトグラフィー／電子スプレーイオン化質量分析法（LC/ESI-MS）による短鎖ペプチド類のマススペクトル解析 (2021)
  • Author(s): 高野 淑識, 大場 康弘, 大河内 直彦
  • Journal Title: Researches in Organic Geochemistry Volume: 37 Pages: 15-43
  • Peer Reviewed / Open Access
• [Presentation] Detailed Analyses of Nucleobases and Other N-heterocycles in Samples Returned from Asteroid (101955) Bennu (2025)
  • Author(s): Y. Oba, T. Koga, Y. Takano, Y. Furukawa, S. Sunami, Y. Hirakawa, H. Naraoka, J. P. Dworkin, D. P. Glavin, H. C. Connolly Jr., D. S. Lauretta
  • Organizer: 3S2024
  • Int'l Joint Research
• [Presentation] 小惑星Bennuサンプル中の窒素複素環化合物 (2025)
  • Author(s): 大場康弘，古賀俊貴，高野淑識，奈良岡浩，Angel Mojarro, Jason P. Dworkin, Daniel P. Glavin, Harold C. Connolly Jr., Dante S. Lauretta
  • Organizer: 次世代アストロケミストリー全体集会
• [Presentation] Nucleobases and other N-heterocycles in samples returned from asteroid (101955) Bennu (2024)
  • Author(s): Y. Oba, T. Koga, Y. Takano, H. Naraoka, A. Mojarro, J. P. Dworkin, D. P. Glavin, H. C. Connolly Fr., D. S. Lauretta
  • Organizer: Goldschmidt2024
  • Int'l Joint Research
• [Presentation] Detection of nucleobases and other N-heterocycles in the sample returned from asteroid (101955) Bennu (2024)
  • Author(s): Y. Oba, T. Koga, Y. Takano, H. Naraoka, A. Mojarro, J. P. Dworkin, D. P. Glavin, H. C. Connolly Fr., D. S. Lauretta
  • Organizer: JPGU2024
  • Invited
• [Presentation] 我々の起源を宇宙に探る (2024)
  • Author(s): 大場康弘
  • Organizer: JPGU2024
  • Invited
• [Presentation] Nucleobases in the laboratory and asteroids (2024)
  • Author(s): Y. Oba
  • Organizer: Cosmic Rays 3
  • Int'l Joint Research / Invited
• [Presentation] Surface reactions of phosphine (PH3) with H or D atoms on icy surfaces at low temperatures (2024)
  • Author(s): T. Nguyen, Y. Oba, W. M. C. Sameera, A. Kouchi, N. Watanabe
  • Organizer: CPLT2024
  • Int'l Joint Research
• [Presentation] 炭素質小惑星Bennuに存在する窒素複素環化合物の分布 (2024)
  • Author(s): 大場康弘，古賀俊貴，高野淑識，奈良岡浩，Angel Mojarro, Jason P. Dworkin, Daniel P. Glavin, Harold C. Connolly Jr., Dante S. Lauretta
  • Organizer: 有機地球化学シンポジウム
• [Presentation] Experimental Approaches for Reproducing the Distribution of N-Heterocyclic Molecules in Carbonaceous Asteroids (2024)
  • Author(s): Y. Oba, T. Koga, Y. Takano, N. Naraoka
  • Organizer: Solar System Symposium 2024
  • Int'l Joint Research
• [Presentation] 炭素質小惑星Bennuに含まれる窒素複素環化合物について (2024)
  • Author(s): 大場康弘, 古賀俊貴，高野淑識，奈良岡浩，A. Mojarro, J. P. Dworkin, D. P. Glavin
  • Organizer: 次世代アストロケミストリー第4回全体集会
• [Presentation] Detection of nucleobases in extraterrestrial materials using liquid chromatography coupled with ultra high-resolution mass spectrometry (2023)
  • Author(s): Yasuhiro Oba
  • Organizer: JpGU2023
  • Int'l Joint Research / Invited
• [Presentation] Chemical evolution from molecular clouds to star-forming regions, and beyond (2023)
  • Author(s): Yasuhiro Oba
  • Organizer: Chemical Processes in Solar-type Star Forming Regions
  • Int'l Joint Research / Invited
• [Presentation] Organic molecules in the asteroid Ryugu and their potential formation pathways (2023)
  • Author(s): Yasuhiro Oba
  • Organizer: Sapporo-Colombo-Gothenburg Astrochemistry Meeting 2023
  • Int'l Joint Research
• [Presentation] 炭素質小惑星リュウグウに存在する窒素複素環化合物の分布 (2023)
  • Author(s): 大場康弘，古賀俊貴，高野淑識，奈良岡浩
  • Organizer: 第40回有機地球化学シンポジウム
• [Presentation] Chemical evolution from the interstellar medium to the solar system: Insight from the analysis of asteroidal materials (2023)
  • Author(s): Y. Oba
  • Organizer: ISM2023
  • Int'l Joint Research / Invited
• [Presentation] SEARCH FOR PRIMORDIAL NITROGEN-HETEROCYCLES OF ASTROCHEMICAL INTEREST IN THE AQUEOUS EXTRACTS FROM THE ASTEROID (162173) RYUGU AND ORGUEIL CI-METEORITE (2023)
  • Author(s): Y. Oba et al.
  • Organizer: LPSC2023
  • Int'l Joint Research
• [Presentation] Nucleobases in Carbonaceous Meteorites and Returned Samples from Asteroid (162173) Ryugu (2023)
  • Author(s): Y. Oba et al.
  • Organizer: Solar System Symposium in Sapporo 2023
  • Int'l Joint Research
• [Presentation] Nucleobases in space: insights from meteorite analyses and laboratory experiments (2022)
  • Author(s): 大場康弘
  • Organizer: 計算アストロバイオロジー2022
  • Invited
• [Presentation] Wide Diversity of Pyrimidine Nucleobases in Carbonaceous Meteorites (2022)
  • Author(s): Y. Oba et al.
  • Organizer: AbSciCon2022
  • Int'l Joint Research
• [Presentation] 星間塵表面における化学反応素過程研究の最前線 (2021)
  • Author(s): 大場康弘
  • Organizer: 日本地球化学会第68回年会
  • Invited
• [Presentation] Experimental studies on the surface reaction of atomic hydrogen with “exotic molecules” at low temperatures (2021)
  • Author(s): Oba, Yasuhiro
  • Organizer: Pacifichem2021
  • Int'l Joint Research / Invited
• [Presentation] 炭素質隕石中ヘキサメチレンテトラミンの検出とその化学進化における役割 (2021)
  • Author(s): 大場 康弘、高野 淑識、奈良岡 浩、古川 善博、橘 省吾、グラビン ダニエル、ドワーキン ジェイソン
  • Organizer: JPGU2021
• [Remarks] 研究室個人ホームページ
  • URL: http://www2.lowtem.hokudai.ac.jp/astro/oba/index1.html