The first results obtained by the OSIRIS-REx SEIWG team lead by Jess Barnes and Anh Nguyen are now published in Nature Astronomy. The paper includes SIMS measurements of the oxygen isotopes we have obtained on our instruments at CRPG. Check it out !

Barnes, J.J., Nguyen, A.N., Abernethy, F.A.J., Bajo, K., Bekaert, D. V, Bloch, E., Brennecka, G.A., Busemann, H., Cowpe, J.S., Crowther, S.A., Ek, M., Fawcett, L.J., Fehr, M.A., Franchi, I.A., Füri, E., Gilmour, J.D., Grady, M.M., Greenwood, R.C., Haenecour, P., Kawasaki, N., Koefoed, P., Krietsch, D., Le, L., Liszewska, K.M., Maden, C., Malley, J., Marrocchi, Y., Marty, B., Meyer, L.A.E., Peretyazhko, T.S., Piani, L., Render, J., Russell, S.S., Rüfenacht, M., Sakamoto, N., Schönbächler, M., Shollenberger, Q.R., Smith, L., Thomas-Keprta, K., Verchovsky, A.B., Villeneuve, J., Wang, K., Welten, K.C., Wimpenny, J., Worsham, E.A., Yurimoto, H., Zimmermann, L., Zhao, X., Alexander, C.M.O., Amini, M., Baczynski, A., Bland, P., Borg, L.E., Burgess, R., Caffee, M.W., Chaves, L.C., Clay, P.L., Dworkin, J.P., Foustoukos, D.I., Glavin, D.P., Hamilton, V.E., Hill, D., House, C.H., Huss, G.R., Ireland, T., Jilly, C.E., Jourdan, F., Keller, L.P., Kruijer, T.S., Lai, V., McCoy, T.J., Nagashima, K., Nishiizumi, K., Ogliore, R., Ong, I.J., Reddy, S.M., Rickard, W.D.A., Sandford, S., Saxey, D.W., Timms, N., Weis, D., Wilbur, Z.E., Zega, T.J., DellaGiustina, D.N., Wolner, C.W. V, Connolly, H.C., Lauretta, D.S., 2025. The variety and origin of materials accreted by Bennu’s parent asteroid. Nat Astron. https://doi.org/10.1038/s41550-025-02631-6

Abstract

The first bodies to form in the Solar System acquired their materials from stars, the presolar molecular cloud and the protoplanetary disk. Asteroids that have not undergone planetary differentiation retain evidence of these primary accreted materials. However, geologic processes such as hydrothermal alteration can dramatically change their bulk mineralogy, isotopic compositions and chemistry. Here we analyse the elemental and isotopic compositions of samples from asteroid Bennu to uncover the sources and types of material accreted by its parent body. We show that some primary accreted materials escaped the extensive aqueous alteration that occurred on the parent asteroid, including presolar grains from ancient stars, organic matter from the outer Solar System or molecular cloud, refractory solids that formed close to the Sun, and dust enriched in neutron-rich Ti isotopes. We find Bennu to be richer in isotopically anomalous organic matter, anhydrous silicates, and light isotopes of K and Zn than its closest compositional counterparts, asteroid Ryugu and Ivuna-type (CI) carbonaceous chondrite meteorites. We propose that the parent bodies of Bennu, Ryugu and CI chondrites formed from a common but spatially and/or temporally heterogeneous reservoir of materials in the outer protoplanetary disk.

Two review papers have been published on the aqueous alteration processes in chondrites in the framework of the workshop « Evolution of the Solar System: Constraints from Meteorites » at the International Space Science Institute (ISSI) in Bern in June 2023. The links for the papers are below !

Krot, A. N., Petaev, M. I., Piani, L., Marrocchi, Y., Fujiya, W., Pravdivtseva, O. V, Dobrică, E., Vacher, L. G., King, A. J., Lee, M., Van Kooten, E., Jacobsen, B., Alexander, C. M. O., Bischoff, A., Brearley, A. J., Le Guillou, C., Remusat, L., Leitner, J., & Huss, G. R. (2025). Metasomatic Alteration of Type 3 Ordinary and Carbonaceous Chondrites. Space Science Reviews, 221(1), 7. https://doi.org/10.1007/s11214-025-01135-z

Lee, M. R., Alexander, C. M. O., Bischoff, A., Brearley, A. J., Dobrică, E., Fujiya, W., Le Guillou, C., King, A. J., van Kooten, E., Krot, A. N., Leitner, J., Marrocchi, Y., Patzek, M., Petaev, M. I., Piani, L., Pravdivtseva, O., Remusat, L., Telus, M., Tsuchiyama, A., & Vacher, L. G. (2025). Low-Temperature Aqueous Alteration of Chondrites. Space Science Reviews, 221(1), 11. https://doi.org/10.1007/s11214-024-01132-8

Les mesures ont commencé depuis mi-novembre sur les premiers grains de l’astéroïde carboné Bennu extraits de la capsule d’OSIRIS-REx (NASA). Nous participons à ces premières analyses au CRPG avec des mesures en sonde ionique et aux gaz rares. Cet article dans le journal du CNRS parle de notre implication avec d’autres équipes françaises.

@ Nasa / Goddard / University of Arizona

In this paper, we confirm the high hydrogen content in enstatite chondrite chondrule mesostasis and show that hydrogen is linked to sulfur in the chondrule glass.

Thomassin D., Piani L., Villeneuve J., Caumon MC., Bouden N., Marrocchi Y. (2023) The high-temperature origin of hydrogen in enstatite chondrite chondrules and implications for the origin of terrestrial water. Earth and Planetary Science Letters 616, 118225. doi: 10.1016/j.epsl.2023.118225

Un article de review dans la revue Elements co-écrit avec André Izidoro (Rice University) sur l’origine de l’eau de la Terre et des planètes rocheuses vue par le prisme des météorites et des modèles de formation planétaire :

Izidoro A., Piani L. (2022) Origin of Water in the Terrestrial Planets: Insights from Meteorite Data and Planet Formation Models. Elements 2022;; 18 (3): 181–186. doi: 10.2138/gselements.18.3.181

Broadley M.W., Bekaert D.V., Piani L., Füri E. & Marty B. Origin of life-forming volatile elements in the inner Solar System. Nature 611, 245–255 (2022). https://doi.org/10.1038/s41586-022-05276-x

The first results obtained by the Hayabusa 2 initial-analysis chemistry team lead by Professors T. Yokoyama and H. Yurimoto are now published in Science. Results shows that the fragments of Ryugu returned by the Hayabusa 2 space mission are close CI-type carbonaceous chondrite meteorites but with less water indicated that this could be a more pristine material than CIs.

Yokoyama T., Nagashima K., Nakai I., Young E. D., …, Piani L., …(140 authors), Shogo Tachibana, Hisayoshi Yurimoto. Science, June 2022. Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites. DOI : 10.1126/science.abn7850

Abstract

Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measure the mineralogy, bulk chemical and isotopic compositions of Ryugu samples. They are mainly composed of materials similar to carbonaceous chondrite meteorites, particularly the CI (Ivuna-type) group. The samples consist predominantly of minerals formed in aqueous fluid on a parent planetesimal. The primary minerals were altered by fluids at a temperature of 37 ± 10°C, 5.2^+0.7_/−0.8 million years after formation of the first solids in the Solar System. After aqueous alteration, the Ryugu samples were likely never heated above ~100°C. The samples have a chemical composition that more closely resembles the Sun’s photosphere than other natural samples do.