Explanipedia

Elastic Properties of Returned Samples From Asteroid (162173) Ryugu Open

Keisuke Onodera, Yuta Ino, Satoshi Tanaka, Taïchi Kawamura, Takuya Ishizaki , et al. · 2025

The successful sample return from asteroid (162173) Ryugu by Hayabusa2 has contributed to our understanding of the solar system evolution. Over the course of the initial sample analysis, various measurements were conducted, such as mineral…

Hayabusa2#’s (98943) Torifune flyby in July 2026: Rapid asteroid characterization using an already-flying spacecraft for planetary defense Open

Masatoshi Hirabayashi, Makoto Yoshikawa, Masahiko Hayakawa, Yuya Mimasu, Naru Hirata , et al. · 2025

Planetary defense is an international effort to collaboratively assess and mitigate upcoming threats from small bodies potentially hitting the Earth. The recent success in NASA’s DART, the mission that successfully smashed its spacecraft i…

Characteristics of natural remanence records in fine-grained particles returned from asteroid Ryugu Open

Masahiko Sato, Yuki Kimura, Tadahiro Hatakeyama, Tomoki Nakamuna, Satoshi Okuzumi , et al. · 2025

New Issues in JAXA Projects and Clues for Solutions — Reviewing JAXA’s Systems Engineering/Project Management Reforms and Best Practices of Hayabusa2 Open

Yuto Takei, Shintaro NISHIHIRA, Atsushi Harayama, Yuya Mimasu, Takanao Saiki , et al. · 2025

The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites Open

Fridolin Spitzer, T. Kleine, Christoph Burkhardt, Timo Hopp, Tetsuya Yokoyama , et al. · 2024

The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region…

Phosphorus-rich grains in Ryugu samples with major biochemical potential Open

C. Pilorget, D. Baklouti, Jean‐Pierre Bibring, R. Brunetto, Motoo Ito , et al. · 2024

A primordial noble gas component discovered in the Ryugu asteroid and its implications Open

A. B. Verchovsky, F. A. J. Abernethy, M. Anand, I. A. Franchi, M. M. Grady , et al. · 2024

Ryugu is the C-type asteroid from which material was brought to Earth by the Hayabusa2 mission. A number of individual grains and fine-grained samples analysed so far for noble gases have indicated that solar wind and planetary (known as P…

Breunnerite grain and magnesium isotope chemistry reveal cation partitioning during aqueous alteration of asteroid Ryugu Open

Toshihiro Yoshimura, Daisuke Araoka, Hiroshi Naraoka, Saburo Sakai, Nanako O. Ogawa , et al. · 2024

Returned samples from the carbonaceous asteroid (162173) Ryugu provide pristine information on the original aqueous alteration history of the Solar System. Secondary precipitates, such as carbonates and phyllosilicates, reveal elemental pa…

Variations of organic functional chemistry in carbonaceous matter from the asteroid 162173 Ryugu Open

B. T. De Gregorio, George D. Cody, R. M. Stroud, A. L. D. Kilcoyne, Scott A. Sandford , et al. · 2024

Diffraction modelling of a 2023 March 5 stellar occultation by subkilometer-sized asteroid (98943) 2001 CC21 Open

Ko Arimatsu, Fumi Yoshida, Tsutomu Hayamizu, Miyoshi Ida, George L. Hashimoto , et al. · 2024

We present an analysis of a stellar occultation event caused by a near-Earth asteroid (98943) 2001 CC21, an upcoming flyby target in the Hayabusa2 extended mission, on 2023 March 5. To determine the asteroid’s shape from diffraction-affect…

Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu Open

Yoshinori Takano, Hiroshi Naraoka, Jason P. Dworkin, Toshiki Koga, Kazunori Sasaki , et al. · 2024

Pyrrhotites in asteroid 162173 Ryugu: Records of the initial changes on their surfaces with aqueous alteration Open

Hiroharu Yui, Shu‐hei Urashima, Morihiko Onose, Mayu Morita, Shintaro Komatani , et al. · 2024

A deep analysis for New Horizons’ KBO search images Open

Fumi Yoshida, Toshifumi Yanagisawa, Takashi Itō, Hirohisa Kurosaki, Makoto Yoshikawa , et al. · 2024

Observation datasets acquired by the Hyper Suprime-Cam (HSC) on the Subaru Telescope for NASA’s New Horizons mission target search were analyzed through a method devised by JAXA. The method makes use of Field Programmable Gate arrays and w…

Incipient space weathering on asteroid 162173 Ryugu recorded by pyrrhotite Open

Dennis Harries, Toru Matsumoto, F. Langenhorst, T. Noguchi, Akira Miyake , et al. · 2024

Regolith samples returned from asteroid 162173 Ryugu by the Hayabusa2 mission provide direct means to study how space weathering operates on the surfaces of hydrous asteroids. The mechanisms of space weathering, its effects on mineral surf…

Simultaneous geometric calibration and orbit-attitude determination of Hayabusa2’s deployable camera (DCAM3) Open

Shota Kikuchi, K. Shirai, Ko Ishibashi, Koji Wada, Y. Yokota , et al. · 2024

Hayabusa2's deployable camera (DCAM3) was deployed from the spacecraft near the asteroid Ryugu to successfully monitor the artificial cratering experiment. Scientific analyses of the observed impact ejecta require accurate determination of…

Enantioselective three-dimensional high-performance liquid chromatographic determination of amino acids in the Hayabusa2 returned samples from the asteroid Ryugu Open

Aogu Furusho, Chiharu Ishii, Takeyuki Akita, Mai Oyaide, Masashi Mita , et al. · 2024

The chirality of amino acids in extraterrestrial materials may provide an insight into the origin of the essential l-enantiopure amino acids in the terrestrial biosphere. In 2020, the Hayabusa2 mission succeeded in bringing back surface ma…

The Earth atmosphere‐like bulk nitrogen isotope composition obtained by stepwise combustion analyses of Ryugu return samples Open

K. Hashizume, Akizumi Ishida, Ayano Chiba, Ryuji Okazaki, Kasumi Yogata , et al. · 2024

The nitrogen isotope compositions of two samples returned from the asteroid Ryugu were determined using a stepwise combustion method, along with Ivuna (CI) and Y‐980115, a CI‐like Antarctic meteorite, as references. The two Ryugu samples A…

Nonmagnetic framboid and associated iron nanoparticles with a space-weathered feature from asteroid Ryugu Open

Yuki Kimura, Takeharu Kato, Satoshi Anada, Ryuji Yoshida, Kazuo Yamamoto , et al. · 2024

Extraterrestrial minerals on the surface of airless Solar System bodies undergo gradual alteration processes known as space weathering over long periods of time. The signatures of space weathering help us understand the phenomena occurring…

Microscale hydrogen, carbon, and nitrogen isotopic diversity of organic matter in asteroid Ryugu Open

L. R. Nittler, Jens Barosch, Katherine Burgess, R. M. Stroud, Jianhua Wang , et al. · 2024

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Coevolution of phyllosilicate, carbon, sulfide, and apatite in Ryugu's parent body Open

Z. Gainsforth, G. Domingúez, Kana Amano, Megumi Matsumoto, Yuri Fujioka , et al. · 2024

We analyzed an asteroid Ryugu sample returned to Earth by JAXA's Hayabusa2 mission using nanoIR, SEM, and TEM microscopy. We identified multiple distinct carbon reservoirs within the phyllosilicate matrix and demonstrate infrared spectral …

Microscale Hydrogen, Carbon, and Nitrogen Isotopic Diversity of Organic Matter in Asteroid Ryugu Open

L. R. Nittler, Jens Barosch, Katherine Burgess, R. M. Stroud, Jianhua Wang , et al. · 2024

We report the H, C, and N isotopic compositions of microscale (0.2 to 2$μ$m) organic matter in samples of asteroid Ryugu and the Orgueil CI carbonaceous chondrite. Three regolith particles of asteroid Ryugu, returned by the Hayabusa2 space…

Mercury (Hg) in Ryugu particles and implications for the origin of volatile elements in early Earth Open

Naoki Shirai, Motoo Ito, A. Yamaguchi, Naotaka Tomioka, Masayuki Uesugi , et al. · 2024

Solar system abundances of the elements, which are determined by spectroscopic measurements of the solar photosphere and laboratory analyses of CI (Ivuna-type) carbonaceous chondrites, are a cornerstone to understand the origin and evoluti…

Disequilibrium oxygen isotope distribution among aqueously altered minerals in Ryugu asteroid returned samples Open

N. T. Kita, Kouki Kitajima, K. Nagashima, Noriyuki Kawasaki, Naoya Sakamoto , et al. · 2024

Oxygen 3‐isotope ratios of magnetite and carbonates in aqueously altered carbonaceous chondrites provide important clues to understanding the evolution of the fluid in the asteroidal parent bodies. We conducted oxygen 3‐isotope analyses of…

Unraveling the Cr Isotopes of Ryugu: An Accurate Aqueous Alteration Age and the Least Thermally Processed Solar System Material Open

Ryoji Tanaka, Dilan M. Ratnayake, Tsutomu Ota, N. Miklusicak, T. Kunihiro , et al. · 2024

The analysis of samples returned from the C-type asteroid Ryugu has drastically advanced our knowledge of the evolution of early solar system materials. However, no consensus has been obtained on the chronological data, which is important …

Three-dimensional textures of Ryugu samples and their implications for the evolution of aqueous alteration in the Ryugu parent body Open

A. Tsuchiyama, Megumi Matsumoto, Junya Matsuno, Masahiro Yasutake, Tomoki Nakamura , et al. · 2024

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Foundations of Molecular 'Isotomics' Open

Jaime César, Brooke Dallas, Laura Chimiak, Kliti Grace, Matthieu Clog , et al. · 2024

The naturally occurring rare isotopes are versions of common elements, such as hydrogen, carbon and oxygen, that contain a larger than usual number of neutrons in their atomic nuclei and therefore are higher in mass than the common atoms o…

Correlated IR-SEM-TEM studies of three different grains from Ryugu: From the initial material to post-accretional processes Open

Alice Aléon‐Toppani, R. Brunetto, Z. Dionnet, Stefano Rubino, D. Baklouti , et al. · 2024

AFM-IR nanospectroscopy of nanoglobule-like particles in Ryugu samples returned by the Hayabusa2 mission Open

Jérémie Mathurin, Laure Bejach, E. Dartois, C. Engrand, Alexandre Dazzi , et al. · 2024

Context . The JAXA Hayabusa2 mission returned well-preserved samples collected from the carbonaceous asteroid Ryugu, providing unique non-terrestrially weathered samples from a known parent body. Aims . This work aims to provide a better u…

Hydrogen in magnetite from asteroid Ryugu Open

J. Aléon, S. Mostefaoui, Hélène Bureau, Divine Vangu, H. Khodja , et al. · 2024

In order to gain insights on the conditions of aqueous alteration on asteroid Ryugu and the origin of water in the outer solar system, we developed the measurement of water content in magnetite at the micrometer scale by secondary ion mass…

Microstructural and chemical features of impact melts on Ryugu particle surfaces: Records of interplanetary dust hit on asteroid Ryugu Open

Megumi Matsumoto, Junya Matsuno, A. Tsuchiyama, Tomoki Nakamura, Yuma Enokido , et al. · 2024

The Hayabusa2 spacecraft delivered samples of the carbonaceous asteroid Ryugu to Earth. Some of the sample particles show evidence of micrometeoroid impacts, which occurred on the asteroid surface. Among those, particles A0067 and A0094 ha…

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