162173 Ryugu

Apollo asteroidsection June 2026 Missing recent research, e.g. arXiv:2609.04973Ryugu the Japanese folklore palace Ryūgū-jō October 2018 yes 162173 Ryugu #FFC2E0 162173 Ryugu brightened.png Ryugu photographed by Hayabusa2 in September 2018 LINEAR Lincoln Lab's ETS 10 May 1999 (162173) Ryugu 1999 JU 3 ja ɾjɯːɡɯː lang;in English, spelling-pronunciation r aI ' j uː g uː or approximated ' j uː g uː or ' r uː g uː Ryūgū("Dragon palace") ApolloNEOPHA 12 December 2011 (JD 2455907.5) 0 30.32 yr (11,075 d) 1.4159 AU 0.9633 AU 1.1896 AU 0.1902 1.30 yr (474 d) 3.9832° 0.7596 ms / day 5.8837° 251.62° 211.43° 0.0006 AU (0.2337 LD) 1004 x 876 m 448 2 m 502 2 m 438 2 m 1/80,000 g 7.63262 0.00002 h 171.64 0.03 ° +96.40 0.03 ° −66.40 0.03 ° 0.377 0.005 km3 1.19 0.03 g cm−3 4.50 0.06 11 kg 0.037 0.0020.042 0.0030.047 0.0030.063 0.0200.07 0.010.078 0.013 SMASS CgCCb 18.69 0.07 (R)18.8219.219.25 0.0319.3 162173 Ryugu (provisional designation 1999 JU 3) is a near-Earth object and also a potentially hazardous asteroid of the Apollo group. It measures approximately 900 m ft in diameter and is a dark object of the rare spectral type Cb,Sugita S. Honda R. Morota T. Kameda S. Sawada H. Tatsumi E. Honda C. Yokota Y. Yamada M. Kouyama T. Sakatani N. July 2019 Ryugu's Parent-Body Processes Estimated from Hayabusa2 Multi-Band Optical Observations 82nd Annual Meeting of The Meteoritical Society, held 7-12 July, 2019 in Sapporo, Japan en LPI Contribution 2157 6366 0161-5297 2019LPICo2157.6366S with qualities of both a C-type asteroid and a B-type asteroid. In June 2018, the Japanese spacecraft Hayabusa2 arrived at the asteroid.Chang Kenneth Stirone Shannon The Asteroid Was Shooting Rocks Into Space. 'Were We Safe in Orbit?' NASA's Osiris-Rex and Japan's Hayabusa2 spacecraft reached the space rocks they are surveying last year, and scientists from both teams announced early findings on Tuesday. https://www.nytimes.com/2019/03/19/science/bennu-ryugu-asteroids.html 19 March 2019 The New York Times 21 March 2019 After making measurements and taking samples, Hayabusa2 left Ryugu for Earth in November 2019https://spaceflightnow.com/2019/11/13/japanese-sample-return-craft-departs-asteroid-heads-for-earth Japanese sample return craft departs asteroid, heads for Earth November 13, 2019 Stephen Clark/ and returned the sample capsule to Earth on 5 December 2020. The samples showed the presence of organic compounds, such as uracil (one of the four components in RNA) and vitamin B3. Discovery and name Ryugu was discovered on 10 May 1999 by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Lab's ETS near Socorro, New Mexico, in the United States. It was given the provisional designation 1999 JU 3. The asteroid was officially named "Ryugu" by the Minor Planet Center on 28 September 2015 (M.P.C. 95804). The name refers to Ryūgū-jō (Dragon Palace), a magical underwater palace in a Japanese folktale. In the story, the fisherman Urashima Tarō travels to the palace on the back of a turtle, and when he returns, he carries with him a mysterious box, much like Hayabusa2 returning with samples. Geological history Ryugu formed as part of an asteroid family, belonging either to Eulalia or Polana.Sugita S. Honda R. Morota T. Kameda S. Honda C. Yokota Y. Yamada M. Kouyama T. Sakatani N. Suzuki H. Yoshioka K. March 2019 The Evolution of Ryugu's Parent Body Constrained by Hayabusa2 Imaging Observations LPI en 2132 2622 2019LPI....50.2622S Those asteroid families are most likely fragments of past asteroid collisions. The large number of boulders on the surface supports a catastrophic disruption of the parent body. The parent body of Ryugu probably experienced dehydration due to internal heating and must have formed in an environment without a strong magnetic field. After this catastrophic disruption, part of the surface was reshaped again by the high speed rotation of the asteroid forming the equatorial ridge (Ryujin Dorsum), through internal failure and/or mass wasting. The geologically distinct western area ('Western bulge') is probably the result of asymmetrical internal failure. It is hoped that surface samples will help to reveal more of the geological history of the asteroid. Ryugu is hypothesized to be an extinct comet.Miura H. Nakamura E. Kunihiro T. The Asteroid 162173 Ryugu: a Cometary Origin The Astrophysical Journal Letters 2022 925 2 15 10.3847/2041-8213/ac4bd5 2022ApJ...925L..15M free Characteristics Orbit thumb|The origin of 162173 Ryugu may be either 495 Eulalia or 142 Polana.The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes Science 364 6437 eaaw0422 S. Sugita etal 19 Mar 2019 10.1126/science.aaw0422 30890587 7370239 2019Sci...364..252S 1893/29363 free Yellow Sun RoyalBlue EarthLime 162173 RyuguOrangeRed 142 PolanaCyan 495 Eulalia Ryugu orbits the Sun at a distance of 0.96–1.41 AU once every 16 months (474 days; semi-major axis of 1.19 AU). Its orbit has an eccentricity of 0.19 and an inclination of 6° with respect to the ecliptic. It has a minimum orbital intersection distance with Earth of 0.000638 AU km 3 flip, equivalent to 0.23 lunar distances. Physical Early analysis in 2012 by Thomas G. Müller et al. used data from a number of observatories, and suggested that the asteroid was "almost spherical", a fact that hinders precise conclusions, with retrograde rotation, an effective diameter of 0.85–0.88 km (0.528 miles) and a geometric albedo of 0.044 to 0.050. They estimated that the grain sizes of its surface materials are between 1 and 10 mm. Initial images taken by the Hayabusa2 spacecraft on approach at a distance of 700 km were released on 14 June 2018. They revealed a diamond-shaped body 1 km in diameter and confirmed its retrograde motion. Between 17 and 18 June 2018, Hayabusa2 went from 330 to 240 km from Ryugu and captured a series of additional images from the closer approach. Astronomer Brian May created stereoscopic images from data collected a few days later.Bartels Meghan Queen's Brian May Will Rock You with This Stereo Image of Asteroid Ryugu https://www.space.com/41119-brian-may-asteroid-ryugu-hayabusa2-image.html 10 July 2018 Space.com 24 December 2018 After a few months of exploration, JAXA scientists concluded that Ryugu is actually a rubble pile with about 50% of its volume being empty space.Hayabusa-2: Asteroid mission exploring a 'rubble pile'. Paul Rincon, BBC News. 19 March 2019. The acceleration due to gravity at the equator has been evaluated at about 0.11 mm/s2, rising to 0.15 mm/s2 at the poles. The mass of Ryugu is estimated at 450 million tonnes. The asteroid has a volume of 0.377 ± 0.005 km3 and a bulk density of 1.19 ± 0.03 g/cm3 based on the shape model.Watanabe S. Hirabayashi M. Hirata N. Hirata N. Noguchi R. Shimaki Y. etal April 2019 Hayabusa2 arrives at the carbonaceous asteroid 162173 Ryugu—A spinning top–shaped rubble pile Science 364 en 6437 268–272 10.1126/science.aav8032 2019Sci...364..268W 30890588 84183033 free Shape thumb|left|Image sequence showing the rotation of Ryugu Ryugu has a round shape with an equatorial ridge, called Ryujin Dorsum. Ryugu is a spinning top-shape asteroid similar to Bennu. The ridge was shaped by strong centrifugal forces during a phase of high-speed rotation, through landslides and/or internal failure. The western side, also called the western bulge, has a distinct shape. It has a smooth surface with a sharp equatorial ridge. When modeling a high-speed rotation of present-day Ryugu, subsurface material appears structurally intact and relaxed in the western bulge, while other regions are more sensitive to structural failure. This indicates past structural failure in the western bulge (only the elements that did not experience structural failure previously are now sensitive to failure).Hirabayashi Masatoshi Tatsumi Eri Miyamoto Hideaki Komatsu Goro Sugita Seiji Watanabe Sei-ichiro Scheeres Daniel J. Barnouin Olivier S. Michel Patrick Honda Chikatoshi Michikami Tatsuhiro March 2019 The Western Bulge of 162173 Ryugu Formed as a Result of a Rotationally Driven Deformation Process Astrophysical Journal Letters en 874 1 L10 10.3847/2041-8213/ab0e8b 1904.03480 2019ApJ...874L..10H 102350610 0004-637X free The western bulge is bordered by the Tokoyo and Horai Fossae. Surface thumb|Images of the asteroid's surface made with Hayabusa2 Observations from Hayabusa2 showed that the surface of Ryugu is very young and has an age of 8.9 ± 2.5 million years based on the data collected from the artificial crater that was created with an explosive by Hayabusa2.Arakawa M. Saiki T. Wada K. Ogawa K. Kadono T. Shirai K. Sawada H. Ishibashi K. Honda R. Sakatani N. Iijima Y. 2020-03-19 An artificial impact on the asteroid 162173 Ryugu formed a crater in the gravity-dominated regime https://www.science.org/doi/10.1126/science.aaz1701 Science 368 6486 67–71 en 10.1126/science.aaz1701 32193363 2020Sci...368...67A 214591738 0036-8075 The surface of Ryugu is porous and contains no or very little dust. The measurements with the radiometer on board of MASCOT, which is called MARA, showed a low thermal conductivity of the boulders. This was an in situ measurement of the high porosity of the boulder material. This result showed that most meteorites originating from C-type asteroids are too fragile to survive the entry into Earth's atmosphere.https://www.dlr.de/content/en/articles/news/2019/03/20190715_mascot-confirms-what-scientists-have-long-suspected.html DLR – MASCOT confirms what scientists have long suspected DLRARTICLE DLR Portal en 2020-03-07Grott M. Knollenberg J. Hamm M. Ogawa K. Jaumann R. Otto K. A. Delbo M. Michel P. Biele J. Neumann W. Knapmeyer M. 2019-07-15 Low thermal conductivity boulder with high porosity identified on C-type asteroid (162173) Ryugu Nature Astronomy en 3 11 971–976 10.1038/s41550-019-0832-x 2019NatAs...3..971G 1893/29871 197402876 2397-3366 free The images from the camera of MASCOT, which is called MASCam, showed that surface of Ryugu contains two different almost black types of rock with little internal cohesion, but no dust was detected. One type of rocky material on the surface is brighter with a smooth surface and sharp edges. The other type of rock is dark with a cauliflower-like, crumbly surface. The dark type of rock has a dark matrix with small, bright, spectrally different inclusions. The inclusions appear similar to CI chondrites.Jaumann R. Schmitz N. Ho T.-M. Schröder S. E. Otto K. A. Stephan K. Elgner S. Krohn K. Preusker F. Scholten F. Biele J. 2019-08-23 Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites Science en 365 6455 817–820 10.1126/science.aaw8627 0036-8075 31439797 2019Sci...365..817J 201616571 https://hal.archives-ouvertes.fr/hal-02381801/file/aaw8627_CombinedPDF_v3.pdf https://www.dlr.de/content/en/articles/news/2019/03/20190822_the-near-earth-asteroid-ryugu-a-fragile-cosmic-rubble-pile.html The near-Earth asteroid Ryugu – a fragile cosmic rubble pile DLRARTICLE DLR Portal en 2020-03-07 An unanticipated side effect from the Hayabusa2 thrusters revealed a coating of dark, fine-grained red material.Hayabusa-2 Reveals Surface of Near-Earth Asteroid Ryugu in Stunning Detail http://www.sci-news.com/space/hayabusa-2-surface-near-earth-asteroid-ryugu-08415.html May 11, 2020 Sci News May 12, 2020 Craters Ryugu has 77 craters on the surface. Ryugu shows variations of crater density that cannot be explained by randomness of cratering. There are more craters at lower latitudes and fewer at higher latitudes, and fewer craters in the western bulge (160°E – 290°E) than in the region around the meridian (300°E – 30°E). This variation is seen as evidence of a complicated geologic history of Ryugu.Hirata Naoyuki Morota Tomokatsu Cho Yuichiro Kanamaru Masanori Watanabe Sei-ichiro Sugita Seiji Hirata Naru Yamamoto Yukio Noguchi Rina Shimaki Yuri Tatsumi Eri March 2020 The spatial distribution of impact craters on Ryugu Icar en 338 113527 10.1016/j.icarus.2019.113527 2205.05818 2020Icar..33813527H 209903294 0019-1035 The surface has one artificial crater, which was intentionally formed by the Small Carry-on Impactor (SCI), which was deployed by Hayabusa2. SCI fired a 2 kg copper mass onto the surface of Ryugu on 5 April 2019.http://www.hayabusa2.jaxa.jp/en/topics/20190424e_CRA2_Schedule/ Apr. 24, 2019. What's new JAXA Hayabusa2 project ja 2020-03-09 The artificial crater showed a darker subsurface material. It created an Ejecta of 1 cm thickness and excavated material from up to 1 metre in depth.http://www.hayabusa2.jaxa.jp/en/enjoy/material/press/Hayabusa2_Press20190625_ver5_en2.pdf Asteroid explorer, Hayabusa2, reporter briefing June 25, 2019 JAXA Hayabusa2 Project 2020-03-09 Boulders Ryugu contains 4,400 boulders with a size larger than 5 metres. Ryugu has more large boulders per surface area than Itokawa or Bennu, about one boulder larger than 20 metres per 50 km2. The boulders resemble laboratory impact fragments. The high number of boulders is explained with a catastrophic disruption of Ryugu's larger parent body. The largest boulder, called Otohime, has a size of ~160 × 120 × 70 m and is too large to be explained as an ejected boulder from a crater.Michikami Tatsuhiro Honda Chikatoshi Miyamoto Hideaki Hirabayashi Masatoshi Hagermann Axel Irie Terunori Nomura Keita Ernst Carolyn M. Kawamura Masaki Sugimoto Kiichi Tatsumi Eri October 2019 Boulder size and shape distributions on asteroid Ryugu Icar en 331 179–191 10.1016/j.icarus.2019.05.019 2019Icar..331..179M 0019-1035 free 1893/29777 free Sample analysis results After the initial description (phase-1), part of the sample was distributed to the Hayabusa2 Initial Analysis Team, consisting of six sub-teams, and two Phase-2 curation institutes at Okayama University and JAMSTEC Kochi Institute for Core Sample Research.JAXA Asteroid Explorer Hayabusa2 Initial Analysis Chemical Analysis Team reveals aqueous alteration and primitive composition of asteroid Ryugu https://global.jaxa.jp/press/2022/06/20220610-2_e.html 2022-09-28 JAXA Japan Aerospace Exploration Agency en In September 2022 the Hayabusa 2 initial Analysis Stone Team announced the results of their study, which includes:JAXA Asteroid Explorer Hayabusa2 Initial Analysis Stone Team reveals the formation and evolution of carbonaceous asteroid Ryugu. https://global.jaxa.jp/press/2022/09/20220923-1_e.html 2022-09-28 JAXA Japan Aerospace Exploration Agency en Ryugu samples contain grains that were formed at high temperatures above 1000 °C, which formed close to the Sun and were later transported towards the outer Solar System. The samples are soft enough to be cut with a knife and the samples preserve the magnetic field like a hard disk. A simulation of the formation was performed, which showed that the parent body of Ryugu accumulated 2 million years after the formation of the Solar System. It heated up to 50 °C over the next 3 million years, resulting in reactions of rocky material with water. In these reactions anhydrous silicates became hydrous silicates and iron became magnetite. The 100 km large parent body was then destroyed by a <10 km large impactor, with an impact speed of about 5 km/s. Ryugu then formed from material far from the impact. In March 2026, all five canonical nucleobases were found from these samples.Koga Toshiki Oba Yasuhiro Takano Yoshinori Naraoka Hiroshi Ogawa Nanako O. Sasaki Kazunori Sato Hajime Yoshimura Toshihiro Ohkouchi Naohiko 2026-03-16 A complete set of canonical nucleobases in the carbonaceous asteroid (162173) Ryugu https://www.nature.com/articles/s41550-026-02791-z Nature Astronomy en 1–9 10.1038/s41550-026-02791-z 2397-3366 Origin from the outer Solar System The deuterium-rich and nitrogen-15-rich isotopic compositions of fine-grained minerals and organics suggests that the parent body of Ryugu formed in the outer Solar System.JAXA Asteroid Ryugu is a drifter from the outer Solar System: Results from the Hayabusa2 Phase-2 Curation Kochi Team published in Nature Astronomy https://global.jaxa.jp/press/2022/08/20220816-1_e.html 2022-09-28 JAXA Japan Aerospace Exploration Agency en Titanium, chromium and molybdenum isotopic anomalies provide more evidence that ties Ryugu's origin to the outer Solar System.2022 Ryugu's nucleosynthetic heritage from the outskirts of the Solar System Science Advances (2022): eadd8141. Science Advances 8 46 3 10.1126/sciadv.add8141 Hopp Timo Dauphas Nicolas Abe Yoshinari Aléon Jérôme O'd. Alexander Conel M. Amari Sachiko Amelin Yuri Bajo Ken-Ichi Bizzarro Martin Bouvier Audrey Carlson Richard W. Chaussidon Marc Choi Byeon-Gak Davis Andrew M. Di Rocco Tommaso Fujiya Wataru Fukai Ryota Gautam Ikshu Haba Makiko K. Hibiya Yuki Hidaka Hiroshi Homma Hisashi Hoppe Peter Huss Gary R. Ichida Kiyohiro Iizuka Tsuyoshi Ireland Trevor R. Ishikawa Akira Ito Motoo Itoh Shoichi 36264823 253045585 1 free 20.500.11850/583897 free Based on preserved magnetism in the samples researchers concluded that the parent body of Ryugu was probably formed in the darkness of nebular gas. Volatiles Water The Hayabusa2 sample capsule was significantly upgraded from Hayabusa, to preserve water, light organics, gases, and other volatiles.Yada T. Fujimura Abe M. Nakamura T. Noguchi T Okazaki R. Nagao K. Ishibashi Y. Shirai K. Zolensky M. E. Sandford S. Okada T. Uesugi M. Karouji Y. Ogawa M. Yakame S. Ueno M. Mukai T. Yoshikawa M. Kawaguchi J. 2014 Hayabusa-returned sample curation in the Planetary Material Sample Curation Facility of JAXA Met. & Planet. Sci. 49 2 135 10.1111/maps.12027 2014M&PS...49..135Y 56357760 free Abe M. Yada T. Okada T. Sakamoto K. Yoshitake M. Nakano Y. Matsumoto T. Kawasaki N. Kumagai K. Matsui S. Nishimura M. Yurimoto H. 2017 Readiness of Receiving and Curation facility for Hayabusa2 Asteroid Sample Return Mission Hayabusa 2017 https://curation.isas.jaxa.jp/symposium/abstract/2017/1204_1100_Masanao_Abe.pdf This water was successfully sampled and preserved.Nittler L. R. 2022 Can SIMS measurements constrain the D/H ratio of water on Ryugu? 2022 Hayabusa Symposium S21-02 Piani L. Marrocchi Nagashima Kawasaki Sakamoto Bajo Yurimoto 2022 H isotopic composition of water in Ryugu samples returned by the Hayabusa2 mission 85th MetSoc 6058 Nittler L. R. Barosch J. Wang J. Alexander C. M. O'D. 2023 Water in Asteroid Ryugu is Deuterium-Rich Compared to Earth and CI Chondrites 54th LPSC Yesiltas M. Glotch T. D. Kebukawa Y. Northrup P. Sava B. 2023 Nano-Scale Infrared and Raman Spectroscopy of Ryugu Particles 86th Meteoritical Society Meeting 6161 Via a bulk sample (~95 milligrams), its water content was reported as 6.84 ±0.34 wt%.Yokoyama T. Nagashima K. Nakai I. Young E. D. ((and 145 coauthors)) Samples returned from the asteroid Ryugu are similar to Ivuna-type carbonaceous meteorites Science 2023 379 6634 10.1126/science.abn7850 35679354 2023Sci...379.7850Y 249544031 https://hal.science/hal-03825124/file/Yokoyama-et-al_2022_science.abn7850.pdf Independently, a research group with a far smaller allocation (particles) reported 4–7 percent water.Verchovsky A. B. Abernethy F. A. J. Anand M. Franchi I. A. Grady M. M. Greenwood R. C. Suttle M. Ito M. Tomioka N. Uesugi M. Yamaguchi A. Kimura M. Imae N. Shirai N. Ohigashi T. Liu M-C. Yada T. Abe M. Usui T. 2023 Ryugu's volatiles investigated using stepped combustion and EGA methods 54th LPSC 2471 The lower-than-expected water signature seen by Hayabusa2 instruments was the result of space weathering, producing a dehydrated rind.Taaki Noguchi T. Matsumoto Y Tsuda 19 Dec 2022 A dehydrated space-weathered skin cloaking the hydrated interior of Ryugu Nature 7 170 10.1038/s41550-022-01841-6 2023NatAs...7..170N 254908999 free 36845884 2433/279328 free Tachibana S. Hayabusa2 and Sample Science – JAXA NASA Small Bodies Assessment Group July 2023 Meeting Jul 12, 2023Hamann C. Bonato E. Maturilli A. Mahlow K. Patzschke M. Alemanno G. Schwinger S. Van den Neucker A. Baqué M. Greshake A. Hecht L. Helbert J. CRISPY On The OUTSIDE, RAW On The INSIDE: IMPACT-INDUCED MELTING And FRAGMENTATION Of C-Type ASTEROID Regolith DocumentedIn A Ryugu Sample 86th Meteoritical Society Meeting Aug 11, 2023 6296 Liquid water and aqueous alteration Carbonated liquid water was discovered in one crystal. The water contained salts and organic matter. The liquid water was found inside a hexagonal iron sulfide crystal. The carbon dioxide was most likely CO2-ice (dry ice) inside the parent body. The water ice melted soon after the parent body formed and the CO2 dissolved into the water.Zolensky M. Dolocan A. Bodnar R. Gearba I. Martinez J. Han J. Nakamura T. Tsuchiyama A. Matsuno J. Sun M. Matsumoto M. Fujioka Y. Enokido Y. Uesugi K. Takeuchi A. Yasutake M. Miyake A. Okumura S. Mitsukawa I. Takigawa A. Mikouchi T. Enju S. Morita T. Kikuiri M. Amano K. Yurimoto H. Noguchi T. Okazaki R. Yabuta H. Naraoka H. Sakamoto K. Tachibana S. Watanabe S. Tsuda Y 2022 Direct Measurement of the Composition of Aqueous Fluids from the Parent Body of Asteroid 162173 Ryugu 53rd Lun. Plan. Sci. Conf 1451 Nakamura T Matsumoto M. Amano K. ((and 70+ coauthors)) 2022 Early History of Ryugu's Parent Asteroid: Evidence from Return Sample 53rd LPSC 1753 Crystals "shaped like coral reefs" were found. These crystals probably formed in liquid water, which was once present in the interior of the parent body. The parent body had a dryer surface and a wetter interior. After the collision of the parent body with a smaller asteroid, the interior and surface material were mixed. Today Ryugu has both interior and parent body surface material on its surface. An international team found particles in the samples that contained small amounts of material unaltered by water. The team found about 0.5 vol% of anhydrous silicates. The isotopic analysis of the magnesium-rich olivine and pyroxene in the sample suggests that two types of high-temperature objects accreted onto the surface of Ryugu: amoeboid olivine aggregates and magnesium-rich chondrules.Team identifies parent body materials in Ryugu asteroid https://www.llnl.gov/news/team-identifies-parent-body-materials-ryugu-asteroid 2022-09-28 www.llnl.gov en Gas Hayabusa2 recovered helium and other noble gases. Some terrestrial contamination entered the system, but the Ryugu components are still measurable.Okazaki R. Miura Y. N. Takano Y. Sawada H. Sakamoto K. Yada T. Yamada K. Kawagucci S. Matsui Y. ((and 115 others)) 20 Oct 2022 First asteroid gas sample delivered by the Hayabusa2 mission: a treasure box from Ryugu Science Advances 8 46 eabo7239 10.1126/sciadv.abo7239 36264781 2022SciA....8O7239O 253045236 free 20.500.11850/583894 free Okazaki R. Marty B. Busemann H. Hashizumi K. Gilmour J. D. Meshik A. Yada T. Kitajima F. Broadley M. W. ((and 114 others)) 2023 Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution Science 379 6634 10.1126/science.abo0431 2023Sci...379.0431O 253045328 https://hal.science/hal-03891762 Busemann H. Krietsch D. Mertens C. A. K. Maden C. Recently Recovered Pristine Extraterrestrial Materials As Carriers of Primordially Trapped Noble Gases 86th Meteoritical Society Meeting Aug 11, 2023 6211 Verchovsky A. B. Abernethy F. A. J. Anand M. Franchi I. A. Grady M. M. Greenwood R. C. Barber S. J. Suttle M. Ito M. Tomioka N. Uesugi M. Yamaguchi A. Kimura M. Imae N. Shirai N. Ohigashi T. Liu M-C. Yada T. Abe M. Usui T. 2023 Extremely High Xe Concentration in The Hayabusa2 C0209 Sample 54th LPSC 6323 Organic molecules Aliphatic carbon-rich organics associated with coarse-grained phyllosilicates were found. Such an association has not been observed in any meteorite study and could be unique to the asteroid Ryugu. In samples retrieved on Ryugu from the Japanese Hayabusa2 spacecraft, scientists discovered 20 different amino acids.'Rubber-ducky' asteroid 200 million miles away holds building blocks of life Ben Turner, LiveScience. June 9, 2022 In March 2023, scientists announced that uracil and vitamin B3 were detected in samples retrieved from Ryugu. Unlike previous instances when nucleobases and vitamins were found in certain carbon-rich meteorites, the samples were collected directly from the asteroid and delivered to Earth in sealed capsules, which meant Earthside contamination was not possible.https://edition.cnn.com/2023/03/21/world/ryugu-asteroid-organic-molecules-scn/index.html RNA compound and vitamin B3 found in samples from near-Earth asteroid CNN Ashley Strickland 22 March 2023 22 March 2023Oba Yasuhiro Koga Toshiki Takano Yoshinori Ogawa Nanako O. Ohkouchi Naohiko Sasaki Kazunori Sato Hajime Glavin Daniel P. Dworkin Jason P. Naraoka Hiroshi Tachibana Shogo Yurimoto Hisayoshi Nakamura Tomoki Noguchi Takaaki Okazaki Ryuji 2023-03-21 Uracil in the carbonaceous asteroid (162173) Ryugu Nature Communications en 14 1 1292 10.1038/s41467-023-36904-3 36944653 2023NatCo..14.1292O 257641373 2041-1723 free 10030641 Similarities to CI chondrites NanoSIMS-based analysis at the Carnegie Institution found that the Ryugu samples contained grains older than the solar system. The abundance and composition of these presolar grains were similar when compared to presolar grains in CI chondrites.Barosch Jens Nittler Larry R. Wang Jianhua Alexander Conel M. O'D. De Gregorio Bradley T. Engrand Cécile Kebukawa Yoko Nagashima Kazuhide Stroud Rhonda M. Yabuta Hikaru Abe Yoshinari Aléon Jérôme Amari Sachiko Amelin Yuri Bajo Ken-ichi 2022-08-01 Presolar Stardust in Asteroid Ryugu The Astrophysical Journal 935 1 L3 10.3847/2041-8213/ac83bd 2208.07976 2022ApJ...935L...3B 251538946 0004-637X free Researchers using the particle accelerator in J-PARC, used Muon beams to analyse the chemical composition of the samples. The researchers found a similar composition when compared to CI chondrites, but a 25% lower oxygen abundance relative to silicon for the Ryugu samples. The oxygen excess in meteorites might come from contamination after they entered earth's atmosphere.2022-09-23 Researchers have used beams of muons to analyze the elemental composition of Asteroid Ryugu samples https://www.ipmu.jp/en/20220923-Ryugu 2022-09-28 Kavli IPMU-カブリ数物連携宇宙研究機構 en Magnetic field No magnetic field was detected near Ryugu on a global or local scale. This measurement is based on the magnetometer on board of MASCOT, which is called MasMag. This shows that Ryugu does not generate a magnetic field, indicating that the larger body from which it was fragmented was not generated in an environment with a strong magnetic field. This result cannot be generalized for C-type asteroids, however, because the surface of Ryugu seems to have been recreated in a catastrophic disruption.Hercik David Auster Hans-Ulrich Constantinescu Dragos Blum Jürgen Fornaçon Karl-Heinz Fujimoto Masaki Gebauer Kathrin Grundmann Jan-Thimo Güttler Carsten Hillenmaier Olaf Ho Tra-Mi 2020 Magnetic Properties of Asteroid (162173) Ryugu Journal of Geophysical Research: Planets en 125 1 e2019JE006035 10.1029/2019JE006035 2020JGRE..12506035H 2169-9100 free 1721.1/136097.2 free Surface features As of August 2019, there are 13 surface features that are named by the IAU.Jason Davis Hayabusa2 team sets date for sample collection, considers two touchdown sites Planetary.org January 16, 2019https://www.hayabusa2.jaxa.jp/en/topics/20190121e_Nomenclature/ Locations on the surface of Ryugu have been named! www.hayabusa2.jaxa.jp JAXA January 21, 2019 The three landing sites are not officially confirmed but are referred to by specific names in media by JAXA. The theme of features on Ryugu is "children's stories". Ryugu was the first object to introduce the feature type known as the saxa, referring to the large boulders found on Ryugu's surface. Craters Feature Named after Brabo Silvius Brabo Cendrillon Cendrillon Kibidango Kibidango featured in Momotaro Kintaro Kintarou, the child with super strength who grew up on Mount Ashigara Kolobok Kolobok Momotarou Momotarou Urashima Urashima Taro Dorsa A dorsum is a ridge. There is a single dorsum on Ryugu. Feature Named after Ryujin Dorsum Ryujinhttps://planetarynames.wr.usgs.gov/Feature/15780 USGS RYUGU – Ryujin Dorsum January 23, 2026 Fossae A fossa is a ditch-like feature. Feature Named after Horai Fossa Horai Tokoyo Fossa Tokoyo Saxa A saxum is a large boulder. Ryugu is the first astronomical object with them being named. Two boulders have been named "Styx" and "Small Styx" unofficially by the JAXA team; it is unknown if these names will be submitted for IAU approval. Both names refer to the River Styx.July 8, 2019. What's new http://www.hayabusa2.jaxa.jp/en/topics/20190708e_PPTD_approach2/ JAXA Hayabusa2 project 7 September 2019 ja Feature Named after Catafo Saxum Catafo, from Cajun folktales Ejima Saxum Ejima, the location where Urashima Taro rescued the turtle Otohime Saxum Otohime Landing sites JAXA has given informal names to the specific landing and collection sites. Feature Named after Notes Alice's Wonderland Alice in Wonderland MASCOT landing site Tritonis Lake Tritonis MINERVA-II1 landing site, initially referred to as "Trinitas"; as of February 2019 this has been rectified.February 2, 2019 Correction to the name of the MINERVA-II1 landing site. https://www.hayabusa2.jaxa.jp/en/topics/20190204e_Nomenclature/ www.hayabusa2.jaxa.jp JAXA January 24, 2026 Tamatebako Tamatebako Site of first sample collection Uchide-no-Kozuchi Uchide no kozuchi Site of second sample collectionJanuary 2026 Exploration Hayabusa2 mission Hayabusa2 thumb|left|Animation of Hayabusa2 orbit from 3 December 2014magenta Hayabusa2 lime 162173 Ryugu royalblue Earth yellow Sun The Japan Aerospace Exploration Agency (JAXA) spacecraft Hayabusa2 was launched in December 2014 and successfully arrived at the asteroid on 27 June 2018. It returned material from the asteroid to Earth in December 2020. The Hayabusa2 mission includes four rovers with various scientific instruments. The rovers are named HIBOU (aka Rover-1A), OWL (aka Rover-1B), MASCOT and Rover-2 (aka MINERVA-II-2). On 21 September 2018, the first two of these rovers, HIBOU and OWL (together the MINERVA-II-1 rovers) which hop around the surface of the asteroid, were released from Hayabusa2. This marks the first time a mission has completed a successful landing on a fast-moving asteroid body. On 3 October 2018, the German-French Mobile Asteroid Surface Scout (MASCOT) lander successfully arrived on Ryugu, ten days after the MINERVA rovers landed. Its mission was short-lived, as was planned; the lander had only 16 hours of battery power and no way to recharge. Hayabusa2 touched down briefly on February 22, 2019, on Ryugu, fired a small tantalum projectile into the surface to collect the cloud of surface debris within the sampling horn, and then moved back to its holding position.Touchdown: Japan probe Hayabusa2 lands on distant asteroid. Kyoko Hasegawa, PhysOrg. February 22, 2019. The second sampling was from the subsurface, and it involved firing a large copper projectile from an altitude of 500 metres to expose pristine material. After several weeks, it touched down on 11 July 2019 to sample the subsurface material, using its sampler horn and tantalum bullet.https://english.kyodonews.net/news/2019/07/c0805c17b10c-urgent-data-suggests-japans-hayabusa2-has-touched-down-on-asteroid.html Hayabusa2 successfully collects 1st-ever subsurface samples: JAXA Kyodo News 11 July 2019 15 July 2019 thumb|Samples of Ryugu returned by Hayabusa2Yada T, Abe M, Okada T, etal Preliminary analysis of the Hayabusa2 samples returned from C-type asteroid Ryugu Nature Astronomy 6 214–220 2022 2 10.1038/s41550-021-01550-6 245366019 free The last rover, Rover-2 or MINERVA-II-2, failed before release from the Hayabusa2 orbiter. It was deployed anyway on 2 October 2019 in orbit around Ryugu to perform gravitational measurements. It impacted the asteroid a few days after release. On 13 November 2019, commands were sent to Hayabusa2 to leave Ryugu and begin its journey back to Earth. On 6 December 2020 (Australian time), a capsule containing the samples landed in Australia and after a brief search was retrieved.Chang Kenneth Japan's Journey to an Asteroid Ends With a Hunt in Australia's Outback – The Hayabusa2 mission cements Japan's role in exploring the solar system, but finding its asteroid cargo presents one last challenge. https://www.nytimes.com/2020/12/05/science/japan-asteroid-hayabusa2-woomera.html 5 December 2020 The New York Times 5 December 2020 Rincon Paul Hayabusa-2: Capsule with asteroid samples in 'perfect' shape https://www.bbc.com/news/science-environment-55201662 6 December 2020 BBC News 6 December 2020 Prior to the sample capsule return, the amount of sample was expected to be at least 0.1 g.https://curation.isas.jaxa.jp/curation/hayabusa2/index.html Hayabusa2 Project Astromaterials Science Research Group, Extraterrestrial Sample Curation Center, JAXA 10 December 2020 https://web.archive.org/web/20180925215958/https://curation.isas.jaxa.jp/curation/hayabusa2/index.html 25 September 2018 The description of overall bulk sample was planned to be done by JAXA in the first six months.安部 正真 橘 省吾 小林 桂 伊藤 元雄 渡邊 誠一郎 ja:火の鳥「はやぶさ」未来編 その20 ～小惑星リュウグウからの リターンサンプル分析の全体像～ ja 日本惑星科学会誌遊星人 29 1 28–37 2020 10.14909/yuseijin.29.1_28https://fanfun.jaxa.jp/countdown/hayabusa2/press/files/20201208_hayabusa2_1208-2.pdf ja ja:はやぶさ2試料の初期記載・分析 JAXA Astromaterials Science Research Group JAXA 10 December 2020http://www.hayabusa2.jaxa.jp/enjoy/material/press/Hayabusa2_Press_20201116_ver11_en2.pdf Asteroid explorer, Hayabusa2, reporter briefing 16 November 2020 ((JAXA Hayabusa2 Project)) JAXA 10 December 2020 5 wt% of the sample will be allocated for the detailed analysis by JAXA. 15 wt% will be allocated for initial analysis, and 10 wt% for "phase 2" analysis among Japanese research groups. Within a year, NASA (10 wt%) and international "phase 2" research groups (5 wt%) will receive their allotment. 15 wt% will be allocated for research proposals by international Announcement of Opportunity. 40 wt% of the sample will be stored unused for future analysis. After the sample capsule returned, the amount of retrieved sample turned out to be about 5.4 g. Since it was 50 times more than anticipated, the allotment plan was adjusted to: 2 wt% to the detailed analysis by JAXA; 6 wt% for the initial analysis; 4 wt% for the "phase 2" analysis by Japanese research groups; 10 wt% for NASA; 2 wt% for the international "phase 2" research groups; 1 wt% for the public outreach; 15 wt% for the international Announcement of Opportunity; and the remaining 60 wt% will be preserved for future analysis.https://news.mynavi.jp/article/20210619-1907151/ Japanese ja:はやぶさ2の帰還サンプル、JAXA外部機関8チームでの分析が開始へ 19 June 2021 TECH+ Minoru Ōtsuka 20 June 2021https://www.hayabusa2.jaxa.jp/enjoy/material/press/Hayabusa2_Press_20210617_ver6.pdf Japanese ja:小惑星探査機「はやぶさ２」記者説明会 JAXA 17 June 2021 20 June 2021 June 2026 InternetArchiveBot In popular culture 162173 Ryugu is the setting of Daniel Suarez's novel Delta-V, describing the adventures of eight space miners who explore near-Earth asteroid Ryugu. See also List of minor planets and comets visited by spacecraft 101955 Bennu References Citations 2016-08-09 last obs. JPL Small-Body Database Browser: 162173 Ryugu (1999 JU3) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2162173 Jet Propulsion Laboratory 30 October 2018 162173 Ryugu (1999 JU3) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=162173 30 October 2018 MPC/MPO/MPS Archive Minor Planet Center https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html 30 October 2018 Name Selection of Asteroid 1999 JU3 Target of the Asteroid Explorer "Hayabusa2" JAXA 5 October 2015 http://global.jaxa.jp/press/2015/10/20151005_ryugu.html 30 October 2018 Current status of the asteroid explorer, Hayabusa2, leading up to arrival at asteroid Ryugu in 2018 14 June 2016 JAXA http://global.jaxa.jp/projects/sat/hayabusa2/pdf/Hayabusa2_Press20180614e.pdf 30 October 2018 From a distance of about 700km, Ryugu's rotation was observed 16 June 2016 JAXA http://www.hayabusa2.jaxa.jp/topics/20180616je/index_e.html 30 October 2018 Operation status for the asteroid explorer, Hayabusa2, in the vicinity of Ryugu 5 September 2018 JAXA http://global.jaxa.jp/projects/sat/hayabusa2/pdf/20180905_hayabusa2_e.pdf 30 October 2018 Yoshimitsu Tetsuo Kubota Takashi Tsuda Yuichi Yoshikawa Makoto MINERVA-II1: Successful image capture, landing on Ryugu and hop! JAXA 23 September 2015 http://www.hayabusa2.jaxa.jp/en/topics/20180922e/ JAXA Hayabusa2 Project 30 October 2018 Clark Stephen Hayabusa 2 team sets dates for asteroid landings – Spaceflight Now 6 September 2018 https://spaceflightnow.com/2018/09/06/hayabusa-2-team-sets-dates-for-asteroid-landings/ spaceflightnow.com 7 September 2018 Wall Mike Japanese Probe Deploys Tiny Hopping Robots Toward Big Asteroid Ryugu 21 September 2018 https://www.space.com/41898-hayabusa2-deploys-hopping-robots-asteroid-ryugu.html space.com 30 October 2018 Touchdown! Japan space probe lands new robot on asteroid 3 October 2018 phys.org https://phys.org/news/2018-10-japanese-spacecraft-device-asteroid.html 30 October 2018 Plait Phil Asteroid Ryugu Starts to Come Into Focus 20 June 2018 SyFy Wire https://www.syfy.com/syfywire/asteroid-ryugu-starts-to-come-into-focus 30 October 2018 6 M. Abe K. Kawakami S. Hasegawa D. Kuroda M. Yoshikawa T. Kasuga K. Kitazato Y. Sarugaku D. Kinoshita S. Miyasaka S. Urakawa S. Okumura Y. Takagi N. Takato T. Fujiyoshi H. Terada T. Wada Y. Ita F. Vilas R. P. Weissman March 2008 Ground-based Observational Campaign for Asteroid 162173 1999 JU3 https://www.lpi.usra.edu/meetings/lpsc2008/pdf/1594.pdf Lunar and Planetary Science 1391 37th COSPAR Scientific Assembly 1594 2008LPI....39.1594A 30 October 2018 6 T. G. Müller J. Durech M. Ishiguro M. Mueller T. Krühler H. Yang M.-J. Kim L. O'Rourke F. Usui C. Kiss B. Altieri B. Carry Y.-J. Choi M. Delbo J. P. Emery J. Greiner S. Hasegawa J. L. Hora F. Knust D. Kuroda D. Osip A. Rau A. Rivkin P. Schady J. Thomas-Osip D. Trilling S. Urakawa E. Vilenius P. Weissman P. Zeidler March 2017 Hayabusa-2 mission target asteroid 162173 Ryugu (1999 JU3): Searching for the object's spin-axis orientation Astronomy and Astrophysics 599 25 2017A&A...599A.103M 10.1051/0004-6361/201629134 free 1611.05625 73519172 6 Myung-Jin Kim Young-Jun Choi Hong-Kyu Moon Masateru Ishiguro Stefano Mottola Murat Kaplan Daisuke Kuroda Dhanraj S. Warjurkar Jun Takahashi Yong-Ik Byun February 2013 Optical observations of NEA 162173 (1999 JU3) during the 2011–2012 apparition Astronomy and Astrophysics 550 4 2013A&A...550L..11K 10.1051/0004-6361/201220673 free 1302.4542 54684944 6 S. Hasegawa T. G. Müller K. Kawakami T. Kasuga T. Wada Y. Ita N. Takato H. Terada T. Fujiyoshi M. Abe December 2008 Albedo, Size, and Surface Characteristics of Hayabusa-2 Sample-Return Target 162173 1999 JU3 from AKARI and Subaru Observations Publications of the Astronomical Society of Japan 60 SP2 S399––S405 2008PASJ...60S.399H 10.1093/pasj/60.sp2.S399 free 6 H. Campins J. P. Emery M. Kelley Y. Fernández J. Licandro M. Delbó A. Barucci E. Dotto August 2009 Spitzer observations of spacecraft target 162173 (1999 JU3) Astronomy and Astrophysics 503 2 L17–L20 2009A&A...503L..17C 10.1051/0004-6361/200912374 free 0908.0796 16329091 Liang-Liang Yu Jiang-Hui Ji Su Wang July 2014 Investigation of Thermal Inertia and Surface Properties for Near-earth Asteroid (162173) 1999 JU3 Chinese Astronomy and Astrophysics 38 3 317–329 2014ChA&A..38..317Y 10.1016/j.chinastron.2014.07.008 1805.05244 119186039 General references Vilas F. 2008 Spectral Characteristics of Hayabusa 2 Near-Earth Asteroid Targets 162173 1999 Ju3 and 2001 Qc34 Astronomical Journal 135 4 1101–1105 2008AJ....135.1101V 10.1088/0004-6256/135/4/1101 free 18–20 May 2009 International Symposium Marco Polo and other Small Body Sample Return Missions: Programme and Presentations http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=43784 European Space Agency 6 Nicholas A. Moskovitz Shinsuke Abe Kang-Shian Pan David J. Osip Dimitra Pefkou Mario D. Melita Mauro Elias Kohei Kitazato Schelte J. Bus Francesca E. DeMeo Richard P. Binzel Paul A. Abell May 2013 Rotational characterization of Hayabusa II target Asteroid (162173) 1999 JU3 Icarus 224 1 24–31 2013Icar..224...24M 10.1016/j.icarus.2013.02.009 1302.1199 118517193 External links MASCOT related publications by the Institute of Planetary Research https://web.archive.org/web/20201130081901/http://europlanet.dlr.de/Hayabusa2/MASCOT/index.html 30 November 2020 contains related images and 3D models of the surface of Ryugu 162173 162173 Ryugu 162173 162173 Astronomy Stars Spaceflight Solar System 162173 19990510 162173 162173 20180627 Category:Named minor planets 162173