Yuto Takei
A5028875127- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Space Satellite Systems and Control
- Geology and Paleoclimatology Research
- Geological and Geochemical Analysis
- Spacecraft Dynamics and Control
- Geophysics and Gravity Measurements
- High-pressure geophysics and materials
- Inertial Sensor and Navigation
- Astronomical Observations and Instrumentation
- GNSS positioning and interference
- Spacecraft and Cryogenic Technologies
- Geomagnetism and Paleomagnetism Studies
- Spacecraft Design and Technology
- Satellite Communication Systems
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Silicone and Siloxane Chemistry
- Modular Robots and Swarm Intelligence
- Nuclear Physics and Applications
- Opportunistic and Delay-Tolerant Networks
- Archaeology and ancient environmental studies
- Space Exploration and Technology
- Radiation Detection and Scintillator Technologies
Japan Aerospace Exploration Agency
2018-2024
Institute of Space and Astronautical Science
2018-2023
National Sagamihara Hospital
2019-2022
Chiba Institute of Technology
2014
The Hayabusa2 spacecraft arrived at the near-Earth carbonaceous asteroid 162173 Ryugu in 2018. We present observations of Ryugu's shape, mass, and geomorphology. has an oblate "spinning top" with a prominent circular equatorial ridge. Its bulk density, 1.19 ± 0.02 grams per cubic centimeter, indicates high-porosity (>50%) interior. Large surface boulders suggest rubble-pile structure. Surface slope analysis shows shape may have been produced from having once spun twice current rate. Coupled...
Hayabusa2 at the asteroid Ryugu Asteroids fall to Earth in form of meteorites, but these provide little information about their origins. The Japanese mission is designed collect samples directly from surface an and return them for laboratory analysis. Three papers this issue describe team's study near-Earth carbonaceous 162173 Ryugu, which spacecraft arrived June 2018 (see Perspective by Wurm). Watanabe et al. measured asteroid's mass, shape, density, showing that it a “rubble pile” loose...
The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. produced artificial crater with diameter >10 meters, semicircular shape, elevated rim, and central pit. Images of resulting ejecta were recorded by Deployable CAMera 3 for >8 minutes, showing growth curtain (the outer edge ejecta) deposition onto surface. was asymmetric heterogeneous it never fully detached...
Abstract C-type asteroids 1 are considered to be primitive small Solar System bodies enriched in water and organics, providing clues the origin evolution of building blocks life. asteroid 162173 Ryugu has been characterized by remote sensing 2–7 on-asteroid measurements 8,9 with Hayabusa2 (ref. 10 ). However, ground truth provided laboratory analysis returned samples is invaluable determine fine properties other planetary bodies. We report preliminary results analyses on from particle size...
Collecting a sample of asteroid Ryugu The Hayabusa2 spacecraft recently traveled to the nearby carbonaceous collect samples and return them Earth for laboratory analysis. Morota et al. describe Hayabusa2's first collection, taken during brief touchdown on Ryugu's surface. Close-up images video sampling process allowed authors investigate surface colors morphology small scale. Relating these craters stratigraphy constrains evolution Ryugu. conclude that experienced prior period strong solar...
Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned C-type asteroid Ryugu by Hayabusa2 mission. On average consist 50% phyllosilicate matrix, 41% porosity 9% minor phases, including organic matter. The abundances 70 elements in close agreement with those CI chondrites. Bulk show higher δ18O, Δ17O, ε54Cr values than As such, sampled most primitive least-thermally processed protosolar nebula reservoirs. Such finding is...
The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. mission performed two landing operations to collect samples of surface and subsurface material, latter exposed by an artificial impact. We present images second touchdown site, finding that ejecta from impact crater was at sample location. Surface pebbles both sites show morphological variations ranging rugged smooth, similar Ryugu's boulders, shapes quasi-spherical flattened. were returned Earth on 6...
Abstract Volatile and organic-rich C-type asteroids may have been one of the main sources Earth’s water. Our best insight into their chemistry is currently provided by carbonaceous chondritic meteorites, but meteorite record biased: only strongest types survive atmospheric entry are then modified interaction with terrestrial environment. Here we present results a detailed bulk microanalytical study pristine Ryugu particles, brought to Earth Hayabusa2 spacecraft. particles display close...
Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through collective process called space weathering. The return samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study space-weathering signatures on most abundant type inner solar system body: C-type asteroid, composed materials largely unchanged since formation...
The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples were retrieved by Hayabusa2 spacecraft. We measured noble gas and nitrogen isotopes in samples found they are dominated presolar primordial components, incorporated during Solar System formation. Noble concentrations higher than those Ivuna-type (CI) chondrite meteorites. Several host phases isotopically distinct have...
The Hayabusa2 spacecraft returned to Earth from the asteroid 162173 Ryugu on 6 December 2020. One day after recovery, gas species retained in sample container were extracted and measured on-site stored collection bottles. consists of helium neon with an extraterrestrial 3 He/ 4 He 20 Ne/ 22 Ne ratios, along some contaminant terrestrial atmospheric gases. A mixture solar Earth’s is best explanation for composition. Fragmentation grains within discussed basis estimated amount indigenous size...
Abstract Ryugu is a carbonaceous rubble-pile asteroid visited by the Hayabusa2 spacecraft. Small rubble pile asteroids record thermal evolution of their much larger parent bodies. However, recent space weathering and/or solar heating create ambiguities between uppermost layer observable remote-sensing and pristine material from body. observations find that on (162173) both north south pole regions preserve least processed weathering, which spectrally blue chondritic with 0–3% deep 0.7-µm...
This research focuses on the design and reconstruction of first touchdown Hayabusa2 asteroid Ryugu. Because plethora boulders, landing operation required high accuracy to ensure spacecraft safety. paper therefore investigates a pinpoint sequence using retroreflective marker as an artificial landmark. First, dynamical environment in vicinity Ryugu is explored for precise trajectory analyses; particularly, irregular gravitational field around computed, which has impact motion. Based dynamics...