scholarly journals Preliminary analysis of the Hayabusa2 samples returned from C-type asteroid Ryugu

2021 ◽  
Author(s):  
Toru Yada ◽  
Masanao Abe ◽  
Tatsuaki Okada ◽  
Aiko Nakato ◽  
Kasumi Yogata ◽  
...  
Keyword(s):  
Solar System ◽  
Size Distribution ◽  
Near Infrared ◽  
Chemical Properties ◽  
Textural Properties ◽  
Ground Truth ◽  
Building Blocks ◽  
Bulk Sample ◽  
Near Infrared Reflectance ◽  
Origin And Evolution

AbstractC-type asteroids1 are considered to be primitive small Solar System bodies enriched in water and organics, providing clues to the origin and evolution of the Solar System and the building blocks of life. C-type asteroid 162173 Ryugu has been characterized by remote sensing2–7 and on-asteroid measurements8,9 with Hayabusa2 (ref. 10). However, the ground truth provided by laboratory analysis of returned samples is invaluable to determine the fine properties of asteroids and other planetary bodies. We report preliminary results of analyses on returned samples from Ryugu of the particle size distribution, density and porosity, spectral properties and textural properties, and the results of a search for Ca–Al-rich inclusions (CAIs) and chondrules. The bulk sample mainly consists of rugged and smooth particles of millimetre to submillimetre size, confirming that the physical and chemical properties were not altered during the return from the asteroid. The power index of its size distribution is shallower than that of the surface boulder observed on Ryugu11, indicating differences in the returned Ryugu samples. The average of the estimated bulk densities of Ryugu sample particles is 1,282 ± 231 kg m−3, which is lower than that of meteorites12, suggesting a high microporosity down to the millimetre scale, extending centimetre-scale estimates from thermal measurements5,9. The extremely dark optical to near-infrared reflectance and spectral profile with weak absorptions at 2.7 and 3.4 μm imply a carbonaceous composition with indigenous aqueous alteration, matching the global average of Ryugu3,4 and confirming that the sample is representative of the asteroid. Together with the absence of submillimetre CAIs and chondrules, these features indicate that Ryugu is most similar to CI chondrites but has lower albedo, higher porosity and more fragile characteristics.

scholarly journals Ryugu: A brand-new planetary sample returned from a C-type asteroid

2021 ◽  
Author(s):  
Toru Yada ◽  
Masanao Abe ◽  
Tatsuaki Okada ◽  
Aiko Nakato ◽  
Kasumi Yogata ◽  
...  
Keyword(s):  
Solar System ◽  
Near Infrared ◽  
Chemical Properties ◽  
Building Blocks ◽  
Bulk Sample ◽  
Near Infrared Reflectance ◽  
Origin And Evolution ◽  
Thermal Measurements ◽  
Solar System Bodies ◽  
Physical And Chemical

Abstract C-type asteroids are considered to be primitive small Solar-System bodies enriched in water and organics, providing clues for understanding the origin and evolution of the Solar System and the building blocks of life. C-type asteroid 162173 Ryugu has been characterized by remote sensing and on-asteroid measurements with Hayabusa2, but further studies are expected by direct analyses of returned samples. Here we describe the bulk sample mainly consisting of rugged and smooth particles of millimeter to submillimeter size, preserving physical and chemical properties as they were on the asteroid. The particle size distribution is found steeper than that of surface boulders11. Estimated grain densities of the samples have a peak around 1350 kg m-3, which is lower than that of meteorites suggests a high micro-porosity down to millimeter-scale, as estimated at centimeter-scale by thermal measurements. The extremely dark optical to near-infrared reflectance and the spectral profile with weak absorptions at 2.7 and 3.4 microns implying carbonaceous composition with indigenous aqueous alteration, respectively, match the global average of Ryugu, confirming the sample’s representativeness. Together with the absence of chondrule and Ca-Al-rich inclusion of larger than sub-mm, these features indicate Ryugu is most similar to CI chondrites but with darker, more porous and fragile characteristics.

scholarly journals Thermography of Asteroid and Future Applications in Space Missions

2020 ◽  
Vol 10 (6) ◽  
pp. 2158
Author(s):  
Tatsuaki Okada
Keyword(s):  
Solar System ◽  
Small Body ◽  
Landing Site ◽  
Building Blocks ◽  
Space Missions ◽  
Origin And Evolution ◽  
Thermal Environments ◽  
Mission Success ◽  
Hazardous Object ◽  
Potential Applications

The Near-Earth Asteroid 162173 Ryugu is a C-type asteroid which preserves information about the ancient Solar System and is considered enriched in volatiles such as water and organics associated with the building blocks of life, and it is a potentially hazardous object that might impact Earth. Hayabusa2 is the asteroid explorer organized by the Japan Aerospace Exploration Agency to rendezvous with the asteroid and collect surface materials to return them to Earth. Thermography has been carried out from Hayabusa2 during the asteroid proximity phase, to unveil the thermophysical properties of the primitive Solar System small body, which offered a new insight for understanding the origin and evolution of the Solar System, and demonstrated the technology for future applications in space missions. Global, local, and close-up thermal images taken from various distances from the asteroid strongly contributed to the mission success, including suitable landing site selection, safe assessment during descents into the thermal environments and hazardous boulder abundance, and the detection of deployable devices against the sunlit asteroid surface. Potential applications of thermography in future planetary missions are introduced.

Prediction of Wheat Bread-Baking Functionality in Whole Kernels, Using near Infrared Reflectance Spectroscopy

1998 ◽  
Vol 6 (1) ◽  
pp. 121-127 ◽  
Author(s):  
Twylla Pawlinsky ◽  
Phil Williams
Keyword(s):  
Near Infrared ◽  
Chemical Properties ◽  
Wheat Bread ◽  
Test Procedures ◽  
Near Infrared Reflectance ◽  
Wet Chemistry ◽  
Whole Wheat ◽  
Large Numbers ◽  
Physico Chemical ◽  
Infrared Methods

Efficiency of prediction of wheat strength by “wet chemistry” prediction tests is summarised. Inter-relationships among these tests, and recognised criteria of wheat strength (physico-chemical properties and baking data) are reviewed. Calibrations for predicting both “prediction-type” and data from recognised test procedures have been developed for use with whole wheat. The relative efficiencies of near infrared and established wet chemistry methods for the prediction of wheat strength for use in plant-breeding are discussed. For screening large numbers of lines for several strength parameters, near infrared methods are more practicable.

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

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