Variations of the surface characteristics of Ryugu returned samples

Abstract Hayabusa2 spacecraft successfully collected rock samples from the surface of C-type near-Earth asteroid 162173 Ryugu through two touchdowns and brought them back to Earth in 2020. At Extraterrestrial Sample Curation Center JAXA, we performed initial description all obtain fundamental information prepare database for sample allocation. We propose morphological classifications returned based on 205 grains described first 6 months. The can be distinguished by four characteristics: dark, glossy, bright, white. According coordinated study provide an detailed investigation scanning electron microscopy X-ray diffraction analysis this study, these features reflect differences degree space weathering mineral assemblages. studied grain types is heterogeneous: weak A0042 (dark group) C0041 (white group); moderate C0094 (glossy); severe A0017 (bright). white phase, which characteristic group grains, identified as large carbonate minerals. This effort classify into distinct categories. Based results, researchers estimate characteristics only JAXA curation public database. It will important reference selection further investigation. Graphical