Led by the Japan Aerospace Exploration Agency (JAXA), Hayabusa2 aimed to reveal the real nature of Ryugu and explore how astrologists can utilize knowledge from meteorites to analyze telescopic observations of other hydrous asteroids.Unlike meteorites obtained from comparable hydrous asteroids, the Ryugu samples prevented terrestrial modification– the interaction with oxygen and water in the Earths atmosphere.Optical images of the Ryugu sample (left) and the CI chondrite (Orgueil; right). The group successfully established analytical procedures that prevented exposing the samples to Earths atmosphere, ensuring the conservation of their initial conditions.Challenging Previous AssumptionsPrevious studies suggested that Ryugus sample mineralogy looked like CI chondrites, the most primitive meteorites chemically. Further investigations in the new study indicated that heating CI samples under lowering conditions at 300 ° C recreated Ryugus sample mineralogy well, resulting in spectra closely matching those of Ryugu samples.The reflectance spectra of Ryugu sample (blue line), unheated CI sample (black, dotted line), and the CI sample heated up at 300 ° C. Modified from Figure 5A in Amano et al. (2023 ).