Ryugu’s Anhydrous Ingredients and Their Spectral Link to Primitive Dust from the Outer Solar System

Abstract Ryugu is a second-generation C-type asteroid formed by the reassembly of fragments previous larger body in main belt. While majority samples returned Hayabusa2 are composed lithology dominated aqueously altered minerals, clasts pristine olivine and pyroxene remain least-altered lithologies. These objects great interest for revealing composition dust from which original building blocks Ryugu's parent formed. Here we show that some grains rich olivine, pyroxene, amorphous silicates discovered one millimeter-sized stone have infrared spectra similar to D-type Hektor (a Jupiter Trojan), comet Hale–Bopp, anhydrous interplanetary particles probable cometary origin. This result indicates primary incorporated ingredients asteroids (and possibly comets) outer solar system, retained valuable information on formation evolution planetesimals at different epochs our system's history.