Itokawa SamplesItokawa Samples The JAXA Hayabusa spacecraft collected samples by touching down on the 500-meter long asteroid Itokawa. Itokawa particles (largest was 300  m) were collected using (A) an electrostatic needle, (B) a Teflon spatula, and (C) by thumping the container and collecting grains on a pure-silica glass slide.

Composition is Like an LL ChondriteComposition is Like an LL Chondrite Compositions of olivine (Fa) and pyroxene (Fs) in dust grains from Itokawa plot in the middle of the field defined by LL ordinary chondrites. Most are highly equilibrated, and also plot in the LL field. Identification as LL chondrite shows that S-asteroids, such as Itokawa, are composed of ordinary chondritic material, not differentiated rock.

Space Weathering on ItokawaSpace Weathering on Itokawa The surfaces of many grains from Itokawa show amorphous silica-rich deposits caused by space weathering. Regions identified in TEM imaging: I.Amorphous silicate with nanophase iron sulfide grains II.Partially amorphous region enriched in nanophase metallic iron grains III.Unaltered parent mineral (in this case, pyroxene)