Japan Geoscience Union Meeting 2018

Presentation information

[EE] Poster

P (Space and Planetary Sciences) » P-PS Planetary Sciences

[P-PS03] Small Bodies in the Solar System: Current Understanding and Future Prospects

Wed. May 23, 2018 10:45 AM - 12:15 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Masateru Ishiguro(Department of Physics and Astronomy, Seoul National University), Taishi Nakamoto(Tokyo Institute of Technology), Masahiko Arakawa(神戸大学大学院理学研究科, 共同), Masanao Abe(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency)

[PPS03-P14] Optical spectra of (25143) Itokawa via Hayabusa/AMICA observation

*Sunho Jin1, Masateru Ishiguro1 (1.Seoul National University)

Keywords:Asteroid, Itokawa, Hayabusa, Space Weathering

Understanding of space weathering effect is important since it provides a clue to the evolution scenario of target asteroids. The near-Earth asteroid (25143) Itokawa shows a diverse of spectral properties in Hayabusa/AMICA images, suggesting a various degree of space weathering on the surface. It is known that the space weathering changes the spectra of silicaceous asteroids redder, eliminating the absorption around 1 μm. Taking the advantage of the availability of AMICA at 0.38-1.01 μm, we contrive to derive the spectra at different terrains on Itokawa. It is, however, reported that the scattered light components severely degrade the AMICA images, especially at the wavelengths >0.86 μm. Here we upgraded a technique introduced in Ishiguro (2014) using a simplex technique for the subtraction of scattered light components, and derive the spectra using full set of AMICA seven channels. Our new technique enables to apply for the longest channel (i.e., zs-band at 1.01 μm) images. From these reflectance spectra, we tentatively estimated the surface ages at the different location to be 0.8-2 Myr. Based on this data together with results in previous publications, we shall discuss about the evolutional scenario of this asteroid.