Global mapping of the degree of space weathering on asteroid 25143 Itokawa by Hayabusa/AMICA observations
Author
Ishiguro, M.Hiroi, T.
Tholen, D. J.
Sasaki, S.
Ueda, Y.
Nimura, T.
Abe, M.
Clark, B. E.
Yamamoto, A.
Yoshida, F.
Nakamura, R.
Hirata, N.
Miyamoto, H.
Yokota, Y.
Hashimoto, T.
Kubota, T.
Nakamura, A. M.
Gaskell, R. W.
Saito, J.
Issue Date
2007-01-01
Metadata
Show full item recordCitation
Ishiguro, M., Hiroi, T., Tholen, D. J., Sasaki, S., Ueda, Y., Nimura, T., ... & Saito, J. (2007). Global mapping of the degree of space weathering on asteroid 25143 Itokawa by Hayabusa/AMICA observations. Meteoritics & Planetary Science, 42(10), 1791-1800.Publisher
The Meteoritical SocietyJournal
Meteoritics & Planetary ScienceAdditional Links
https://meteoritical.org/Abstract
We obtained color images of near-Earth asteroid 25143 Itokawa by the Hayabusa multiband imaging camera to characterize the regional color properties. Images were obtained for the whole disk from the gate position (GP) and home position (HP) at a spatial resolution of 0.8-3.7 m/ pixel. Whole-disk spectra are adjusted to the telescopic data obtained by the University of Hawai'is 88-inch telescope using the Eight Color Asteroid Survey (ECAS) system. The disk-resolved measurements show large variations in the three visible channels. We present a map of an index related to the degree of space weathering, which has been newly developed based on laboratory measurements. We find large variations in the degree of space weathering on Itokawa. Fresh materials are observed in regions of steep slopes and craters, whereas mature materials are ubiquitously distributed. This result suggests that pristine ordinary chondrite-like materials have been exposed through weathered layers by excavation. By also examining close-up images obtained during touchdown rehearsal, we find that most rocks in Itokawas rough terrains are weathered. Instead of a regolith blanket, the surface of this small asteroid is covered with weathered rocks and gravels.Type
Articletext
Language
enISSN
1945-5100ae974a485f413a2113503eed53cd6c53
10.1111/j.1945-5100.2007.tb00538.x