Author: Z. Kanuchova

Title: 
STUDY OF THE AGEING AND REJUVENATING PROCESSES AFFECTING 25143 ITOKAWA


Abstract:
The collection of the high resolution images of Itokawa achieved by
Asteroid Multiband Imaging CAmera (AMICA) and Near Infrared Spectrometer
(NIRS) of the Hayabusha mission revealed high heterogenity in color and
albedo of Itokawa.Variations in color and albedo were found to be similar
as those observed at LL (LL6) chondrites when altered by SW processes. We
have studied the distribution of spectral characteristics of asteroid 25143
Itokawa surface to understand the ongoing space weathering and rejuvenation
processes. The results of our own ion and laser irradiation experiments of
materials relevant to the surface of Itokawa, as well as data published in
the RELAB database were used for the models of Itokawa surface spectra
distribution observed by Hayabusha AMICA. Two competing proceses – ageing
and rejuvenating of the surface – are considered in the models. The first
results are presented.