  (1270) Datura is the largest member of a very young asteroid cluster that was
thought to be broken-up 0.45 Myr ago. The light-curve and the rotation-resolved
reflectance spectra (0.6 um - 1.0 um) were observed in order to find "fresh"
surface. Our data show no significant spectral variation along the rotation
phase. The depth of the 0.95 um absorption band, which indicates the degree of
space weathering, was similar to that of an old S-type asteroid. This suggests
that the reflectance spectrum in this wavelength range changes rapidly and
saturates the depth of the 0.95 um absorption in less than 0.45 Myr in the main
belt environment.
