Precise reflectante spectra of ordinary chondrites in the visible and uv : exploring the variability of s-class asteroidal spectra

Abstract

Narrow-band spectrophotometry programs for the study of asteroids were initiated in the 1960s [1,2], which were able to identify clear absorption bands in the UV and visible, that were used later on in order to develop the first asteroid taxonomy [3]. A step forward was to remotely obtain reflectance spectra of asteroids to establish the existence of families [4, 5, 6], and to place meteorites broadly within these families based on their own spectra. This approach is imperfect due to space weathering, that together with the presence of regolith, intrinsic roughness, etc., alters the reflectance spectra to be compared with spectra of meteorites in our laboratories. Currently there are several comprehensive spectral catalogue of meteorites [7-8], but we wish to explore the capacities of current spectrographs to obtain reflectivities in those extreme regions of the electromagnetic spectrum where data is poor (typically below 0.4 microns and over 2.4 microns). Additionally we wish to explore the importance of roughness as the reason for the diverse mineralogy observed for S-class asteroids that are linked to the ordinary chondrites [9].