  We analyze here a wide sample of carbonaceous chondrites from historic falls
(e.g. Allende, Cold Bokkeveld, Kainsaz, Leoville, Murchison, Murray and
Orgueil), and from NASA Antarctic collection in order to get clues on the role
of aqueous alteration in promoting the reflectance spectra diversity evidenced
in the most primitive chondrite groups. We particularly focus in the
identification of spectral features and behavior that can be used to remotely
identify primitive carbonaceous asteroids. The selected meteorite specimens are
a sample large enough to exemplify how laboratory reflectance spectra of rare
groups of carbonaceous chondrites exhibit distinctive features that can be used
to remotely characterize the spectra of primitive asteroids. Our spectra cover
the full electromagnetic spectrum from 0.2 to 25 microns by using two
spectrometers. First one is a UV-NIR spectrometer that covers the 0.2 to 2
microns window, while the second one is an Attenuated Total Reflectance IR
spectrometer covering the 2 to 25 microns window. In particular, laboratory
analyses in the UV-NIR window allow obtaining absolute reflectance by using
standardized measurement procedures. We obtained reflectance spectra of
specimens belonging to the CI, CM, CV, CR, CO, CK, CH, R, and CB groups of
carbonaceous chondrites plus some ungrouped ones, and allows identifying
characteristic features and bands for each class, plus getting clues on the
influence of parent body aqueous alteration. These laboratory spectra can be
compared with the remote spectra of asteroids, but the effects of terrestrial
alteration forming (oxy)hydroxides need to be considered.

Earth and Planetary Astrophysics;Instrumentation and Methods for Astrophysics