METEORITES

This portion of the spectral library contains infrared (2.08-25 micrometer) 
bidirectional reflectance spectra of 60 powdered stony meteorite samples 
representing 50 different meteorites.  These spectra show that most powdered 
meteorite samples have undergone alteration, even if exposed only to water 
vapor in the air, and many have been contaminated by volatile hydrocarbons 
characterized by absorption bands near 3.45 micrometers (Salisbury et al., 
1991).  This hydrocarbon contamination is particularly important in view of the 
recent claims of an extraterrestrial origin for such volatile (PAH) hydrocarbons 
in 
Martian meteorites.  Evidence presented in Salisbury et al. (1991) and in 
Salisbury and Hunt (1974) strongly suggests that the primary macromolecular 
hydrocarbons in meteorites, including carbonaceous chondrites, do not display 
the 3.45 micrometer bands characteristic of aromatic hydrocarbons, or, in fact, 
any other detectable spectral features in their infrared spectra.  Powdered 
meteorites do, however, display a variety of other spectral features 
(reststrahlen 
bands, absorption bands, and Christiansen features) related to their mineralogy 
that can be used for their identification and for comparison with the infrared 
spectra of asteroids (Salisbury et al., 1991).


REFERENCES

Salisbury, J. W., D'Aria, D. M., and Jarosewich, E. J., 1991, Midinfrared (2.5-
13.5 
micrometer) reflectance spectra of powdered stony meteorites: Icarus, v. 92, p. 
280-297.

Salisbury, J. W., and Hunt, G. R., 1974, Meteorite spectra and weathering: J. of 
Geophys. Res., v. 79, p. 4439-4441.