Role of spectral resolution for infrared asteroid compositional analysis using meteorite spectra

Abstract

In this work the potential mineral identification of meteorites is analysed for the mid-infrared range, to evaluate observational possibilities for future missions targeting small body surfaces. Three carbonaceous and three ordinary chondrite meteorites are examined by a diffuse reflection (DRIFT) instrument, and the presence of principal minerals is confirmed by a powder diffraction method as well. The possibilities and constraints of mineral identifications in the mid-infrared are simulated by artificially degrading the spectral resolution. Our research shows that for the definite identification of principal mineral bands, a spectral resolution $\le 10$~cm${}^{-1}$ ($\le 0.15\hat{I}¼$m) is needed. At 20-100~cm${}^{-1}$ (0.3 - 1.5~$\hat{I}¼$m) resolution the identification of these minerals is uncertain, and with a resolution $>100$~cm${}^{-1}$, it is almost impossible.

Accepted in MNRAS for publication on May 22nd, 2020; 7 pages, 3 figures