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

TL;DR

This study evaluates how spectral resolution impacts the ability to identify minerals in meteorites using mid-infrared spectroscopy, highlighting the need for high resolution for accurate mineral detection in asteroid missions.

Contribution

It demonstrates the critical spectral resolution threshold needed for reliable mineral identification in meteorite spectra for asteroid surface analysis.

Findings

Spectral resolution ≤ 10 cm⁻¹ is required for definite mineral identification.

Identification becomes uncertain at 20-100 cm⁻¹ resolution.

Mineral identification is nearly impossible at resolutions >100 cm⁻¹.

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 $\leq 10$~cm$^{-1}$ ($\leq 0.15 \mu$m) is needed. At 20-100~cm$^{-1}$ (0.3 - 1.5~$\mu$m) resolution the identification of these minerals is uncertain, and with a resolution $>100$~cm$^{-1}$, it is almost impossible.