Influence of surface temperature on optical spectra of mafic materials

Abstract

Laboratory spectral reflectance measurements used to support interpretation of remote sensing data are usually performed at room temperature. However, surface temperatures of remotely sensed solar system bodies may vary significantly. Here we will review laboratory experiments performed at low and elevated temperatures. The results show that near-infrared reflectance spectra of mafic mineral assemblages are significantly affected by surface temperature. Surface temperature variations cause changes in shape and wavelength positions of diagnostic absorption bands in the NIR spectra of common mafic rock-forming minerals and their mixtures. Temperature-dependent effects should be taken into account when interpreting NIR remote sensing spectra of planetary surfaces, e.g., the data which will be obtained by the SIR instrument onboard the European SMART-1 spacecraft.