¹Zuriñe Yoldi,¹Antoine Pommerol,^1,2Olivier Poch,¹Nicolas Thomas
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2020.114169]
¹Physikalisches Institut, Universität Bern and NCCR PlanetS, Sidlerstrasse 5, 3012 Bern, Switzerland
²Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
Copyright Elsevier

The reflectance of water ice and dust mixtures depends, amongst other parameters, on how the components are mixed (e.g. intimate mixture, areal mixture or coating) (Clark, 1999). Therefore, when inverting the reflectance spectra measured from planetary surfaces to derive the amount of water ice present at the surface, it is critical to distinguish between different mixing modes of ice and dust. However, the distinction between mixing modes from reflectance spectra remains ambiguous. Here we show how to identify some water ice/soil mixing modes from the study of defined spectral criteria and colour analysis of laboratory mixtures. We have recreated ice and dust mixtures and found that the appearance of frost on a surface increases its reflectance and flattens its spectral slopes, whereas the increasing presence of water ice in intimate mixtures mainly impacts the absorption bands. In particular, we provide laboratory data and a spectral anal