I'm looking forward to this Mars Express experiment:

DISCRIMINATION BETWEEN SOLID, LIQUID AND GASEOUS H2O, AND
ASSESSMENT OF H2O TEMPERATURE BY SPECTROSCOPY USING THE OMEGA
IMAGING SPECTROMETER (MARS EXPRESS). Bernard SCHMITT1, Sylvain DOUTÉ1,
Stéphane ERARD2, Yves LANGEVIN2, Jean-Pierre BIBRING2. 1Laboratoire de Planétologie de
Grenoble, CNRS - Université J. Fourier, France; 2Institut d’Astrophysique Spatiale, CNRS -
Université Paris-Sud, Orsay, France.
The OMEGA imaging spectrometer (PI: JP.
Bibring, IAS) of the European Mars
Express mission will map in the visible and
near-infrared (0.5–5.2 µm) various mineral
and volatile species at the surface of Mars
during one or two Martian years. In particular
OMEGA should be able to: 1) discriminate
between the different phases of H2O: ice,
liquid, gas, mixed with CO2, adsorbed,
hydratation,... 2) map their spatial distribution
and 3) monitor their diurnal and seasonal
changes. This may thus provide very useful
information about the water cycle on Mars
and its relationship with the atmosphere,
surface and aerosols.
In this talk we will first present the optical
constants of H2O ice and liquid water
recorded in the near-infrared as a function of
temperature (Grundy and Schmitt 1998,
Schmitt et al. 1998). Then, using a radiative
transfer model in layered surfaces (Douté and
Schmitt 1998) we will show how the various
phases of H2O (ice, liquid, gas, diluted in
CO2 ice) mixed with CO2 ice or minerals
could be discriminated with OMEGA For that
purpose we will consider different
coexistence modes of the previous
compounds: intimate mixtures, stratification,
etc.
Finally we will assess the capability of
OMEGA to determine the temperature of H2O
ice using the temperature dependent behavior
of several of its absorption features (Grundy
and Schmitt 1998, Grundy et al. 1999). This
capability should be of great interest,
especially for surface temperature below
180K, below which OMEGA is not sensitive
to thermal emission. As a result, temperature
maps of the polar caps will be obtained
throughout the year (except winter).
Additionally, analysis of the OMEGA data
should lead to the temperature of cold ice
patches mixed under the pixel scale with
hotter minerals dominating thermal emission.
References: DOUTÉ, S., and B.
SCHMITT 1998. A multi-layer bidirectional
reflectance model for the analysis of planetary
surface hyperspectral images at visible and
near infrared wavelengths. J. Geophys. Res.
E, 103, 31,367–31,390. GRUNDY, W., and
B. SCHMITT 1998. The temperaturedependent
near-infrared absorption spectrum
of hexagonal H2O ice. J. Geophys. Res. E,
103, 25809–25822. GRUNDY, W.M., M.W.
BUIE, J.A. STANSBERRY, J.R. SPENCER
and B. SCHMITT 1999. Near-infrared spectra
of icy outer solar system surfaces: Remote
determination of H2O ice temperatures.
Icarus, 142, 536–549. SCHMITT, B., E.
QUIRICO, F. TROTTA, and W. GRUNDY
1998. Optical properties of ices from UV to
infrared. In Solar System Ices, (B. Schmitt, C.
de Bergh, and M. Festou eds.) Kluwer
Academic Publ., Dordrecht, Astrophys. Space
Sci. Lib., Vol. 227, pp. 199–240

From page 45 of this workshop report:

MARS INFRARED SPECTROSCOPY: FROM THEORY AND THE LABORATORY TO FIELD
OBSERVATIONS.
June 4-6, 2002 at the Lunar and Planetary Institute.
LPI Mars Spectral Workshop II (2002).
http://www.lpi.usra.edu/science/kirkland/Workshop2/report_workshop2.pdf

Bob Clark