Diurnal and Seasonal Mapping of Martian Ices With EMIRS

Condensation and sublimation of ices at the surface of the planet is a key part of both the Martian H$_2$O and CO$_2$ cycles, either from a seasonal or diurnal aspect. While most of the ice is located within the polar caps, surface frost is known to be formed during nighttime down to equatorial latitudes. Here, we use data from the Emirates Mars Infrared Spectrometer (EMIRS) onboard the Emirates Mars Mission (EMM) to monitor the diurnal and seasonal evolution of the ices at the surface of Mars over almost one Martian year. The unique local time coverage provided by the instrument allows us to observe the apparition of equatorial CO$_2$ frost in the second half of the Martian night around the equinoxes, to its sublimation at sunrise

OMEGA-Py: Python tools for OMEGA data

<h2>OMEGA-Py v3.0 - Official – Major updates</h2><p>From the release of version 3.0, OMEGA-Py has been officially validated by the OMEGA team and is distributed as an official OMEGA software alternative to the IDL version.</p><p>A complete online documentation has been written and is available at <a href="https://astcherbinine.github.io/omegapy/">https://astcherbinine.github.io/omegapy/</a></p><h3>Updates to the omega_data.OMEGAdata class</h3><ul><li>Improve binaries processing to have a perfect match with the IDL version of the code, force the use of float32 instead of float64</li><li>Add focal plane and spectrometer temperatures for all channels</li><li>Add incidence and emergence angles w.r.t. the local normal (in addition to the ellipsoid)</li><li>Add omega.ref_C, surface reflectance map to be compared with cos(inci_n) to check the geometry spatial calibration</li><li>Add geometry information for the V-channel (which is slightly different to the one of the V+L channels)</li><li>Add distance to Sun in km (in addition to a.u. value)</li></ul><h3>omega_plots</h3><ul><li>Add option to use the V-channel geometry in all the display functions that use projection (use_V_geom=True)</li></ul><h3>omega_data</h3><ul><li>Add option to filter only the data cubes acquired with nadir geometry in find_cube (nadir_only=True)</li></ul>If you use this software, please cite it using the metadata from this file

SPiP : Spacecraft Pixel footprint Projection

<h1>SPiP v1.2</h1> <h2>Main updates</h2> <ul> <li>Downgrade requirements to Python >= 3.6</li> <li>Fix errors in <code>multi_px_projection</code></li> <li>Fix issue on θ value if Δlat or Δpx is 0</li> </ul>If you use this software, please cite it using the metadata from this file

On the Origin of the Increase of the Surface Aqueous Alteration in the Martian Polar Regions

International audienceWe present different hypotheses that we plan to investigate in order to study the observed increase of the surface hydration level in the martian polar regions

Martian surface aqueous alteration from the study of the combined evolution of the 1.9 and 3 microns band with OMEGA

International audienc

Identification of a new spectral signature at 3 µm over Martian northern high latitudes: implications for surface composition

International audienceMars northern polar latitudes are known to harbor an enhanced 3 µm spectral signature when observed from orbit. This may indicate a greater amount of surface adsorbed or bound water, although it has not yet been possible to easily reconcile orbital observations with ground measurements by Phoenix. Here we reprocessed OMEGA/Mars Express observations acquired during the Northern summer to further characterize this 3 µm absorption band increase. We identify the presence of a new specific spectral signature composed of an additional narrow absorption feature centered at 3.03 µm coupled with an absorption at ≥ 3.8 µm. This signature is homogeneously distributed over a bright albedo open ring surrounding the circumpolar low-albedo terrains between ∼ 68°N and 76°N and ∼ 0°E and 270°E. This location includes the Phoenix landing site. This feature shows no time variability and can be confidently attributed to a seasonally stable surface component. All together, the stability, spectral shape and absence of significant correlation with other signatures in the 1-2.5 µm range discard interpretations relying on water ice or easily exchangeable adsorbed water. The exact full spectral shape cannot be easily reproduced by pure minerals samples, although sulfates, notably lowly hydrated Ca-sulfates, provide interesting comparisons. A modification of the chemical or physical properties of the soil, potentially involving additional sulfates contaminants, or modification of the hydration state of sulfates, and/or modification of their grains size, seems a plausible explanation to this observation, which may then indicate geologically recent water alteration at high northern latitudes

Evidence of an Additional North Polar Component in the Martian 3 Microns Water Band Observed by OMEGA

International audienceWe present evidence for a new spectral component in the martian 3 microns water band that only appears under north polar latitudes, that may be of importance in the search for the origin of the strong polar increase of the surface aqueous alteration

Observational evidence for a dry dust-wind origin of Mars seasonal dark flows

Seasonal flows on warm slopes, or recurring slope lineae ("RSL"), have been presented as strong evidence for currently flowing water on Mars. This assumption was supported by a correlation between activity and warm temperatures, and by the spectral identification of hydrated salts. Here we first demonstrate that salts spectral identification is not robust, and that flow activity occurs on a wider range of seasons and slope orientations than previously thought, ruling out liquid water as a probable contributor. We then show that morphology, location and timing of flow activity is fully consistent with the removal and deposition of bright dust above darker underlying surfaces occurring notably in relation with seasonal dust storm activity. Mars recurring slope lineae are thus consistent with dust movements typical of present-day dry planet Mars