Mars

Spectral Evidence For Irradiated Halite On Mars

By Keith Cowing

Status Report

via PubMed

September 22, 2024

Filed under astrogeology, Biosignatures, chloride salt-bearing deposits, Halite, Mars, Pubmed, remotesensing, Spectroscopy

Spectral Evidence For Irradiated Halite On Mars — Chloride salt-bearing deposits. (a) True color and (b) chloride browse products for CRISM images FRT0000A858 and FRT0000B001. The true color image is an enhanced natural color representation of the scene, and the chloride browse product shows information related to inferred chloride deposits and spatially associated hydrated mineral deposits23. The chloride deposits are light toned in true color and appear blue in the chloride browse products. The CRISM images are ∼ 10 km wide at their narrowest. (c) HiRISE images of strongly blue-colored regions exhibit a light-toned fractured and blocky appearance. The colored boxes correspond to the location of the HiRISE subframes within the CRISM images. via PubMed

The proposed chloride salt-bearing deposits on Mars have an enigmatic composition due to the absence of distinct spectral absorptions for the unique mineral at all wavelengths investigated.

We report on analyses of remote visible-wavelength spectroscopic observations that exhibit properties indicative of the mineral halite (NaCl) when irradiated. Visible spectra of halite are generally featureless, but when irradiated by high-energy particles they develop readily-identifiable spectral alterations in the form of color centers.

Consistent spectral characteristics observed in the reflectance data of the chloride salt-bearing deposits support the presence of radiation-formed color centers of halite on the surface of Mars.

We observe a seasonal cycle of color center formation with higher irradiated halite values during winter months, with the colder temperatures interpreted as increasing the formation efficiency and stability.

Irradiated halite identified on the surface of Mars suggests that the visible surface is being irradiated to the degree that defects are forming in alkali halide crystal structures.

Spectral evidence for irradiated halite on Mars Sci Rep. 2024; 14: 5503. Published online 2024 Mar 6. doi: 10.1038/s41598-024-55979-6 via PubMed (open access)

Astrobiology, Astrochemistry, Astrogeology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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