Publication
Names
  • Lucia Mandon
  • Beck Pierre
  • Cathy Quantin-Nataf
  • Erwin Dehouck
  • Antoine Pommerol
  • Zurine Yoldi
  • Romain Cerubini
  • Lu Pan
  • Melissa Martinot
  • Violaine Sautter
Title
Martian meteorites reflectance and implications for rover missions
Abstract
In the next decade, two rovers will characterize in situ the mineralogy of rocks on Mars, using for the first time near-infrared reflectance spectrometers: SuperCam onboard the Mars 2020 rover and MicrOmega onboard the ExoMars rover, although this technique is predominantly used in orbit for mineralogical investigations. Until successful completion of sample-return missions from Mars, Martian meteorites are the only samples of the red planet available for study in terrestrial laboratories and comparison with in situ data. However, the current spectral database available for these samples does not represent their diversity and consists primarily of spectra acquired on finely crushed samples, albeit grain size is known to greatly affect spectral features. Here, we measured the reflected light of a broad Martian meteorite suite as a means to catalogue and characterize their spectra between 0.4 and 3 μm. These measurements are achieved using a point spectrometer acquiring data comparable to SuperCam, and an imaging spectrometer producing hyperspectral cubes similarly to MicrOmega. Our results indicate that point spectrometry is sufficient to discriminate the different Martian meteorites families, to identify their primary petrology based on band parameters, and to detect their low content in alteration minerals. However, significant spectral mixing occurs in the point measurements, even at spot sizes down to a few millimeters, and imaging spectroscopy is needed to correctly identify the various mineral phases in the meteorites. Additional bidirectional spectral measurements on a consolidated and powdered shergottite confirm their non-Lambertian behavior, with backward and suspected forward scattering peaks. With changing observation geometry, the main absorption strengths show variations up to ~10–15%. The variation of reflectance levels is reduced for the consolidated sample compared to the powder. All the spectra presented are provided in the supplementary data for further comparison with in situ and orbital measurements.
Keywords
spectroscopy, spectro-gonio radiometer, photometry, data analysis, visible, near-IR, meteorites, SNC, Shergottite, Nakhlite, Chassignite
Content
sample, material-matter, spectral data, planetary sciences
Year
2021
Journal
Icarus
Volume
366
Pages
114517
Pages number
26
Document type
article
Publication state
published