24-104 Mineralogy and Photometry of Mars Satellites

  • Meudon
  • Cnes Centre National Detudes Tiales

Doctorat, 36 mois

  • Temps plein
  • Aucune expérience exigée
  • Maitrise, IEP, IUP, Bac+4
  • Planets & small bodies of solar system

Mission : The JAXA Mars Moons Exploration (MMX) mission will be launched in September 2024 to the Martian system to return samples from the surface of Phobos, make detailed observations of Phobos and Deimos, and monitor the climate of Mars. The main goals of the mission is to return samples of Phobos, and, throughout both the in situ detailed investigation of Mars satellites and the laboratory studies of Phobos samples on Earth, to finally clarify the origin of the Mars Martian moons. In fact, their origin is debated, and two theories are proposed: a) Phobos and Deimos are asteroids captured by Mars, a hypothesis reinforced by the spectral similarity between them and primitive D-type asteroids; b) The satellites would have formed in situ, from a debris disk produced by the collision of a large object with Mars.

1) Creation of a software for automatic detection of absorption bands and compounds at the origin of a given absorption band from a spectrum. A spectral catalogue listing the bands (center, width, typical depth) characteristic of the various minerals-compounds (silicates, hydrated minerals, carbonates, organic matter, igneous matter, etc.) likely to be detected on the surface of Phobos, Deimos and Mars exists at LESIA and should be expanded. While waiting for MMX data, this software will be tested and validated on data provided by the LESIA planetology team on small bodies.

3) Support the in-flight calibrations of the MIRS instrument starting from 2025, and the data analysis and interpretation acquired from MIRS in 2025-2027 from various altitudes. The PhD student will analyze the MIRS spectra and constrain the Martian satellites composition. Particular attention would be given at the identification of bands associated with hydrated minerals and organics, that, if detected, will point toward the captured asteroid origin for the asteroid. Spectral maps will be generated and this work will be very important also in support of the landing site selection. Space weathering process (i.e., spectral variations of the surface produced by cosmic rays, solar wind, and micrometeorite bombardment) will also be investigated comparing the composition of different geomorphological features including relatively young craters versus older surfaces.

4) Carry out laboratory measurements on planetary analogs, minerals and meteorites helping in the interpretation of Phobos and Deimos MIRS spectra, and in constraining their surface composition and physical properties. Various mixtures will be tested, varying abundances, grain size and geometric observations conditions. We have started developing a laboratory facility at LESIA equipped with industrial spectrometers, sources, and a goniometer. In the near future, we plan to use MIRS Engineering Model (EM1) as spectrometer. The MIRS EM1 is a perfectly functioning instrument with performances close to the flight model, and it will be available for measurements starting from spring 2024.

During the first year of the PhD, tasks 1,2 and partially 4 will be developed, while the 2nd and 3rd years will be consecrated to MIRS data analysis and interpretation, and to the laboratory measurements. If any delay in the mission launch will happen, the PhD work will be mainly focused on laboratory experiments with MIRS EM1, and to past missions data interpretation (MEX-HRSC and ExoMars-CASSIS) in support of the MMX observations.

=================

Profil : master in planetary sciences, astrophysics, or space sciences; skills in data analysis, modeling, programming

Laboratoire : LESIA

Message from PhD :