content long 20-February-2018 14:59:48

The ExoMars Rover Instrument Suite

The MicrOmega Infrared Spectrometer

MicrOmega instrument prototype.
Credit: ESA - MicrOmega Team, Institut d'Astrophysique Spatiale

MicrOmega is a micro-imaging system designed to identify, at grain scale, the mineralogical and the molecular composition of the Martian samples collected by the ExoMars drill.

MicrOmega is included in the suite of analytical instruments that, along with MOMA (Mars Organics Molecule Analyser) and RLS (Raman Laser Spectrometer), will characterise the collected samples, and specifically the organic substances they may contain.

In particular, MicrOmega will analyse the samples with a view to unravelling their geological origin and composition by examining the minerals that they contain. Some minerals can act as monitors of the physical and chemical conditions under which the materials are formed. These data will be vital to characterise the past and present geological processes, climate and environment of Mars and specifically, to help identify evidence of carbon or the past presence of water. They can, therefore, be used to assess whether these samples might have acted as a suitable habitat for life, and whether they have preserved bio-relics.

In addition, MicrOmega can be used to locate grains of particular interest (for example, grains that may have been processed by liquid water) in a totally non-destructive manner, so as to assign them as targets for Raman and MOMA LD-MS observations.

MicrOmega consists of a visible light microscope and a near infrared imaging spectrometer. The instrument acquires monochromatic images with a high resolution of 20 µm × 20 µm per pixel at a few wavelengths between 0.5 µm and 0.9 µm and with a continuous and high spectral sampling from 0.9 µm to 3.5 µm. Therefore, for each pixel MicrOmega acquires the entire spectrum in a spectral domain, enabling it to identify the composition of the samples at their grain scale.


Instrument update

Image of sulphate sample at a pixel level acquired by the MicrOmega prototype.
Credit: ESA-MicrOmega Team, Institut d'Astrophysique Spatiale

A number of tests for MicrOmega have been carried out using a prototype of the instrument to monitor its capability and performance. The MicrOmega prototype includes

  1. a monochromator, based on an acousto-optical tunable filter (AOTF) illumination system;
  2. the infrared magnification optics;
  3. the infrared focal plane;
  4. the thermal control system; and
  5. the sample container.

The prototype has acquired spectral images of samples at a pixel level, analysing their composition and identifying the minerals that the samples contain.


MicrOmega participants
Principal Investigator
Jean-Pierre Bibring, Institut d'Astrophysique Spatiale, Orsay, France

Co-Principal Investigators
Frances Westall, Centre de Biophysique Moléculaire, Orléans, France
Nicolas Thomas, University of Bern, Switzerland
ESA contact
ExoMars instrument system engineer
Frederic Didot, Directorate of Science and Robotic Exploration, European Space Agency
More instrument details
The MicrOmega Investigation Onboard ExoMars
Bibring J.-P., Hamm V., Pilorget C., Vago J.L., and the MicrOmega Team, Astrobiology, July 2017, 17(6-7), 621-626

Last Update: 25 August 2017

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