MICROMEGA : A VIS/NIR HYPERSPECTRAL MICROSCOPE FOR IN SITU ANALYSIS IN SPACE

摘要

MicrOmega is an ultra miniaturized spectral microscope for in situ analysis of samples. It is composed of 2 microscopes: one with a spatial sampling of 5μm, working in 4 color in the visible range and one NIR hyperspectral microscope in the spectral range 0.9-4 urn with a spatial sampling of 20μm per pixel (described in this paper). MicrOmega/NIR illuminates and images samples a few mm in size and acquires the NIR spectrum of each resolved pixel in up to 600 contiguous spectral channels. The goal of this instrument is to analyse in situ the composition of collected samples at almost their grain size scale, in a non destructive way. It should be among the first set of instruments who will analyse the sample and enable other complementary analyses to be performed on it. With the spectral range and resolution chosen, a wide variety of constituents can be identified: minerals, such as pyroxene and olivine, ferric oxides, hydrated phyllosilicates, sulfates and carbonates; ices and organics. The composition of the various phases within a given sample is a critical record of its formation and evolution. Coupled to the mapping information, it provides unique clues to describe the history of the parent body. In particular, the capability to identify hydrated grains and to characterize their adjacent phases has a huge potential in the search for potential bio-relics. We will present the major instrumental principles and specifications of MicrOmega/NIR, and its expected performances in particular for the ESA/ExoMars Mission.