Search for the most ancient traces of Life on Earth

**Alexandre Simionovici, professor at ISTerre

"Initially a CNRS scientist in Atomic Physics (few electron multicharged ions), then head of a beamline at the ESRF synchrotron (7 years: building/operating the ID22 µ-analysis beamline), I joined the ISTerre/UGA as a professor, in 2006. There I have developed a quantification method of trace/ultratrace elemental/molecular signatures of unique samples: cometary/interstellar grains of the NASA Stardust mission and NASA MSR (Mars Sample Return), in a non-destructive/non-invasive way, preserving their structure and morphology.

This X-ray hyperspectral nano-imaging method couples fluorescence and speciation/tomography/diffraction, aiming to detect in quarantine, in conditions of planetary protection, the presence of current/fossil life, on the Mars samples returned to Earth. Other current applications include the origin of life on Earth at the Archean, (- 3.4 Ga) the structure of achondrite meteorites and the study of heavy metal environmental pollution.

The subject of this podcast is “Search for the most ancient traces of Life on Earth”, and it was recorded in collaboration with Laurence Lemelle of the LGL-TPE laboratory, at ENS Lyon, as part of our IDEX – CDP COOL (Crossdisciplinary Origin Of Life) project of UGA. Our target is one of the iconic sites of the oldest fossils, in the rocks of the Barberton Greenstone Belt, in South Africa, which were dated at 3.3-3.4 Ga.