How does life begin and evolve? Does life exist elsewhere in the Universe?
What is life's future on Earth and beyond? These most profound questions are
the focus of Astrobiology, the study of the origin, evolution, distribution and
destiny of life in the Universe. Recent advances in biology and space
exploration and technology make it possible for us to find answers.
Astrobiology is multidisciplinary and closely linked to diverse research topics
in astrophysics, molecular biology, biochemistry, prebiotic chemistry, ecology
of extremophiles, microbiology, physiology, planetary sciences, geology,
palaeontology, space exploration and technology, law, and philosophy.
Within the department of astrophysics, geophysics and oceanography, two
areas of research in astrobiology are developed and include the search for
signs of life in the solar system and beyond.
The detection of extrasolar life involves the detection of earth-like
exoplanets and the analysis of their atmospheric composition to detect
potential spectroscopic biosignatures such as ozone or water. The HARIGS group
(high angular resolution imaging from ground and space) is mainly oriented
towards exoplanet detection and characterization, using new techniques such as
interferometry and coronography (http://vela.astro.ulg.ac.be/themes/telins/harigs/welcome.html).
Astrobiologists also develop knowledge and technologies for the detection of
potential past or recent life in our solar system. The search for past or
present life beyond Earth requires a solid understanding of life's origin and
evolution on the only planet on which life is known to exist-the Earth. Hence,
the search for evidence of life and environments on the early Earth, where life
originated, evolved and later developed complexity are critical components in
developing mission plans for Astro/Exobiology space missions. Instruments
deployed on Mars or on returned samples to look for traces of past life
(programme AURORA link:
should be tested on fine-grained terrestrial sedimentary rocks where
biosignatures are known to be preserved. Emmanuelle Javaux' research is
relevant to the search for life on other planets in two ways. Firstly, her
ultimate goal is to understand the mechanisms and environmental context of
biospheric evolution on the early Earth by identifying the fossils (be they
morphological, ultrastructural, or chemical) of early prokaryotes and
eukaryotes, determining their biological affinities, and examining their
patterns of evolution through intervals of environmental change. This approach,
in which sedimentary geology, optical and electronic microscopy, and
microchemistry are used in combination, is applicable to Martian sediments.
Indeed, terrestrial discoveries provide a comparative database for evaluating
extraterrestrial materials and for characterizing biosignatures (features whose
presence or abundance require a biological origin).
This ongoing research (in collaboration with many international scientists
including members of the CNRS, Harvard University and the Australian Center for
Astrobiology) includes the determination and characterization of resistant
biopolymers in a range of living prokaryotes, protists and fungi by actualistic
taphonomy, combined microscopy and microchemistry, the determination of the
modifications of chemical composition due to thermal alteration, and the
comparison with combined microscopy (light microscopy, SEM, TEM) and
microchemical analyses (carbon structure, biopolymer composition, biomarker
molecular components, and both elemental and carbon isotopic composition) of
Proterozoic and Archean microfossils. This will permit us to characterize
biosignatures needed for paleobiology and astrobiology. Such a
multidisciplinary approach offers new possibilities to investigate the record
of early life on Earth and beyond.