People: Astrobiology Graduate Students

Jelte Harnmeijer
Earth & Space Sciences

Astrobiology is not only about the existence of life outside our own planet, but also about the study of how, when and why life started on Earth. If we are to have any chance of deducing the presence of extraterrestrial and/or extrasolar life, we should first be able to do so unambiguously on our own planet.

My Ph.D. research focuses on biogeochemical indicators - or their proxies - in Archaean terrains. The fact that virtually all Archaean rocks have been metamorphosed to some degree greatly complicates studies of ancient life. Indeed, virtually all our knowledge of life in the early Archaean is derived from a rather limited set of low-grade rocks in South Africa and Australia. The identification of geochemical biomarkers in higher-grade Archaean rocks holds vast potential for providing a greater understanding of our primordial biosphere, by expanding the range of rocks accessible to geobiological investigation. Additionally, and relevant to the exciting field of astrobiology , there is no reason why these geochemical 'meta-biomarkers' could not be applied to other planetary surfaces or even meteorites.

My work has two major objectives:
(i) The identification of biomarkers resistant to metamorphism and deformation, and a qualitative and quantitative understanding of the behavior of these meta-biomarkers under conditions of increasing pressure and temperature;
(ii) The application of these meta-biomarkers, particularly in ancient rocks bearing controversial evidence for the inception of life on Earth. Other candidates that may be scrutinized for the presence of such meta-biomarkers include Martian, lunar, and other meteorites.