2016

Spring mounds on Earth: terrestrial analogues to Mars environments (Dr. F. Franchi)

Category: Use of Extreme Environments to advance the exploration and settlement of space

Institution: Botswana International University of Science and Technology.

The aim of this project was a detailed astrobiological characterization of terrestrial spring carbonate mounds. Samples for this project were collected in the Makgadikgadi Pan during an expedition lead by Botswana International University of Science and Technology (BIUST). Carbonate precipitation in mounds is believed to result from a continuum of non-biological and biological processes. Combinations of these factors produces a specific associations of carbonate microfabrics that, combined with information about geometry and internal architecture of the carbonate build-ups, can be indicative of specific depositional settings. Hence from the microfabrics in the Makgadikgadi pan mounds it is possible to shed light onto past depositional setting where microbial communities thrived.

Specifically this type of investigation may shed light onto the capacity of microbial communities to survive profound crisis and to recover after major extinctions. And for astrobiology: are the chemophysical conditions of the Australian mounds comparable with what we know of early Mars?

New findings will shed light on the evolution of early life on both planets. The project was based on promising preliminary work, which recognized the great astrobiological significance of terrestrial mounds in arid environments as analogues of Martian equatorial region morphologies.

In summary, this research evaluated the astrobiological potential of the Makgadikgadi springs and shed new light on the bio-mediated processes active at spring sites and the related micro-structures. This work provided a multiscale model spanning from the km-sized mound fields to the μm-sized microbial morphology. The final Outcome will be the close correlation between spring mound processes of bio-mineralization and interactions with Martian-like agents of erosion and post-depositional modifications. These will unequivocally demonstrate the role of extremophiles on both Earth and Mars landscape evolution.