A campaign to collect geological samples in the Makgadikgadi salt marsh area in Botswana took place 9-17 September. While today this region of Africa is a vast expanse of salty clay, in the past it was home to a large lake, making it a ‘Martian analogue’, i.e. a place on Earth with geological or environmental characteristics similar to those of Mars.

The site has large areas where water/rock interaction can be studied and has similar geomorphological aspects to the Rosalind Franklin rover landing site (Oxia Planum). Thus, it represents a true laboratory in which to collect samples, perfect for study by the Ma_MISS spectrometer.

During the campaign, which lasted just over a week and involved two members of the Institute of Space Astrophysics and Planetology – INAF, supported by two members of BIUST (Botswana International University of Science & Technology), 35 samples of lake sediments were collected, in particular salt crusts, clays, sands and samples with traces of biological signatures.

The samples will then be measured in the laboratory with the DAVIS instrument, which can be considered comparable to the one that will measure the Martian subsurface. Some of the collected samples will be drilled to obtain a hole with the same characteristics (diameter and surface roughness of the hole wall) as those that the Rosalind Franklin rover will drill on Mars. Finally, a series of spectral scans will be performed to characterise the chemical and physical properties of the samples.

In addition to preparing for the activity and interpreting the scientific data that the Ma_MISS instrument will provide during the active phase of its Mars mission, field campaigns such as the one just conducted in Botswana enable us to improve our ability to search for any traces of past or present life and to understand the way in which life itself may be preserved, so that we can also prioritise astrobiological targets on the ground.