19/04/2018

When life is “blowing in the wind”


The Group of Atmospheric Science (GAS), through the participation of professor María Paz Zorzano and Ricardo Fonseca in a collaboration with Armando Azua-Bustos, currently working at the Spanish Centre of Astrobiology (CAB), has just started a campaign aimed to characterize the aerial transport of microbial organisms in the Atacama Desert, Chile. As a renowned Mars analogue site on Earth, Atacama offers the conditions to study the possible transport of biomass by wind and on aerosols, and the implications it can entail for the exploration of Mars by the upcoming missions.

Image of one of the sampling sites during the first day of the campaign.
Credits: Group of Atmospheric Science (GAS)/LTU

An “affordable” way to do research associated to the Mars environment is… to investigate at Martian analogues on our own planet. So, Mars on Earth? Certain places of our planet reproduce faithfully some environmental conditions on Mars, and the Atacama Desert, in Chile, is one of the best examples of this. The campaign, called “Atacama-2018 LAREX” (Low-cost AeRobiology EXpedition), is being carried out through a collaboration with Armando Azua-Bustos, currently working at the Spanish Centre of Astrobiology (CAB) and is part of the HABIT project of the ExoMars 2020 mission. HABIT has two containers that will collect atmospheric aerosols on Mars, and the LAREX campaign will mimic this process on a Martian-like environment. However, for the case of Earth, the aerosols will be collected on Petri dishes, and analysed not only in context of the atmospheric aerosol transport, but also to find life in an extreme arid region.

The idea is to investigate “on site” the possible transport of biomass by wind and on aerosols in one of the most arid environments on Earth, as an analogue for biomass transportation on Mars (i.e. when there are no liquid flows as in rain, snow, rivers, or seas to mix life all around), regarding the implications it can entail for the exploration of the planet by the upcoming missions. It is a “low cost” scientific campaign because it is based on remote cooperation between multiple institutions of different countries, being only necessary to send the required materials and sensors to a local contact, Carlos González Silva, from the University of Tarapacá, who is in charge of the operations in Atacama.

Basically, the campaign consists on collecting air samples and environmental data acquisition every two months, from now to the end of the summer 2018, at three different points separated between 20 km and 70 km from each other in the most remote and arid area of the desert.

Simulations of the wind profile on Atacama
during the season of the campaign.
Credits: Group of Atmospheric Science (GAS)/LTU

The biological samples will be analysed at CAB in Spain to catalogue the present organisms, whereas the environmental data will be processed at LTU through their comparison with high-resolution simulations from Weather Research and Forecasting (WRF) model. Finally, the dust settling and lifting processes will be compared with those observed with the REMS instrument operating now on the NASA Curiosity rover at Gale crater on Mars.

Ricardo Fonseca, another member of GAS, is analysing atmospheric circulation over the study area, with the aim of defining the wind orientation and of determining which valleys/structures are communicated by air and which ones are more isolated, giving a proper context to the observed biological transport patterns.

The results from this campaign will be relevant for planetary protection studies in which GAS is involved, as well as for the interpretation of REMS and HABIT dust related observations.



Watch the video of Armando Azua-Bustos TED talk on Atacama