Science News Desk – New research published today in Nature Communications shows that the rovers’ current instruments aren’t really up to the task of finding evidence of life. In astrobiology, we study the diversity of life on Earth in regions with environmental or physical features similar to those already described on Mars. We refer to these terrestrial environments as ‘Mars analog’ sites. The new research, led by Armando Azua-Bustos at the Center for Astrobiology in Madrid, used modern instruments currently used by NASA’s Curiosity and Perseverance rovers, as well as future instruments. Tested some of the new laboratory equipment employed for analysis.
Azua-Bustos and his colleagues found that the rovers’ tested instruments – the instruments used to analyze samples in the field – had limited ability to detect the signs of life we’d expect to discover on the Red Planet. can do. They were able to detect the mineral components of the samples, but were not always able to detect organic molecules. Our Mars analog sites are the dry valleys in Antarctica and the cold and ultra-arid deserts of the Windmill Islands. Life exists in both these places despite extreme pressure. Given the harsh conditions and the paucity of microbial life present, finding evidence of life is challenging.
First, we must define the existing (and being explored) biological and physical limits of life in analog ‘extreme’ environments. Then we need to develop tools to identify ‘bio signatures’ across a lifetime. These include organic molecules such as lipids, nucleic acids, and proteins. Finally, we determine how sensitive the instrument needs to be to detect those biosignatures on Earth and Mars. In my field of microbiology, ‘microbial dark matter’ is when the majority of microbes in a sample have not been isolated and/or characterized.
To identify them, we need to define next generation sequencing. Azua-Bustos’ team goes a step further and proposes a ‘dark microbiome’ that includes the possible remains of Earth’s extinct species. Azua-Bustos’ team found that modern laboratory techniques are not suitable for the Mars-like ultra-arid soils of the Atacama Desert. One can detect the deep microbiome in the samples. However, the current instruments of the rovers will not be able to detect it on Mars.
The search for life on other planets also depends on our understanding of what would be necessary for life to exist, the simplest of which are energy, carbon and liquid water. On Earth, most organisms use photosynthesis to obtain energy from sunlight. This process requires water, which is almost entirely unavailable in dry desert environments such as Antarctica and the Atacama Desert, and possibly Mars. We think a process we have dubbed ‘atmospheric chemosynthesis’ may fill this gap.