Afternoons in the Atacama are particularly windy and dusty. Not quite to the same level as Mars, which has experienced planet wide dust storms in the past, but windy enough to carry particles of dust vast distances. The bacteria and fungi found in the core of the Atacama then, may have originated elsewhere, particularly closer to the coast. Based on the species of bacteria, the researchers suggest, the marine environment of the coastal range may be a starting point.
Intriguingly, the team also found two bacterial species growing in their broth that have been previously reported as airborne bacteria. The species were originally spotted in China and India -- which means they may have come from even further away. The team writes that future work will investigate their origin.
How does this all relate to life on Mars? Well, as a great analog, the Atacama desert provides a good testing ground for these kinds of theories. It's impressive that miniature beasts like bacteria and fungi can move distances that would make humans wince, and it's all thanks to the dusty winds. Based on what the researchers saw on Earth, they say there's a possibility that Martian dust could have carried microbes across the red planet in the past.
Mars doesn't seem particularly kind to life. It's desolate, arid and lacks a protective atmosphere. However, in the past, there may have been pockets where life could exist. Azua-Bustos and his colleagues suggest the transport system they propose could have allowed microbial life to survive and even to evolve, by dispersing from habitable location to habitable location.
Of course, the speculative Mars microbe transport system is, for the time being, impossible to put to the test on the red planet. For now, we just have tantalizing potential glimpses of life. However, two new rovers will settle in on the Martian surface in the coming years. The European Space Agency's Rosalind Franklin will search for signs of life on Mars, as will NASA's as-yet unnamed Mars 2020 rover, which is scheduled to land in Jezero Crater in 2021.