What the Missing Antarctic Microbes Mean for Life on Other Planets

Microbes can be invisible to the naked eye, yet they form an integral part of every ecosystem on Earth. From grasslands and deserts to forests and marine habitats, microbes are found all over the planet. Typically, a spoonful of soil can contain billions of microbes.

Scientists, led by ecologist Noah Fierer collected 204 soil samples near Antarctica’s Shackleton Glacier. Surprisingly, the samples seemed incapable of hosting life — coming back with no microbes at all.

If confirmed, this will be the first time scientists have found soil that doesn’t support any microbial life. What’s more, experts say these conditions bear resemblance to the surface of Mars — giving researchers a look inside the possibility of life (or lack thereof) on the Red Planet. These findings suggest that an extremely cold and arid climate like that of the sample site may be incapable of hosting life.

While proving a negative in science is notoriously difficult, this leads to the question — If microbes can’t even survive in this Antarctic climate, what does that mean for life on other planets?

After years of experimenting on the Antarctic soil, Fierer’s team felt confident enough to declare they could not detect life in their samples. While other microbiology experts claim this could be a false-negative, even if there are just a few undetected microbes in the soil —there is still evidence that cold and dry climates pose a significant challenge to life.

As scientists continue to search for the possibility of aliens, “they will inevitably be forced to walk the line between evidence of absence and absence of evidence.”