Looking for life on Mars won’t be easy. If it exists, it’ll be microbial and almost certainly buried slightly beneath the surface. It’ll revolutionize human civilization should we find that our lonely planet isn’t the only one that contains life, but it’s not as simple as heading to our neighbor and poking around in the dust.
Knowing where to search for it is half the battle – and a new study has come up with a rather ingenious way of finding traces of life. Using this “life detection platform”, future exploratory missions to the Red Planet may be able to follow a trail of biosignature breadcrumbs right to their source.
The research, headed by McGill University, led an interdisciplinary team to the Canadian Arctic. Specifically, they dug around in the permafrost there, chilly soil that’s frozen for two consecutive years.
At present, permafrost tends to make headlines for how quickly anthropogenic climate change is causing it to melt, as well as the caches of biogenic and geologic methane stored within it. This team were far more interested in the life contained within, and for good reason: The conditions here are somewhat similar to those on Mars.
Despite the fact that there’s still plenty of water on Mars, it’s generally an arid place. Its stripped-down atmosphere means that the surface is constantly bombarded by radiation; in addition, the atmospheric pressure there is incredibly low and the surface temperatures plunge from -73°C (-100°F) around the equator to -125°C (-195°F) at the poles.
The Canadian Arctic isn’t quite like that, but it’s similar enough to allow teams like this one to use the presence of microbial life there as an analogue to parts of Mars. If the Arctic contains extremophiles – organisms that thrive in particularly troublesome environments – then why couldn’t Mars?
The team wanted to know how many different ways they could detect life squirming around within the permafrost. To wit, they designed a package of instruments, ones that could not just dig up microbes, but run tests on them, all without requiring transportation back to a laboratory.
Writing in the journal Frontiers in Microbiology, they explain that just picking up on DNA fragments doesn’t tell you that much. Life may once have been there, but it might not be anymore.
Their portable low-cost lab, however, can not only detect and sequence DNA from both living and deceased critters, but it can also isolate individual extremophilic microorganisms and assess their activity.
Their pioneering trial experiments with Canadian extremophiles proved that both the signatures of life and life itself can be accurately detected and analyzed.
“The life detection platform we are trying to develop is in its very early stages, and at this point, we have really only shown proof of concept,” lead author Dr Jackie Goordial, a postdoctoral researcher now based at the Bigelow Laboratory for Ocean Sciences, told IFLScience. “There is still a lot of work to be done.”
So although it's not ready to head into space just yet, this could represent the precursor to the equipment that reveals we aren’t alone after all.
Goordial tells us that there are several spots on Mars that she would point her new platform at, including “the reoccurring slope linnaea that may or may not be brine water flowing on Mars, the subsurface ice-cemented ground in the polar regions, or locations that may have been the site of past hydrothermal activity.
“These are all places that we know on Earth host extremophilic life.”
This study isn’t the first of its kind; plenty of others have recently headed to some of the coldest, harshest environments on Earth in order to conduct dry runs in preparation for the future. Others have taken microbial samples from the cryosphere and subjected them to Martian atmospheric conditions in the laboratory, and one recent paper suggests that a microbiome could exist on Mars and survive for 20 million years.
With that in mind, we don’t know at present if life on Mars is definitely there, but research is suggesting that it’s a distinct possibility. This new study, then, provides us with a novel way of searching for it when the time comes to finally head a little bit further out into that starry ocean above our heads – to Mars, Europa, Enceladus, and beyond.