Life on Mars clues following discovery of salt water beneath Antarctica

29 Apr 2015

Researchers have found evidence of a large body of very salty water hundreds of metres underneath Antarctica’s valleys, which lends further clues as to the existence of something similar on Mars.

Antarctica’s McMurdo Dry Valleys are some of the coldest, driest, most inhospitable locations on Earth.

They work as a comparison to what the environment is like on Mars, although not exactly, obviously.

For a long time now scientists thought the ground there was a combination of ice and rock, however, new research has thrown up data that suggests zones of liquid water are hidden far beneath the ice.

These deep, heavily salted “subpermafrost” pools have the potential to harbour numerous forms of life in a quite unique ecosystem, one that may well be mirrored on Mars. That’s because the briny, salty water freezes at a far lower temperature, due to its make-up.

Ross Virginia, co-author of the study that appears in Nature Communications, spoke to The Verge about his findings, noting that before this research nobody truly knew what type of life could exist beneath the cold, frozen rock and ice-formed tundra.

This study opens up “possibilities for better understanding the combinations of factors that might be found on other planets and bodies outside of the Earth”, he said.

For the study, Virginia and his team flew a helicopter over Taylor Valley – one of the three that make up McMurdo Dry Valleys – with a bizarre device known as SkyTem.

SkyTem basically worked as an electromagnetic sensor, or aerial, that could penetrate through the surface to gather readings.

This followed work from the 1970s that originally threw up interesting findings of what lay beneath the surface, with SkyTem’s sensor ideal for establishing the different bodies of rock, ice and really briny liquid.

“Regional-scale zones of low subsurface resistivity were detected that are inconsistent with the high resistivity of glacier ice or dry permafrost in this region,” reads the report, surmising that this third finding is an indication of liquid, with “sufficiently high solute content”.

The results suggest a network of pools or lakes, far beneath the surface, meaning that lakes which we cannot see from above, or can see but seem isolated from others, may be linked by a major underground network of rivers and streams.

This ties in with other research conducted recently. In January, researchers discovered two sub-glacial lakes in Greenland draining away.

The theory there was that a network of rivers linked them together and, when the conditions were right and the ice above heated up enough, wide-scale draining ensued.

“On Mars, the subsurface is the place to look. It’s less harsh, and could be where life could have found relief,” says Jill Mikucki, a microbial ecologist at the University of Tennessee, Knoxville, and one of the researchers working on the Antarctica project.

Indeed Mars is a hot topic of late, with NASA’s Curiousity rover currently investigating the existence of liquid water beneath the surface – but there is still no evidence of life existing on the planet.

According to the findings, this newly discovered liquid water exists in a heavily saline state, at a temperature in the region of -70C because of the salt’s ability to expand the freezing point of water, also helped by the inclusion of calcium perchlorate in the mix.

The comparisons with Antarctica are, therefore, blatant. So, is there life on Mars?

McMurdo Valley via Saxphile on Flickr

Gordon Hunt was a journalist with Silicon Republic