A NASA rover equipped with a drill has collected micro organisms from three feet underground in Chile’s Atacama desert, a study claims.
It is hoped that the experiment will give scientists a clearer picture of what kind of bacteria they might expect to get from the arid soil on Mars.
They use the Atacama desert as a testing ground because it is the most ‘Mars-like’ region on Earth and will accurately replicate the harsh, irradiated environment.
The robotic rover collected micro-organisms from the subsurface soil ahead of NASA and European Space Agency missions to the Red Planet in 2020.
The microbes they found had adapted to high salt levels, similar to what may be expected in the Martian subsurface.
Scroll down for video
A NASA rover equipped with a drill has collected micro organisms from three feet under the ground in Chile’s Atacama desert. It is hoped that the experiment will give scientists a clearer picture of what kind of bacteria they might expect to get from the arid soil on Mars
The robotic rover collected micro-organisms from the subsurface soil ahead of NASA and European Space Agency missions to the Red Planet in 2020. The microbes they found had adapted to high salt levels. Here, the drill attached to the rover
Because of its high UV radiation exposure and very salty soil, the desert is the closest match and therefore the best place for simulating missions to this planet.
Study leader Professor Stephen Pointing, of Yale-NUS College, Singapore, said: ‘We have shown that a robotic rover can recover subsurface soil in the most Mars-like desert on Earth.
‘This is important because most scientists agree that any life on Mars would have to occur below the surface to escape the harsh surface conditions where high radiation, low temperature and lack of water make life unlikely.
‘We found microbes adapted to high salt levels, similar to what may be expected in the Martian subsurface.
These microbes are very different from those previously known to occur on the surface of deserts.
The autonomous solar-powered rover travelled 31 miles (50 km) over two types of terrain similar the surface of Mars.
One was stony desert pavement, and the other was sandy and typical of the desert environment.
The samples recovered by the autonomous rover contained unusual and highly specialised microbes that were distributed in patches.
The scientists use Atacama desert because it is the most ‘Mars-like’ driest region on Earth and will replicate the harsh, irradiated environment. Experts say that future research includes drilling deeper to understand just how far down recoverable microbes occur
Researchers then linked their dispersal to limited water availability, scarce nutrients and chemistry of the soil.
The drill used in the study had a depth of 31.5 inches (80cm) and its samples were compared to those recovered by hand.
In the coming years rovers will be deployed to Mars to drill below the ground to find evidence of past or present life.
Mars missions hope to drill to approximately 2m and so having an Earth-based comparison will help identify potential problems and the interpretation of results.
‘Ecological studies that help us predict the habitable areas for microbial communities in Earth’s most extreme environments will also be critical to finding life on other planets,’ said Professor Pointing.
DNA sequencing found the results of each methods were similar and that the trial was a success.
Mars missions hope to drill to approximately 2m and so having an Earth-based comparison will help identify potential problems and the interpretation of results. Here, Images of the surface of Mars taken by the European Space Agency
Professor Pointing said future research includes drilling deeper to understand just how far down recoverable microbes occur.
The tests also revealed that microbial life was very patchy and related to the limited water availability, scarce nutrients and geochemistry of the soil.
Study co-author Dr Nathalie Cabrol, of The SETI Institute, said: ‘These results confirm a basic ecological rule that microbial life is patchy in Earth’s most extreme habitats, which hints that past or present life on other planets may also exhibit patchiness.’
She added: ‘While this will make detection more challenging, our findings provide possible signposts to guide the exploration for life on Mars, demonstrating that it is possible to detect life with smart robotic search and sampling strategies.’
The findings of the study were published in the journal Frontiers in Microbiology.
WHAT EVIDENCE DO SCIENTISTS HAVE FOR LIFE ON MARS?
The search for life on other planets has captivated mankind for decades.
But the reality could be a little less like the Hollywood blockbusters, scientists have revealed.
They say if there was life on the red planet, it probably will present itself as fossilized bacteria – and have proposed a new way to look for it.
Here are the most promising signs of life so far –
When looking for life on Mars, experts agree that water is key.
Although the planet is now rocky and barren with water locked up in polar ice caps there could have been water in the past.
In 2000, scientists first spotted evidence for the existence of water on Mars.
The Nasa Mars Global Surveyor found gullies that could have been created by flowing water.
The debate is ongoing as to whether these recurring slope lineae (RSL) could have been formed from water flow.
Earth has been hit by 34 meteorites from Mars, three of which are believed to have the potential to carry evidence of past life on the planet, writes Space.com.
In 1996, experts found a meteorite in Antarctica known as ALH 84001 that contained fossilised bacteria-like formations.
However, in 2012, experts concluded that this organic material had been formed by volcanic activity without the involvement of life.
Signs of Life
The first close-ups of the planet were taken by the 1964 Mariner 4 mission.
These initial images showed that Mars has landforms that could have been formed when the climate was much wetter and therefore home to life.
In 1975, the first Viking orbiter was launched and although inconclusive it paved the way for other landers.
Many rovers, orbiters and landers have now revealed evidence of water beneath the crust and even occasional precipitation.
Earlier this year, Nasa’s Curiosity rover found potential building blocks of life in an ancient Martian lakebed.
The organic molecules preserved in 3.5 billion-year-old bedrock in Gale Crater — believed to have once contained a shallow lake the size of Florida’s Lake Okeechobee — suggest conditions back then may have been conducive to life.
Future missions to Mars plan on bringing samples back to Earth to test them more thoroughly.
In 2018, Curiosity also confirmed sharp seasonal increases of methane in the Martian atmosphere.
Experts said the methane observations provide ‘one of the most compelling’ cases for present-day life.
Curiosity’s methane measurements occurred over four-and-a-half Earth years, covering parts of three Martian years.
Seasonal peaks were detected in late summer in the northern hemisphere and late winter in the southern hemisphere.
The magnitude of these seasonal peaks – by a factor of three – was far more than scientists expected.