Proof of life on Mars? Scientists say chemicals in a stream in Dorset show there are 12,000 Olympic-sized pools of organic matter on the red planet
- Experts studied a stream on the Jurassic coast to analyse chemicals on Mars
- They calculated how much organic matter could be Mars and where to look
- There may be 12,000 Olympic-sized pools of organic matter on the red planet
- This matter could represent traces of past life that inhabited the planet
The Dorset countryside has stood in for Mars as scientists hunt for life on the red planet.
By studying a stream on the Jurassic coast, experts have calculated how much organic matter we might find on Mars, and where to look.
When they applied their findings to the red planet, they concluded there could be nearly 12,000 Olympic-sized pools of organic matter on Mars.
The team found traces of fatty acids – key building blocks of biological cells – in an acidic stream in Dorset.
Because modern-day streams in Dorset are similar to Mars’ ancient waterways, the findings hint that life existed on the red planet billions of years ago.
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The Dorset countryside has stood in for Mars as scientists hunt for life on the red planet. By studying a stream (pictured) on the Jurassic coast, experts have calculated how much organic matter we might find on Mars, and where to look
Dorset is home to highly acidic sulphur streams that host bacteria which thrive in extreme conditions.
One such environment, in St Oswald’s Bay, near Weymouth, mimics the conditions on Mars billions of years ago.
Researchers at Imperial College London treated the landscape as a template for Mars and examined the organic matter preserved in rock deposits nearby.
The iron-rich mineral goethite transforms to hematite which is very common on Mars and gives the planet its red colour.
If the iron-rich minerals harbour traces of life on Earth, then scientists say they may hold clues to past microbial life on the Red Planet.
Study co-author Jonathan Tan said: ‘St Oswald’s Bay is a present-day microcosm of middle-aged Mars.
When they applied their findings to the red planet, they concluded there could be nearly 12,000 Olympic-sized pools of organic matter on Mars. This matter could represent traces of life that inhabited the planet billions of years ago (stock image)
‘As the acid streams dry up, like during Mars’ “drying period”, they leave goethite minerals behind which preserve fatty acids that act as biological signatures.’
Their study found that goethite in St Oswald’s Bay hosted many microbes as well as traces of their fossilised organic remains.
The researchers applied the results to a Martian environment.
Based on how much rock is from acid environments on Mars, and assuming the concentration of fatty acids found in Martian sediments matches that of Earth, there might be up to 28.6 million tonnes of fatty acids preserved within Martin rock.
This is equivalent to nearly 12,000 Olympic-size pools.
Previous missions to find traces of life have used heat to inspect rock for the presence of organic matter.
Scientists suspect the heat might have caused minerals to react with any organic matter, explaining why we haven’t yet found traces of life.
DO SCIENTISTS BELIEVE WE COULD EVER FIND LIFE ON MARS?
Over the years, scientists have found a number of promising signs that life may have been present on Mars, including evidence of water, chemical reactions, and expansive ice lakes beneath the surface.
Life on Mars is unlikely to have flourished on the surface, given the harsh conditions – including radiation, solar winds, and frigid temperatures.
As a result, many scientists believe organisms evolved to live beneath the surface of the Red Planet.
In November 2016, Dr Christian Schröder, an environmental science and planetary exploration lecturer at Stirling University, said: ‘For life to exist in the areas we investigated, it would need to find pockets far beneath the surface, located away from the dryness and radiation present on the ground.’
This is supported by evidence of water beneath the surface.
Researchers have identified mudstones and sedimentary bands on Mars, which only form when there is water present for thousands of years.
Vast oceans of ice have also been uncovered, lying just below the surface of the planet.
The presence of ice and water beneath the Red Planet greatly increases the chances that there was once at least microscopic life on Mars and that some form of the organism could be living there today.
‘Any place on Earth we find liquid water we find life,’ Jim Crocker, vice president of Lockheed Martin’s Space Systems said in August 2016.
‘It’s very exciting to understand the possibility that life could possibly have started on Mars before it lost its atmosphere, and perhaps even in the deeper surfaces, where water is still liquid because of the heat of the planet, perhaps there’s bacterial life.’
Having water just below the surface also means that human colonies could survive and even thrive on the planet and indicates that fuel for manned spaceflight could be manufactured there.
In 2017, Nasa’s Curiosity rover also found evidence of boron on the red planet’s surface.
This is another key ingredient for life, and scientists say the find is a huge boost in the hunt for life.
Boron was unearthed in the Gale Cater, which is 3.8 billion years old, younger than the likely formation of life on Earth.
That means the conditions from which life could have potentially grown may have existed on ancient Mars, long before organisms began to develop on Earth.
A controversial 2001 study into a 4.5 billion-year-old meteorite, dubbed ALH84001, which was found in Antarctica’s Allan Hills ice field in 1984, claimed it had definitive prove of life on Mars.
Meteorite ALH84001 was blasted off the surface of Mars by a comet or asteroid 15 million years ago, and Nasa researchers said it contains proof the Red Planet was once teeming with bugs which lived at the bottom of shallow pools and lakes.
They also suggested there would have been plants or organisms capable of photosynthesis and complex ecosystems on Mars.
However British experts said at the time that the evidence, though exciting, had to be treated with caution and could not be taken as conclusive, since many non-biological chemical processes could also explain what was found.
But heating goethite or hematite does not destroy any organic matter that’s there, meaning these minerals could be ideal targets in the search for life.
Co-author Professor Mark Sephton, of Imperial College, said: ‘Mars harboured water billions of years ago, meaning some form of life might have thrived there.
‘If life existed before the water dried up, it would probably have left remains that are preserved to this day in Martian rock.
‘However, we have yet to find convincing traces of organic matter that would indicate previous life on the red planet.
‘Now we should let Dorset’s landscape guide our life detection efforts on the Red Planet.’
The researchers say that if traces of life are found on Mars, it will probably be in the form bacteria that can thrive in extreme environments – such as the acid streams on Earth.
They hope to programme the next life-searching mission to Mars, Mars 2020, to search for dried up streams and inspect the sediment for traces of fatty acids.
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