No canals on Mars but scientists discover strongest evidence yet planet was once habitable capable of supporting life

Red Planet had at least one large freshwater lake with right sort of chemical make-up to support kind of mineral-eating microbes seen on Earth

Science Editor

Scientists have discovered the strongest evidence to date that Mars was once a habitable planet capable of supporting primitive microbial life-forms at some time in the past.

An international team of researchers has found that about 3.6 billion years ago Mars had at least one large freshwater lake with the right sort of chemical make-up to support the kind of mineral-eating microbes seen on Earth.

Studies carried out by Nasa’s Curiosity Rover have for the first time revealed the existence of a type of sedimentary rock known as mudstone which is likely to have been created by a large body of standing water that had existed for at least many thousands of years.

Although the scientists emphasised that they have not yet found the smoking gun that proves the past existence of life on Mars, they are jubilant about finding what they believe is solid evidence that the planet was capable of supporting microbial life at some point in the past.

“I think it’s a step change in our understanding of Mars. It’s the strongest evidence yet that Mars could have been habitable for ancient microbial life,” said Professor Sanjeev Gupta of Imperial College London and a member of Nasa’s Mars Science Laboratory Curiosity mission.

“This is dramatic. We have effectively found what was once a standing body of water and although we don’t know how long it was there for, liquid must have been stable on the Martian surface for at least thousands or even millions of years,” Professor Gupta said.

Previous studies indicated that water had once flowed freely on Mars. Satellite images showed the kind of ground erosion that could have been caused by fast-moving water. This was further supported last year when the Curiosity rover found the smoothly-eroded pebbles of a dried-up river bed.

However, scientists believe that fast-flowing water is not conducive for the origin of life and so have been looking for lakes or ponds of permanent standing water that could have provided a more stable, habitable environment for the first Martian life-forms.

Mudstones usually form under calm conditions by the very gradual build up over long period of time of very fine grains of sediment which settle layer by layer on top of each other on the bed of a lake or sea.

The six-wheeled Curiosity rover found the mudstones at a place known as Yellowknife Bay near to its landing site within the Gale Crater, a 150 kilometre-wide impact basin with a mountain at its centre. Nasa sent Curiosity on a detour from its planned exploration of the mountain at the centre of the crater to explore a “thermal anomaly” at Yellowknife Bay.

Curiosity drilled into the rock and tested its composition with instruments designed to analyse the chemical makeup of solids when they are heated and vaporised. The studies, published in the journal Science, revealed the presence of the vital elements of life, namely carbon, hydrogen, oxygen, nitrogen and sulphur.

The study also found that the relatively neutral acidity of the lake would not have prevented life from forming, that the water was not too salty for life and that it could have existed as a standing body of water long enough for life to form.

It is possible that the mudstone beds extend for hundreds of metres deep under the Martian surface, which would represent tens of millions of years of geological time, the study found.

“We can envisage many combinations of terrestrial microbes that would be suited to form a Martian biosphere founded on chemolithoautotrophy [mineral-eating microbes] at Yellowknife Bay,” the study concluded.

Texture of the 'snake' as seen by MAHLI on Sol 149 Texture of the 'snake' as seen by MAHLI on Sol 149 (AFP/Getty) Professor Gupta said: “It is important to note that we have not found signs of ancient life on Mars. What we have found is that Gale Crater was able to sustain a lake on its surface at least once in its ancient past that may have been favourable for microbial life billions of years ago.

“This is a huge positive step for the exploration of Mars. It is exciting to think that billions of years ago, ancient microbial life may have existed in the lake’s calm waters, converting a rich array of elements into energy,” Professor Gupta said.

“The next phase of the mission, where we will be exploring more rocky outcrops on the craters surface, could hold the key to whether life did exist on the red planet,” he added.

Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
Life and Style
Suited and booted in the Lanvin show at the Paris menswear collections
fashionParis Fashion Week
Arts and Entertainment
Kara Tointon and Jeremy Piven star in Mr Selfridge
tvActress Kara Tointon on what to expect from Series 3
Voices
Winston Churchill, then prime minister, outside No 10 in June 1943
voicesA C Benson called him 'a horrid little fellow', George Orwell would have shot him, but what a giant he seems now, says DJ Taylor
News
i100
News
An asteroid is set to pass so close to Earth it will be visible with binoculars
news
Arts and Entertainment
Benedict Cumberbatch has spoken about the lack of opportunities for black British actors in the UK
film
News
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Austen Lloyd: Private Client Solicitor - Oxford

Excellent Salary : Austen Lloyd: OXFORD - REGIONAL FIRM - An excellent opportu...

Austen Lloyd: Clinical Negligence Associate / Partner - Bristol

Super Package: Austen Lloyd: BRISTOL - SENIOR CLINICAL NEGLIGENCE - An outstan...

Recruitment Genius: Sales Consultant - Solar Energy - OTE £50,000

£15000 - £50000 per annum: Recruitment Genius: Fantastic opportunities are ava...

Recruitment Genius: Compute Engineer

Negotiable: Recruitment Genius: A Compute Engineer is required to join a globa...

Day In a Page

Syria crisis: Celebrities call on David Cameron to take more refugees as one young mother tells of torture by Assad regime

Celebrities call on David Cameron to take more Syrian refugees

One young mother tells of torture by Assad regime
The enemy within: People who hear voices in their heads are being encouraged to talk back – with promising results

The enemy within

People who hear voices in their heads are being encouraged to talk back
'In Auschwitz you got used to anything'

'In Auschwitz you got used to anything'

Survivors of the Nazi concentration camp remember its horror, 70 years on
Autumn/winter menswear 2015: The uniforms that make up modern life come to the fore

Autumn/winter menswear 2015

The uniforms that make up modern life come to the fore
'I'm gay, and plan to fight military homophobia'

'I'm gay, and plan to fight military homophobia'

Army general planning to come out
Iraq invasion 2003: The bloody warnings six wise men gave to Tony Blair as he prepared to launch poorly planned campaign

What the six wise men told Tony Blair

Months before the invasion of Iraq in 2003, experts sought to warn the PM about his plans. Here, four of them recall that day
25 years of The Independent on Sunday: The stories, the writers and the changes over the last quarter of a century

25 years of The Independent on Sunday

The stories, the writers and the changes over the last quarter of a century
Homeless Veterans appeal: 'Really caring is a dangerous emotion in this kind of work'

Homeless Veterans appeal

As head of The Soldiers' Charity, Martin Rutledge has to temper compassion with realism. He tells Chris Green how his Army career prepared him
Wu-Tang Clan and The Sexual Objects offer fans a chance to own the only copies of their latest albums

Smash hit go under the hammer

It's nice to pick up a new record once in a while, but the purchasers of two latest releases can go a step further - by buying the only copy
Geeks who rocked the world: Documentary looks back at origins of the computer-games industry

The geeks who rocked the world

A new documentary looks back at origins of the computer-games industry
Belle & Sebastian interview: Stuart Murdoch reveals how the band is taking a new direction

Belle & Sebastian is taking a new direction

Twenty years ago, Belle & Sebastian was a fey indie band from Glasgow. It still is – except today, as prime mover Stuart Murdoch admits, it has a global cult following, from Hollywood to South Korea
America: Land of the free, home of the political dynasty

America: Land of the free, home of the political dynasty

These days in the US things are pretty much stuck where they are, both in politics and society at large, says Rupert Cornwell
A graphic history of US civil rights – in comic book form

A graphic history of US civil rights – in comic book form

A veteran of the Fifties campaigns is inspiring a new generation of activists
Winston Churchill: the enigma of a British hero

Winston Churchill: the enigma of a British hero

A C Benson called him 'a horrid little fellow', George Orwell would have shot him, but what a giant he seems now, says DJ Taylor
Growing mussels: Precious freshwater shellfish are thriving in a unique green project

Growing mussels

Precious freshwater shellfish are thriving in a unique green project