Observations collected by NASA’s Curiosity rover over 3.5 years have revealed that oxygen levels in an ancient Martian lake differed between shallow and deep water.
And, researchers say this phenomenon is also common in lakes on Earth.
The discovery is a step toward better understanding whether Mars was ever able to support life, as this type of environment could have created ‘multiple opportunities for different types of microbes to survive.’
While it remains unknown if life ever existed on the Martian surface, researchers say reconstructing its environment is critical in assessing the possibility, according to the Daily Mail.
The layered rock at the site of the stratified lake, indicates the shallow water at Gale Lake was richer in oxidants than deeper water.
‘We’re learning that in parts of the lake and at certain times, the water carried more oxygen,’ said Roger Wiens, a planetary scientist.
‘This matters because it affects what minerals are deposited in the sediments, and also because oxygen is important for life.
‘But we have to remember that at the time of the Gale Lake, life on our planet had not yet adapted to using oxygen – photosynthesis had not yet been invented.
‘Instead, the oxidation state of certain elements like manganese or iron may have been more important for life, if it ever existed on Mars.
‘These oxidation states would be controlled by the dissolved oxygen content of the water.’
According to the researchers, the stratification means the lake would have different environmental conditions at once, varying with the depth.
This means it could have sustained different types of lifeforms, the researchers say.
‘These were very different, co-existing environments in the same lake,’ said lead author Joel Hurowitz.
‘This type of oxidant stratification is a common feature of lakes on Earth, and now we’ve found it on Mars.
‘The diversity of environments in this Martian lake would have provided multiple opportunities for different types of microbes to survive.’
Recently, scientists determined that Mars was covered in water for far longer than previously thought.
This, they say, means life could have been there remarkably recently.
Lighter-toned bedrock that surrounds cracks and fissures in the surface suggests the red planet had life-sustaining liquid for a prolonged period of time.
The presence of halo-like rings of silica in rocks indicates that groundwater was still flowing within the rocks for long after the lakes dried out.
N.H.Kh