PARIS – Scientists said Wednesday they had found life-giving chemicals in water at least 1.5 billion years old, which they are now combing for signs of microscopic organisms that may have survived from a prehistoric age.
The water, isolated in pockets deep underground, is now pouring out of boreholes from a mine 2.4 km beneath Ontario, they wrote in the journal Nature.
“This water could be some of the oldest on the planet and may even contain life,” the team said in a statement.
The similarity between the rocks that trapped the fluid and those found on Mars also raised hopes that similar life-sustaining water could be buried deep inside the red planet, they said. “The findings . . . may force us to rethink which parts of our planet are fit for life,” they added.
The British and Canadian researchers found the water is rich in dissolved gases such as hydrogen and methane that are able to sustain microscopic life not exposed to the sun, as is the case on the ocean floor.
The rocks around the water were dated about 2.7 billion years old, “but no one thought the water could be the same age, until now,” the team said. Analyzing the water’s composition in the lab, the team estimated that it is at least 1.5 billion years old, possibly more.
“Our finding is of huge interest to researchers who want to understand how microbes evolve in isolation, and is central to the whole question of the origin of life, the sustainability of life, and life in extreme environments and on other planets,” said Manchester University researcher and study coauthor Chris Ballentine.
Before this discovery, the only water of this age had been found trapped in tiny bubbles in rock, incapable of supporting life.
The Canadian water has characteristics similar to much younger water, flowing from a mine 2.8 km below ground in South Africa, that is known to support microbes.
Lead author Greg Holland of Lancaster University in Britain said: “We have identified a way in which planets can create and preserve an environment friendly to microbial life for billions of years. This is regardless of how inhospitable the surface might be, opening up the possibility of similar environments in the subsurface of Mars.”