We have discovered the oldest water on Earth: it is 2 billion years old

Prehistoric water was found in the deepest metal mine on the planet, and its analysis has even opened up hypotheses of life in space.

Water is one of the most precious elements to ensure life on our planet. One of those that absolutely must be preserved, and that is constantly under threat due to pollution and progressive global warming. And if it is true that there are now several space expeditions that have put us in search of H20 even among the stars, few know that another very special journey has led us to discover the oldest source of water on Earth.

In 2013, scientists were convinced that the oldest water on the Earth's surface was in the Kidd Mine, in Ontario (Canada), and boasted the beauty of 1.5 billion years. In reality, only three years later an even more ancient source was discovered, inside the same mine. To find it, it was necessary to go as deep as three kilometers into what is currently the deepest metal mine in the world - but not the deepest spot ever dug by man, into which only two brave people have descended. Instead, the 2013 detection took place at a depth of about 2.4 kilometers in an underground tunnel in the structure, and prompted researchers to investigate further, by the own admission of Barbara Lollar of the University of Toronto:

The discovery showed us how old the flowing water could be, and so it really prompted us to explore further. So in 2016 came the breakthrough, and an interesting analysis of this precious source of life was able to get underway.

The analysis of the gases dissolved in this ancient groundwater - such as helium, neon, argon and xenon -, allowed the scholars to estimate the age of the liquid quite accurately: no less than 2 billion years! This makes the one in the Kidd Mine the oldest known source of water, at least for the time being.

As the researchers explained, in the water at depths including about 2.4 kilometers the sulfate was produced on site in a chemical reaction between the water itself and the rock. This can only mean one thing: the geochemical conditions at this location could support life for even billions of years, despite being effectively isolated from the rest of the planet's surface, where life forms have exploded in a wide variety of shades. Lollar also added that if this can work on ancient rocks on Earth, then similar processes could make the Martian subsurface habitable.

Andrea Guerriero