Deep down within a Canadian mine researchers have made an ancient discovery. They have found the world's oldest water. At a depth of roughly 3 kilometers (1.8 miles), tests have found that the water is at least an impressive 2 billion years old.  

The latest discovery pushes back the date for the oldest known water by at least 500 million years. The previous record was held by water found in the same mine by the same team back in 2013, and came from a depth of around 2.5 kilometers. When the miners dug deeper, the researchers took the opportunity to explore further into the mine and made their current discovery.

The mine is in fact the deepest basal metal mine in the world, as the search for copper, zinc, and silver is taking the miners deeper and deeper into the Earth’s crust. As the mine continues to expand, the researchers are using the tunnels to get a glimpse into what is hidden far below the surface, including searching for ancient water.

“When people think about this water they assume it must be some tiny amount of water trapped within the rock,” Professor Barbara Sherwood Lollar, who presented her findings at the American Geophysical Union Fall meeting, told BBC News. “But in fact it’s very much bubbling right up out at you. These things are flowing at rates of liters per minute – the volume of the water is much larger than anyone anticipated.”

What is more, the vast age of the water is not the only important discovery. When the researchers analyzed the liquid, they found traces of life within it. While they are yet to find actual living bacteria, what they did discover was in effect the fingerprint of life. From this they are able to infer that there has been some form of microbiology living within the water and over a very long time period.

The fact that something has been able to survive, and indeed flourish, within water that is so old and so deep within the Earth has some important implications. While rivers no longer flow on the surface of Mars, there are still pockets of water and ice under the surface. These are nowhere near as deep as the water discovered in Canada, and it is therefore possible that these pockets could provide the conditions necessary for microorganisms to live.