Scientists have discovered the oldest water ever found on Earth deep in a Canadian mine. The 2 billion-year-old oasis could help us understand the origins of life on our planet and beyond, Gizmodo reports. Researchers from the University of Toronto dug 1.5 miles deep in the Kidd Creek Mine in Ontario to find the water. "We thought, 'Wow,'" geochemist Oliver Warr tells CBC News. "Everything about the water is brand new." They were spurred to keep drilling after spotting slightly younger pools (1.5 billion years old) in the same mine three years ago. What amazed them in particular was that the ancient water wasn't trapped in rock: It was free-flowing—gallons of it. "It’s very much bubbling right up out at you," says team co-leader Barbara Sherwood Lollar, per Gizmodo. The team reported its findings in Nature and last week to the American Geophysical Union.
A chemical analysis of the gases revealed the water's age, and that it contains about eight times the salt of seawater. If sipped, it "would taste absolutely disgusting," Warr tells the CBC. In an intriguing twist, researchers say the prehistoric spring is part of an "interconnected fluid system" deep in the Earth. When the earlier water was found in 2013, Lollar called it "a whole new hydrosphere on the planet," per the National Post. Study of the microbes in the water could reveal clues to life 2 billion years ago on Earth and other planets with similar water pockets such as Mars. "This continues to open up our idea of how much of this planet is habitable,” Lollar tells the Globe and Mail. “And it speaks to the habitability of Mars as well.” (These rocks are 3.7 billion years old.)