By Erin Wayman
Drilling more than two kilometers into the ground beneath Canada, geologists have struck scientific gold: pockets of flowing water isolated underground for at least 1.5 billion years and perhaps as long as 2.64 billion years.
The water is rich in hydrogen and methane, which nourish microbes living today near hydrothermal vents on the seafloor. That means the deposits may harbor ancient lineages of life cut off from the surface for eons, the researchers report in the May 16 Nature.
Although the water has not yielded any evidence of life to date, the researchers intend to start looking. And because ancient rocks on Mars share a similar mineral composition, the finding suggests that the Red Planet could also be home to deeply buried life, says coauthor Barbara Sherwood Lollar, a geochemist at the University of Toronto.
The study “makes a good case that if there was ever a biosphere on Mars, then tiny remnants of that biosphere are very likely preserved underground,” says planetary scientist Chris McKay of NASA Ames Research Center in Moffett Field, Calif. But he doesn’t expect imminent confirmation of that proposition. “Considering that after 40 years of Mars exploration we have managed to drill only a few centimeters, it may be a long time before we can follow up on this idea.”