Mars Is Hiding Oceans of Water

Scientists searching for signs of water on Mars say they've found enough of it to cover the entire planet to a depth of a mile—but it's not a resource that thirsty Martian colonists could easily access. According to a study in the journal Proceedings of the National Academy of Sciences, the water is in fractured igneous rocks in Mars' midcrust, 7 to 12 miles below the surface. Scientists already knew there was water on Mars in ice at the poles, but this is the first time liquid water has been detected, the BBC reports.

• How it was found. The findings were made by analyzing data from the InSight lander, which recorded 1,319 earthquakes between 2018 and 2022, to assess what material seismic waves were traveling through. "These are actually the same techniques we use to prospect for water on Earth, or to look for oil and gas," says study co-author Michael Manga, a professor of Earth and planetary science at the University of California, Berkeley,

• Where it came from. The study's lead author, Vashan Wright of the University of California San Diego's Scripps Institution of Oceanography, says the water probably seeped from rivers, lakes, and possibly oceans on the surface of Mars billions of year ago as the planet's atmosphere thinned, the AP reports. He says that if the readings from InSight's location near the equator is representative, the water could cover the surface of Mars in an ocean around a mile deep.
• The implications for life. Wright says it's possible that some form of life could exist in the water. "It's certainly true on Earth—deep, deep mines host life, the bottom of the ocean hosts life," he says, per USA Today. "We haven't found any evidence for life on Mars, but at least we have identified a place that should, in principle, be able to sustain life."

• Accessing it will be a challenge. UC Berkeley notes that since it's difficult to drill a hole even a half-mile deep on Earth, the water is much too far below the surface to supply a future Mars colony. "The findings pinpoint another promising place to look for life on Mars, however, if the reservoir can be accessed," the university says. "For the moment, it helps answer questions about the geological history of the planet."

(More Mars stories.)