Oceans’ worth of water may remain buried in the crust of Mars, and not lost to space as previously long thought, a new study finds.

Prior work found Mars was once wet enough to cover its entire surface with an ocean of water about 330 to 4,920 feet (100 to 1,500 meters) deep, containing about half as much water as Earth’s Atlantic Ocean, NASA said in a statement. Since there is life virtually everywhere on Earth where there is water, this history of water on Mars raises the possibility that Mars was once home to life — and might host it still.