Mars may have a lot of water, but it’s too deep to drain.

Using seismic data from NASA’s InSight Mars lander, planetary scientists have found evidence of a vast underground water reservoir deep in the interior of Mars. They estimate it contains enough liquid water to cover the entire planet with oceans one to two kilometers deep (PNAS, Aug. 12).

This discovery sounds like good news for potential future Mars colonies, but all that water is stored in cracks and pores in rocks halfway down the planet’s crust, at a depth of between ten and twenty kilometers. On Earth, even drilling just one kilometer is a challenge.

In their research, the scientists used a mathematical model of rock physics similar to those used on Earth to map groundwater and oil reserves. In doing so, they concluded that the best way to explain the InSight data is a deep layer of fragmented igneous rock saturated with liquid water.

There is plenty of evidence that there was once plenty of water on Mars, but it almost completely disappeared over three billion years ago, when the planet lost almost all of its atmosphere.

Planetary scientists have been trying for years to figure out where all of Mars’ water went. Since the amount of water currently stored in the planet’s polar caps is so small, it was suspected that most of the water had disappeared into space. However, new research now suggests that much of Mars’ water did not escape, but simply seeped into the crust. (E)

Scientists find oceans of water on Mars. It’s too deep to tap.