"It's always exciting when you talk about liquid water on present-day Mars," Ashwin Vasavada, project scientist at NASA for the Curiosity mission, told Space.com. However, he declined to say how confident he is in the study's claims, because he isn't an expert in the kind of radar imagery the team used. "It's exciting because of any implications it might have for the habitability of Mars." [Geometry Helps Solve the Mystery of Mars' Water]
And it's too early to say what precisely those implications may be. Scientists still need to confirm the discovery itself and understand precisely what characteristics that water may have, which will require missions that have yet to be designed, much less launched.
Water below the ice?
The new research builds on more than three decades of theorizing by scientists about the chances that water lurks below Mars' polar caps, just as it does here on Earth.
That idea was first proposed by Steve Clifford, now a planetary scientist specializing in water on Mars at the Planetary Science Institute based in Arizona, who was not involved in the new research. He was inspired by scientists' studies of lakes below the Antarctic and Greenland ice sheets here on Earth, he told Space.com. Those lakes are created when heat from within the planet melts the glaciers in patches. He thought a similar scenario could be happening below the ice caps on Mars — we just didn't have any way to see below the ice.
The new research attempted to do just that using radar data gathered by an instrument called MARSIS, which uses pulses of radar to study the planet's ionosphere and interior structure. It has been orbiting the planet aboard Mars Express, a European spacecraft, since 2003.