When NASA eventually sends humans to Mars — a mission that might not take place for another decade or more — there’s a good chance they’ll be targeting a region of the planet where water ice is readily available. With that in mind, it makes sense for NASA to figure out what locations on the Red Planet have the most ice.

Now, a new research effort using a pair of high-tech NASA machines has revealed a wealth of water ice hiding just below the surface across a fairly large swath of the planet. The ice is so close to the surface that the researchers say it could be easily accessed with simple tools.

The researchers used data gathered by the Mars Climate Sounder on the Mars Reconnaissance Orbiter, and the Thermal Emission Imaging System instrument on the Mars Odyssey orbiter. Both of these tools can detect heat, and combined data from both tools allowed the scientists to generate a map of where water ice is trapped beneath the surface and at what depth.

In the image below, cooler colors indicate water ice nearer the surface. The box represents an area that would be suitable for a crewed Mars mission to land, according to the scientists.

“You wouldn’t need a backhoe to dig up this ice. You could use a shovel,” Sylvain Piqueux of NASA’s Jet Propulsion Laboratory, and lead author of the study, said in a statement. “We’re continuing to collect data on buried ice on Mars, zeroing in on the best places for astronauts to land.”

The study, which was published in Geophysical Research Letters, is just one piece of a huge puzzle that will ultimately help NASA decide where to send its astronauts once such a mission becomes feasible.