LOS ANGELES (AP) — The face of Mars is dotted with a maze of channels, pointing to possible ancient megaflood episodes.

Now scientists peering below the surface have uncovered the first evidence of underground channels apparently created by flooding — a finding that's expected to further illuminate the role of water in Mars' history.

Using a ground-piercing radar sensor aboard the Mars Reconnaissance Orbiter, a team of scientists created 3-D maps of an equatorial region known as Elysium Planitia and the channels that run underneath the plains.