( Get the facts about previous evidence for an underground lake on Mars.) But if these results bear out, a liquid region at this scale on modern Mars has enormous implications for the potential for life, past or present. If something similar is found on Mars, then “we shouldn’t be surprised,” says Jani Radebaugh, a planetary scientist at Brigham Young University who was not involved with the work.

On Earth, groundwater is a hidden sea locked up in sand, soil, and rocks. It’s far too early to say with any certainty, but there is a chance that this layer could represent a global reservoir of liquid water. What’s more, the lander has picked up on a very peculiar electrically conductive layer, about 2.5 miles thick, deep beneath the planet’s surface. In addition to the odd magnetic pulsations, the lander’s data show that the Martian crust is far more powerfully magnetic than scientists expected.

For more, read ‘Taking the Pulse of the Red Planet’ in the November 2018 issue of National Geographic Magazine. Learn about the three distinct ways this groundbreaking mission will study the deep interior of the red planet in the latest video from Decoder. On November 26th, 2018, NASA's InSight spacecraft is set to touch down on Mars after completing a 205-day orbit in space.

Face of mars ghost