Future spelunkers might want to explore caves on the Moon and Mars. Scientists have mapped many cave openings on both worlds. On the Moon, caves could provide shelter from radiation and meteorites for astronauts. On Mars, they could provide shelter for microscopic life that was born on the planet itself.

Orbiting spacecraft have photographed some likely cave entrances on both worlds. They’re big holes in the ground. They may lead to larger chambers on the sides.

On the Moon, the caves probably were excavated by lava flowing below the surface. After the lava disappeared, parts of the empty tubes they left behind caved in, providing the openings. The side chambers could be good places to set up lunar habitats.

Most of the caves on Mars probably formed the same way. But a recent study found eight caves that might have been carved by water. The caves were seen in a region that’s marked by deep channels that carried water in the distant past. The surface water dried up long ago. But the caves could lead to buried pools of ice. If life ever evolved on Mars, it might have survived in those damp locations. So the caves could be a good place to check for life on the Red Planet.

The Moon and Mars line up with the star Aldebaran in tomorrow’s dawn sky. Mars looks like a bright star to the lower right of the Moon. Aldebaran is an even brighter star, about the same distance to the lower right of Mars.

Script by Damond Benningfield