Seasonal 'spiders' emerge on Mars' surface

July 16 (UPI) -- In late winter on Mars, 'spiders' begin to emerge on the Martian surface. NASA's newest featured image, captured earlier this year by the Mars Reconnaissance Orbiter, showcases the spindly geological formations.

"Araneiform terrain" is the scientific term for the surface spiders. They appear as the sun returns to Mars' South Pole. As the warm solar rays heat the surface, carbon dioxide ice beneath the surface begins to sublimate, turning from a solid to a gas.

When local pressure mounts inside the subsurface ice cap, pockets of gas can explode upwards, exploding dust in all directions and leaving a spider-like blast signature on the ground.

The seasonal geological process is unique to Mars' South Pole and not found anywhere on Earth.