When viewed from above, these tightly grouped deformations, which can be more than 3,300 feet (1,000 meters) wide, look like a hoard of spiders scurrying across the Martian landscape.

Every spring, creepy black 'spiders' sprout up on Mars as buried carbon dioxide ice releases dusty geysers of gas. New ESA images show the phenomenon has begun in the strange Inca City formation.