These spider-like shapes, despite their arachnid moniker, don’t crawl on eight legs. Instead, they’re the result of a fascinating interplay between sunlight and carbon dioxide layers accumulated during the Martian winter.

As springtime arrives on Mars, sunlight triggers a transformation. The carbon dioxide ice beneath the surface turns into gas, building up pressure until it bursts through the overlying ice. This explosive release propels dark material upward, forming eerie patterns akin to spider legs, while fracturing layers of ice up to a meter thick.

The gas, laden with dark dust, erupts through cracks in the ice like fountains, showering the surface before settling down. This process creates dark spots ranging from 45 meters to a kilometer across, along with intricate spider-shaped etchings beneath the ice, hinting at subterranean mysteries.

ESA’s ExoMars Trace Gas Orbiter has provided striking images of these spider formations, complementing Mars Express’ observations. These spider sightings, captured by TGO, lie just beyond the scope of Mars Express’ latest image.

In the Mars Express view, these dark spots dot the landscape, stretching across hills and plateaus, with a concentration visible to the left, near the outskirts of the area nicknamed Inca City.

Inca City earned its title for its uncanny resemblance to the ruins of the ancient Inca civilization, with its labyrinthine network of ridges. Discovered in 1972 by NASA’s Mariner 9, this Martian marvel has puzzled and intrigued scientists for decades.

The discovery of these dark streaks, reminiscent of spiders, traces back to the early 2000s, with images from NASA’s Mars Global Surveyor sparking initial curiosity.

Initially, scientists entertained the notion of liquid water as the cause, a tantalizing prospect hinting at possible Martian life. Yet, further investigation unveiled a different story. The streaks’ origin lies in seasonal processes involving carbon dioxide ice sublimation, dispelling the liquid water hypothesis.

As researchers delved deeper, they unraveled the mechanism behind these spider-like features: the seasonal release of pressurized carbon dioxide gas, carrying dark sand and dust, sculpting Martian landscapes into otherworldly forms.

Through the lens of various Mars missions, our understanding of the Red Planet’s enigmatic processes continues to evolve, painting a clearer picture of its dynamic surface.