ESA’s Mars Express has captured images revealing distinctive formations dubbed “spiders” dispersed across the southern polar region of Mars. These features are caused by a fascinating interplay of seasonal changes and geological processes.
During the Martian winter, layers of carbon dioxide accumulate on the surface. Then, with the arrival of spring, sunlight penetrates the surface to cause a transformation.
Solid, Liquid, Gas
The European Space Agency’s Mars Express exploration has found that the bottom layer of carbon dioxide ice transitions directly into gas, exerting pressure and rupturing the overlying ice slabs. As this gas escapes to the surface, it carries dark dust particles, creating towering fountains or geysers that disperse the material across the landscape.
Thousands of the “spiders” can be seen dotting the landscape (European Space Agency / CC-BY-SA 3.0)
The “spiders” observed on Mars are believed to stem from the interaction of sunlight with layers of frozen carbon dioxide on the planet’s surface. Located at Mars’s south pole, where temperatures can plummet as low as –243 degrees Fahrenheit (-152.778 °C) the frigid conditions cause carbon dioxide in the atmosphere to freeze into solid ice.
The ejected dust settles on the surface, forming dark spots ranging from 45 meters (145 feet) to 1 kilometers (0.6 miles) in diameter. These spots serve as indicators of the underlying geological activity. The process also carves intricate spider-shaped patterns beneath the…
