Two European satellites spotted hundreds of dark “spiders” formations in an area of Mars known as “Inca City”, located in the planet’s south polar region.
However, these are not actually spiders but a phenomenon caused by seasonal changes in carbon dioxide ice. In spring, sunlight causes CO2 ice to sublime from solid to gas, breaking up ice layers.
The emerging gas laden with dark dust shoots up through cracks as tall fountains or geysers, depositing dark spots on the surface. This creates the characteristic “spider-like” patterns underneath the ice.
Higher resolution images from the ESA’s ExoMars Trace Gas Orbiter show the dark spots can range from 45m to 1km wide and clearly reveal the intricate spider patterns etched in the ice below.
While seen for decades, scientists only determined their formation mechanism in 2006 involving the transparency of CO2 ice and sunlight warming the dark ground below, causing sublimation of CO2 ice at the bottom of overlying layers.
Source: theweathernetwork
