Martian ‘spiders’ are small, dark, spider-shaped features up to 1 km (0.6 miles) across. The leading theory is that they form when spring sunshine falls on layers of carbon dioxide deposited over the dark winter months. Thanks to new experiments, a team of scientists at NASA has, for the first time, re-created those formation processes in simulated Martian temperatures and air pressure. Examples of the ‘Kieffer zoo’ features proposed to be...
