Michal Filippi
Honeycombs like the one pictured above plaster the surface of rocks around the world, but how they form has long been a mystery. Now it seems they may be created by the action of water and salt.
Honeycombs have been found on rocks at many places on Earth, and there is evidence for them on Mars. Jiří Bruthans of Charles University in Prague has studied them in the Czech Republic, where honeycombs on exposed sandstones create “natural ‘rock cities’ with cliffs and pinnacles”.
Over the years, researchers and enthusiasts have suggested many different origins for these formations, from …
