Curiosity finds evidence of wet and dry seasons on ancient Mars

The evidence came from photographs snapped by the NASA bot of the dry, dusty Martian surface marked by a series of hexagonal shapes that indicate mud covered the surface before drying and cracking.

The cracks themselves are mere centimetres deep, which the boffins said suggests short wet-dry cycles "were maintained at least episodically in the long term," which would be yet another favorable condition for the past emergence of life on Mars.