NASA’s Curiosity rover has detected geological formations with honeycomb-like textures, known as polygonal fractures, in Mars’ “Valle Grande” valley. These structures, measuring between 4 and 8 centimeters in diameter, had been observed in small patches in the past. Their recurrent presence in this new area suggests past environmental conditions that could have favored microbial life on the Red Planet.

Polygonal fractures typically form on Earth when salt-rich mud dries and contracts, creating hexagonal patterns. On Mars, their appearance in “Valle Grande” is particularly interesting because this valley is located in a transitional zone of Gale Crater, where the rover has been investigating the planet’s geological history. The identification of these textures over a larger extent than usual provides new clues about the evolution of the Martian landscape and the presence of liquid water on its surface billions of years ago.

This finding reinforces the hypothesis that Gale Crater hosted a system of lakes and rivers for long periods. Understanding how these polygonal fractures formed on Mars could help scientists determine the composition of the water and sediments present at that time, as well as the duration of wetting and drying cycles. These data are crucial for reconstructing the Martian paleoclimate and assessing the planet's potential habitability in its past.