In an unexpected discovery that could change scientists' understanding of Mars’ geological history, NASA's Curiosity rover has revealed elemental sulfur crystals inside a rock that was crushed under one of its wheels while moving across the Red Planet's surface in an area where researchers did not expect to find this element in such form.

The discovery came as the rover continued its exploratory journey through the lower slopes of Mount Sharp within Gale Crater, where a rock suddenly broke under its wheels, revealing bright yellow crystals of pure sulfur, a scene that scientists described as one of the most exciting discoveries during the Curiosity mission, which has been ongoing for over a decade.

This discovery is particularly significant because scientists had previously observed minerals containing sulfur on Mars, such as sulfates, but finding elemental sulfur in this location was a complete surprise, as this type of sulfur forms under specific geological and chemical conditions that differ from those that produce sulfates.

The surprise doesn't end with the rock alone; the surrounding area contains numerous similar rocks, indicating that the sulfur-rich deposits may extend over a wider area rather than being an isolated phenomenon. This gives scientists the opportunity to study a new geological formation that could provide unprecedented insights into Mars’ history.

Researchers hope that the new samples will help determine the conditions under which these deposits formed, whether as a result of ancient volcanic activity, interactions between groundwater and rock, or thermal and chemical changes that occurred millions or even billions of years ago.

Elementary sulfur

The presence of elementary sulfur is a scientific puzzle because current geological models did not predict its appearance in this area. Therefore, scientists believe that the discovery does not confirm previous theories but rather leads them to reconsider their understanding of the evolution of the red planet and the processes that shaped its surface over time.

According to NASA, the discovery highlights the importance of direct exploration of Mars' surface, as such fine details cannot be observed from orbit; they require mobile scientific laboratories like Curiosity, which is capable of analyzing rocks and studying their composition up close.

Since its landing in Gale Crater in 2012, Curiosity has provided strong evidence that Mars once had lakes, rivers, groundwater, and environments that may have been suitable for microbial life. With each new layer it ascends on Mount Sharp, the rover reveals a new page of the planet's geological history.

NASA believes that the sulfur-rich region discovered by the rover could become one of the most important sites to study during the next phase of the mission. Comparing these rocks with nearby formations may help determine whether these deposits resulted from a local geological event or are part of a broader process affecting a large area of Mars.