The Curiosity rover has obtained a close look at sulfur crystals on Mars, capturing the first close-up images of this phenomenon. The discovery of pure sulfur crystals on the planet may be related to an ancient asteroid impact, although the circumstances of the discovery are unclear, with some reports suggesting it was an accidental find after the rover crushed a rock. The discovery has sparked interest among scientists, who may soon provide an explanation for the presence of pure sulfur on Mars.