“The yardang layer looks out of place. It’s the wrong color, the layers tilt at an odd angle, and it almost appears plastered on,” said Ashwin Vasavada, Curiosity project scientist of NASA’s Jet Propulsion Laboratory in Southern California. “But that’s what makes it exciting to reach. No one is sure exactly what created this layer, but one idea is it may be ash deposited by ancient volcanic eruptions.”

Curiosity is in the second year of its fifth extended mission, which started with an exploration of the spiderweb-like boxwork ridges. The rover will spend most of the next year or so driving through layers enriched with sulfates and carbonates, both signs of ancient drying on the surface. Sometime in 2027, scientists hope to reach the base of the yardangs, where Curiosity will be able to use its robotic arm to collect one-of-a-kind data on these mysterious features.