repeated cycles of freezing and thawing of wet soil tagged posts

Textured rows on the ground in this portion of “Perseverance Valley” are under investigation by NASA’s Mars Exploration Rover Opportunity, which used its Navigation Camera to take the component images of this downhill-looking scene. The rover reaches its 5,000th Martian day, or sol, on Feb. 16, 2018. Image Credit: NASA/JPL-Caltech

NASA’s Mars Exploration Rover Opportunity keeps providing surprises about the Red Planet, most recently with observations of possible “rock stripes”.The ground texture seen in recent images from the rover resembles a smudged version of very distinctive stone stripes on some mountain slopes on Earth that result from repeated cycles of freezing and thawing of wet soil. But it might also be due to wind, downhill transport, other processes or a combination.

Opportuni...