After three failed attempts, NASA's Curiosity rover reaches Mars ridge where water left debris pileup

NASA's Curiosity Mars rover has reached the Gediz Vallis Ridge - a destination long sought by the mission team which preserves a record of one of the last wet periods seen on this part of the Red Planet.

Gediz Vallis Ridge was one of the last features to form on Mount Sharp, the 3-mile-tall (5-kilometer) mountain that the rover has been ascending since 2014, making it one of the youngest geological time capsules NASA's Curiosity will see.

The rover reaches this Martian ridge on its fourth try over the course of three years. The previous three attempts were stymied by knife-edged gator-back rocks and too-steep slopes. 

"After three years, we finally found a spot where Mars allowed Curiosity to safely access the steep ridge. It's a thrill to be able to reach out and touch rocks that were transported from places high up on Mount Sharp that we'll never be able to visit with Curiosity," said Ashwin Vasavada, Curiosity's project scientist at NASA's Jet Propulsion Laboratory in Southern California.

Nothing better than stopping for a pic (or 136) after a challenging hike 📸 To create this immersive panorama, my team stitched together 136 images of this region called Gediz Vallis Ridge. It might have taken me 3 years and 4 attempts to get here, but the science is worth it. pic.twitter.com/FthK2VFnkJ

— Curiosity Rover (@MarsCuriosity) September 19, 2023

Following its arrival at the Gediz Vallis Ridge, Curiosity provides scientists with the first up-close views of the eroded remnants of a geologic feature called debris flow fan, where debris flowing down the slope spreads out into a fan shape. This feature is common on both Mars and Earth, but scientists are still figuring out how they form.

The above mosaic is composed of 136 individual images captured by Curiosity's Mastcam on August 19.

Curiosity's next challenge is to investigate the Gediz Vallis Channel, through which water flowed some 3 billion years ago, carrying rocks and debris that piled up to form the ridge.