The Gediz Ceres Ridge is believed to be the remnant of a powerful ancient debris flow and is a long-sought destination by the rover's science team. Three billion years ago, during the last wet period on Mars, powerful debris flows carried mud and boulders down a huge mountain. The rubble formed a fan shape that was later eroded by the wind into a towering ridge, leaving an intriguing record of the Red Planet's watery past.
NASA's Curiosity captured this 360-degree panorama while parked beneath the Gedizwallis ridge (pictured, right). After several previous attempts, the rover finally reached the ridge on its fourth attempt. Image source: NASA/JPL-Caltech/MSSS
Curiosity's Ridge Journey
Now, after three attempts, NASA's Curiosity Mars rover has reached the ridge and captured the landscape in a 360-degree panoramic mosaic. Previous attempts had been hampered by razor-edged "crocodile-back" rocks and steep slopes. After one of its toughest climbs ever, Curiosity reached an area on August 14 where it could study the long-sought ridge with its 7-foot (2-meter) robotic arm.
A view captured by the Mastcam on NASA's Curiosity Mars rover as it parked next to the ridge of Gedez Canyon. Image credit: NASA/JPL-Caltech/MSSS/UC Berkeley
"After three years, we finally found a location on Mars that allows Curiosity to safely access a steep ridge," said Ashwin Vasavada, Curiosity project scientist at NASA's Jet Propulsion Laboratory in Southern California. "It's exciting to be able to reach out and touch rocks that have been brought from high on Mount Sharp that we will never be able to access with Curiosity."
Discovery on Mount Sharp
The rover has been climbing the lower portion of 3-mile-high (5-kilometer-high) Mount Sharp since 2014, uncovering evidence of ancient lakes and streams along the way. The different layers of the mountain represent different eras of Martian history. With the arrival of Curiosity, scientists are learning more about how the landscape changes over time. Gediz Vallis Ridge is one of the last features of the mountain to form, making it one of the youngest geological "time capsules" Curiosity will see.
Mount Sharp rises approximately 3.4 miles (5.5 kilometers) above the floor of Gale Crater. This oblique view of Mount Sharp was created by combining elevation and imaging data from three Mars orbiters. The perspective is toward the southeast. Gale Crater is 96 miles (154 kilometers) in diameter. Source: NASA/JPL-Caltech/ESA/DLR/FUBerlin/MSSS
Rare insights and future explorations
The rover stayed on the ridge for 11 days, busy taking photos and studying the composition of dark rocks that apparently came from elsewhere on the mountain. The debris flow that helped form the Gediz Ceres Ridge brought these rocks, some as big as cars, down from the formations high on Mount Sharp - and others lower on the ridgeline. These rocks provide Curiosity with a rare opportunity to examine material coming from up the mountain.
From November 15 to 17, 2022, which is the 3653rd to 3655th Martian day of this mission, NASA's Curiosity rover used the ChemCam instrument to view the boulders on the Gediz Ridge. The boulders, thought to have been swept down by mudslides in ancient times, may be the youngest evidence of liquid water Curiosity has seen on Mount Sharp. Image source: NASA/JPL-Caltech/LANL/CNES/CNRS/IRAP/IAS/LPG
After the rover reached the ridge, scientists also got their first up-close look at the eroded remnants of a geological feature known as a debris flow fan. Debris flow fans are common on both Mars and Earth, but scientists are still studying how they form.
"I can't imagine what it would be like to witness these events," said geologist William Dietrich, a member of the mission team at the University of California, Berkeley. "Giant rocks are torn out of the mountains high up, rushing down the slopes, and forming a fan shape below. The results of this event will push us to better explain such events, not only on Mars, but even on Earth, they are also a natural disaster."
The path of NASA's Curiosity rover as it passed through lower Mount Sharp is shown here as a pale line. Different parts of the mountain are color-coded; Curiosity is currently near the top of Gediz Vallis Ridge, which is shown in red. Image source: NASA/JPL-Caltech/ESA/University of Arizona/JHUAPL/MSSS/USGSAstrogeologyScienceCenter
On August 19, the rover's Mastcam captured 136 scene images of Gediz Vallis Ridge. After these images were stitched into a mosaic, they provided a 360-degree view of the surrounding area. The panorama shows Curiosity's route up the mountainside, including through the "Marked Belt Valley" where evidence of an ancient lake was found.
While scientists are still poring over images and data from Gediz Ridge, Curiosity is already moving on to its next challenge: finding a path to a river channel above the ridge so scientists can learn more about how and where water once flowed down Mount Sharp.
More information about tasks
Curiosity is being built by JPL, managed by the California Institute of Technology (Caltech) in Pasadena, California. JPL is leading the mission on behalf of NASA's Science Mission Directorate in Washington.