NASA’s Curiosity rover has captured a stunning 360-degree view of the Gediz Vallis Ridge, a significant geological formation on the Red Planet that holds clues to its watery past. The ridge preserves a record of robust ancient debris flows three billion years ago during one of the last wet periods on Mars. The space agency’s car-sized robot struggled to reach the ridge, blocked by rocks with sharp edges and steep slopes, but made it on its fourth attempt on August 14. Curiosity’s Mastcam took the images.
The panorama shows a rugged landscape that is more colorful than the previous terrain viewed by the robot. It also reveals the presence of a sandstone layer rich in salts, which suggests that water once covered large parts of the Red Planet. The sulfates have also helped form grooves in the rock like ripples in water, and mission scientists believe waves lapping on the surface of a shallow lake created the undulations. The movement on the top of the water churned up sediment at the bottom, and the resulting texture is called a “combed” texture.
This latest discovery further supports the idea that water stayed on the surface of Mars for very long periods, possibly for the planet’s entire history. This would allow for the accumulation of organic material and a wide range of biological processes to develop, including life. In the future, the team hopes to find other places with a similar history of stability.
Curiosity’s next big challenge is to find a path to the channel above the ridge, which will offer more insights into how water flowed down Mount Sharp, a 3-mile-tall mountain that the Rover has been climbing since 2014. It took many attempts to get to the Gediz Vallis ridge, as it took a lot of work for the robot to navigate its way up the lower parts of the mountain because of the steep slopes and rocks with sharp edges.
After completing its studies at the ridge, Curiosity will drive to another wind-carved valley to investigate a pile of rocks and other materials that appear to be washed down from higher up on the mountain in a wet landslide. The Rover is looking for a place to drill into the rock layers and extract samples.
Scientists say that this panorama and the data from the Gediz Vallis ridge are just the latest examples of how Mars is providing unprecedented insight into its past. The robot is examining rock layers that indicate the existence of lakes and streams. Curiosity has also uncovered evidence of a drier environment in an area called Marker Band, which is layered with sulfates and other minerals that suggest it once had salty water that dried to a trickle.
The mission, led by NASA’s Jet Propulsion Laboratory in Pasadena, Calif., is funded by the agency’s Science Mission Directorate. Malin Space Science Systems in San Diego built and operates the Rover’s Mastcam instrument.