NASA Rover Nears Rim of Giant Crater on Mars

The Opportunity rover is less than 50 meters from the crater rim and is due to pull up to it later this week

NASA's Mars rover Opportunity is just days away from arriving at the edge of a huge crater after a years-long trek on the Red Planet.

Opportunity has been driving for nearly three years toward the crater Endeavour, an immense scar in the Martian surface about 14 miles (22 kilometers) wide. Now the rover is less than 31 feet (50 meters) from the rim and is due to pull up to it later this week, mission scientists said Monday (Aug. 8).

"I'm totally pumped," the rover's deputy principal investigator, Ray Arvidson, told SPACE.com.

On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

Before it set course for Endeavor in mid-2008, Opportunity spent two years studying a region including a smaller crater named Victoria. Endeavour is 25 times wider than Victoria, which will make it the largest Martian crater ever visited by a spacecraft. [Latest Photos from NASA's Mars Rover Opportunity]

"It really is exploration and discovery in its truest sense," Arvidson said. "We've not been in this kind of terrain ever before."

The rocks at Endeavour crater are the oldest that Opportunity has seen during its seven years on Mars, Arvidson said. Tantalizing hints of clay minerals and other features suggest the region has a different type of ancient history pertaining to water chemistry than other terrain explored by the rover.

"This is a crater that pre-existed any of the sedimentary material that we've seen so far," Arvidson said. Opportunity's visit represents "us trying to get at that early period of time that may have been conducive to life."

Once Opportunity reaches the crater, it could spend years studying the area, if it is up to the task.

Opportunity: A long-lived rover
Indeed, the fact that Opportunity is even moving is an engineering feat. The solar-powered rover is the surviving member of NASA's twin robot team sent to explore different parts of Mars in 90-day missions. [Video: Opportunity's 7 Years of Mars Roving]

Opportunity landed in mid-January 2004, two weeks after its sister robot Spirit. Opportunity has been exploring the vast plains of Mars' Meridiani Planum region, while Spirit set down inside the huge Gusev Crater.

Both rovers lasted for years, but only Opportunity survived the harsh, repeated dust storms, winters and other obstacles on the surface of the Red Planet.

Earlier this year, NASA declared the Spirit rover dead after more than a year of silence from the robot, which became stuck in Martian sand. Mission scientists held a wake for the rover in late July to mark its final passing and honor its accomplishments.

They even named Opportunity's planned arrival point at Endeavour crater after the sister robot. Opportunity is headed to Spirit Point, a vista at the southern point of a ridge called Cape York on the western side of the crater.

"Spirit achieved far more than we ever could have hoped when we designed her," Steve Squyres of Cornell University, the principal investigator for the rovers, said in a statement. "This name will be a reminder that we need to keep pushing as hard as we can to make new discoveries with Opportunity. The exploration of Spirit Point is the next major goal for us to strive for."

The Spirit and Opportunity rovers have made countless discoveries on Mars, including detailed investigations into how flowing water shaped the planet's surface in the ancient past.

Marathon Mars rover
Opportunity, meanwhile, keeps on trucking. Last month its odometer passed the 20-mile (32 km) mark on the road to Endeavour.
"They're just really well-made American machines," Arvidson said.

To be sure, Opportunity has dealt with the pains of aging. One of its six wheels doesn't turn as well as it did, one science instrument (a spectrometer called Mini-TES) has shut down, and the rover has been driving with its robotic arm stretched out a bit because of joint issues, Arvidson said.

Even so, the rover continues to plod along and seems ready for the years ahead at Endeavour.

"All in all, I would like to be that healthy after that number of rover years on Mars," Arvidson said.

• The Best (And Worst) Mars Landings in History
• Opportunity Nears Endeavor Crater - 7 Years and Still Roving
• Photos: Gale Crater on Mars, Curiosity Rover's Landing Site

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American