NASA's Opportunity rover celebrated 11 years on Mars Saturday (Jan. 24), and the robot's handlers are marking the occasion with a gorgeous panoramic photo that Opportunity took of its Red Planet home.

Opportunity landed on Mars on the night of Jan. 24, 2004, a few weeks after its twin, Spirit, made its Red Planet debut. The rovers were tasked with three-month missions to search for signs of past water activity on the Red Planet. Both Spirit and Opportunity found plenty of such evidence, and then kept rolling long after their warranties expired.

Spirit stopped communicating with Earth in 2010 and was declared dead a year later, but Opportunity is still going strong. The robot has been exploring the rim of the 14-mile-wide (22 kilometers) Endeavour Crater since August 2011, and it crested a rise on the rim known as Cape Tribulation earlier this month. [Latest Mars Rover Photos from Opportunity & Spirit]

NASA's Mars rover Opportunity captured the photos that make up this panorama from the top of Cape Tribulation, a segment of the rim of Endeavour Crater, in January 2015. This version of the panorama is in false color, to highlight differences in surface materials.
NASA's Mars rover Opportunity captured the photos that make up this panorama from the top of Cape Tribulation, a segment of the rim of Endeavour Crater, in January 2015. This version of the panorama is in false color, to highlight differences in surface materials.
Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
For more than 10 years the robots have roved across Mars, making exciting discoveries about water in the planet's past. <a href="http://www.space.com/24394-mars-rovers-spirit-opportunity-explained-infographic.html">See the Mars rovers Spirit and Opportunity worked in this SPACE.com infographic</a>.
For more than 10 years the robots have roved across Mars, making exciting discoveries about water in the planet's past. See the Mars rovers Spirit and Opportunity worked in this SPACE.com infographic.
Credit: by Karl Tate, Infographics Artist

Opportunity took a number of photos with its panoramic camera while at the summit of Cape Tribulation. Mission team members combined some of these images into a mosaic, which NASA released Thursday (Jan. 22) to mark the 11-year anniversary.

Opportunity held its robotic arm so that a small American flag printed on the rover would be visible in the photos, NASA officials said.

"The flag is printed on the aluminum cable guard of the rover's rock abrasion tool, which is used for grinding away weathered rock surfaces to expose fresh interior material for examination," agency officials wrote in a description of the image. "The flag is intended as a memorial to victims of the Sept. 11, 2001, attacks on the World Trade Center in New York."

"The aluminum used for the cable guard was recovered from the site of the twin towers in the weeks following the attacks," they added. "Workers at Honeybee Robotics in lower Manhattan, less than a mile from the World Trade Center, were making the rock abrasion tool for Opportunity and NASA's twin Mars Exploration Rover, Spirit, in September 2001."

Opportunity isn't celebrating the anniversary atop Cape Tribulation. The rover left the location on Jan. 17 to head for a spot mission scientists dubbed Marathon Valley, because Opportunity will have traveled the equivalent of a marathon — 26.2 miles, or 42.2 km — on Mars by the time it gets there.

Opportunity's odometer currently reads 25.86 miles (41.62 km). The rover has driven farther on the surface of another world than any other vehicle. Opportunity broke the off-world driving record last year; it had been held by the former Soviet Union's remote-controlled Lunokhod 2 rover, which racked up 24.2 miles (39 km) on the moon in 1973.

While Opportunity is still a highly capable machine, the golf-cart-size rover is showing some signs of age. Its robotic arm is a bit arthritic, for example, and Opportunity recently began having issues with its flash memory — the kind that can store data even when the power is off. Mission team members are testing out some potential software fixes for the memory problem.

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