The Opportunity Mars rover came across this only 8m large relatively young crater on its way to the large Endeavour crater

Mars Exploration Rover Opportunity has visited and photographed two craters informally named for the spacecraft that carried men to the moon 41 years ago this week.

Opportunity drove past "Yankee Clipper" crater on Nov. 4 and reached "Intrepid crater" on Nov. 9. For NASA's Apollo 12, the second mission to put humans onto the moon, the command and service module was called Yankee Clipper, piloted by Dick Gordon, and the lunar module was named Intrepid, piloted by Alan Bean and commanded by the late Pete Conrad. The Intrepid landed on the moon with Bean and Conrad on Nov. 19, 1969, while Yankee Clipper orbited overhead. Their landing came a mere four months after Apollo 11's first lunar landing.

"The Apollo missions were so inspiring when I was young, I remember all the dates. When we were approaching these craters, I realized we were getting close to the Nov. 19 anniversary for Apollo 12," Rice said. He sent Bean and Gordon photographs that Opportunity took of the two craters.

The images are available online at http://photojournal.jpl.nasa.gov/catalog/PIA13593 and http://photojournal.jpl.nasa.gov/catalog/PIA13596. Intrepid crater is about 20m in diameter. Yankee Clipper crater is about half that width.

After a two-day stop to photograph the rocks exposed at Intrepid, Opportunity continued on a long-term trek toward Endeavour crater, a highly eroded crater about 1,000 times wider than Intrepid. Endeavour's name comes from the ship of James Cook's first Pacific voyage.

During a drive of 116,9m on Nov. 14, Opportunity's "odometer" passed 25km. That is more than 40x the driving-distance goal set for Opportunity to accomplish during its original three-month prime mission in 2004.

Mars Exploration Project Manager John Callas, of NASA's JPL, said, "Importantly, it's not how far the rovers have gone but how much exploration and science discovery they have accomplished on behalf of all humankind."

At the beginning of Opportunity's mission, the rover landed inside "Eagle crater," about the same size as Intrepid crater. The team's name for that landing-site crater paid tribute to the lunar module of Apollo 11, the first human landing on the moon. Opportunity spent two months inside Eagle crater, where it found multiple lines of evidence for a wet environment in the area's ancient past.

The rover team is checking regularly for Opportunity's twin, Spirit, in case the increasing daily solar energy available at Spirit's location enables the rover to reawaken and resume communication. No signal from Spirit has been received since March 22. Spring began last week in the southern hemisphere of Mars.