The Mars rover "Opportunity" has achieved a milestone in its 21-month exploration of the "Red Planet." The rover has reached the rim of the giant Victoria Crater, considered the crown jewel of the Mars mission up until now.
Opportunity beamed back images of the giant, deep impact crater Wednesday to astronomers at the U.S. space agency's Jet Propulsion Laboratory in California.
Pictures of Victoria Crater, which is 0.8 kilometers wide and 70 meters deep, showed thick layers of exposed rock and a bed of rippling sand dunes.
Steve Squyres is with Cornell University in New York, and is the Mars mission's principal investigator.
"My first impression, certainly, when you first see these images is just being awestruck at how spectacular this scene is," he said.
Scientists hope the giant depression in the Martian surface will provide a treasure trove of information about how the planet was formed and whether it could have supported life.
Victoria Crater is located in a flat plateau that lies close to the equator of Mars. It took the solar-powered rover more than 900 days to complete the journey, as it crept along slippery sand. At one point, Opportunity got stuck for five weeks before freeing itself.
A key challenge for scientists now will be figuring out how to get the rover into the crater for a closer look.
Squyres expects many more surprises from Opportunity.
"I think we're going to take more spectacular pictures than the ones that we have just seen today," he added. "But this is the first time that we've seen this stuff, and that makes it special."
Meanwhile, Opportunity's twin rover, Spirit, is halfway around Mars to the south of the equator, taking measurements of the planet's climate.
The two rovers were launched by NASA in 2004, and were expected to perform for three months. But to everyone's surprise, the vehicles continue to navigate the rough Martian terrain and beam back spectacular images.