Photos From Second Mars Rover Dazzle NASA

PASADENA, Calif. - With one rover now ailing on Mars, NASA scientists were thrilled when its identical twin sent dazzling and intriguing photos from the other side of the Red Planet.

Images of a smooth red surface arrived at NASA's Jet Propulsion Laboratory about four hours after the rover Opportunity bounced to a landing late Saturday some 6,600 miles from its temporarily crippled twin, Spirit.

"I am flabbergasted. I am astonished. I am blown away. Opportunity has touched down in an alien and bizarre landscape," said Steven Squyres of Cornell University, the mission's main scientist. "I still don't know what we're looking at."

JPL director Charles Elachi told ABC's "Good Morning America" on Monday that the outcroppings of bedrock visible in the pictures were "particularly exciting."

"For a geologist, this is really a gold mine because that will allow us to learn about the history of the planet and look at the layering in those rocks in a very specific location," he said. "So the scientists are absolutely ecstatic."

Opportunity plunged into the martian atmosphere at more than 12,000 mph and bounced down on Mars just six minutes later, swaddled in protective air bags. It hit with a force estimated to be just two to three times that of Earth's gravity. Engineers had designed it to withstand as much as 40 G's.

The six-wheeled rover landed in Meridiani Planum, believed to be the smoothest, flattest spot on Mars. Opportunity lies 6,600 miles and halfway around the planet from where its twin, Spirit, landed on Jan. 3.

On Sunday, NASA said Opportunity was in excellent health and Spirit was on the mend after a serious software problems had hobbled it.

Initial analysis of the images suggested Opportunity landed in a shallow crater roughly 66 feet across. Its low rim shouldn't block the rolling robot once it gets going, Squyres said.

Opportunity could roll off its lander in 10 to 14 days, mission manager Arthur Amador said. Opportunity's possible targets include a larger crater, maybe 500 feet across, that lies an estimated half-mile from where the spacecraft landed.

The rover's ramp off its lander also appeared unobstructed, unlike Spirit's landing, when a deflated air bag blocked its safest route to the martian surface, said Matt Wallace, another of the mission managers.

Together, the twin 384-pound rovers make up a $820 million mission to seek out geologic evidence that Mars was once a wetter world possibly capable of sustaining life. NASA launched Spirit on June 10 and Opportunity on July 7. Each carries nine cameras and six scientific instruments.

On Wednesday, Spirit developed serious problems, cutting off what had been a steady flow of pictures and scientific data.

Engineers now believe the problem arose with software that manages the file system within the rover's flash memory, project manager Pete Theisinger said. Other possible culprits include broken hardware or solar radiation.

"Spirit is still serious but we are moving to guarded condition," Theisinger said, adding Spirit could resume normal operations in two to three weeks.

NASA sent Spirit to Gusev Crater, a broad depression believed to once have contained a lake. Opportunity was sent to Meridiani Planum, which scientists believe abounds in a mineral called gray hematite.

The iron-rich mineral typically forms in marine or volcanic environments marked by hydrothermal activity. Hematite is common in the red soil found across the Southeastern United States and is frequently used as a pigment, said Doug Ming, of NASA's Johnson Space Center and a member of the science team.

NASA launched two rovers to double its chances of successfully landing on Mars. Both carry identical plaques memorializing the seven astronauts who died aboard space shuttle Columbia nearly a year ago, Opportunity mission manager Jim Erickson said.

As of early Sunday, there were a record five spacecraft operating on or around Mars, including two NASA satellites and one from the European Space Agency orbiting the planet.