The pictures showed a surface smooth and dark red in some places, and strewn with fragmented slabs of light bedrock in others. Bounce marks apparently left by the rover's air bags when it landed were clearly visible.
"I am flabbergasted. I am astonished. I am blown away. Opportunity has touched down in an alien and bizarre landscape," Steven Squyres, the mission's main scientist, said early Sunday. "I still don't know what we're looking at."
Mission members hooted and hollered as the images splashed on a screen in mission control at NASA's Jet Propulsion Laboratory in Pasadena. Gov. Arnold Schwarzenegger was there with his wife, Maria Shriver, to watch the drama unfold, and walked through mission control shaking hands with the scientists.
But the celebration was tempered by the problems affecting the other rover, Spirit, reports CBS News Correspondent Steve Futterman.
On Wednesday, Spirit developed serious problems, cutting off what had been its own steady flow of pictures and other scientific data.
Spirit is still far from operating at full strength, and there is no guarantee NASA scientists will solve the problem.
If they do, it will probably take several weeks.
JPL director Charles Elachi said other NASA spacecraft, including Voyager, Magellan and Galileo, recovered from even graver problems.
NASA began receiving the first of dozens of black-and-white and color images from Opportunity about four hours after its apparently flawless landing. Mars at the time was 124 million miles from Earth.
"The pictures just blow me away. We've certainly not been to this place before," deputy project manager Richard Cook said.
Swaddled in protective air bags, Opportunity plunged into the Martian atmosphere at more than 12,000 mph and bounced down on Mars at 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, said Chris Jones, director of flight projects at JPL.
The six-wheeled rover landed at 12:05 a.m. EST in Meridiani Planum, believed to be the smoothest, flattest region on Mars. It lies 6,600 miles and halfway around the planet from where Opportunity's twin, Spirit, landed on Jan. 3.
Initial analysis of the images suggested Opportunity landed in a shallow crater. Its low rim shouldn't block the rolling robot once it gets going, Squyres said.
"It's smooth sailing to the horizon," he said.
The rover's path off its lander also appeared unobstructed, unlike Spirit's landing, when a deflated air bags blocked its planned route to the martian surface, mission manager Matt Wallace said.
Together, the twin 384-pound rovers make up a $820 million mission to seek out geologic evidence that Mars was 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.
NASA administrator Sean O'Keefe broke open a bottle of champagne and toasted the mission.
"As the old saying goes, it's far better to be lucky than good, but you know, the harder we work the luckier we seem to get," O'Keefe said, adding "no one dared hope" that both rover landings would be so successful.
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.
NASA launched two rovers to double its chances of successfully landing on Mars.
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.