But there was so much that wasn’t in the Viking images, or any other previous views, like the strange, twisted rock layers on the floor of the giant Hellas basin, which resembled pulled taffy. And the bizarre texture of the south polar ice cap, which was riddled with circular pits that made it look like a slice of Swiss cheese. And the fact that places that looked smooth in the old Viking images were revealed as astonishingly rough by MOC, while rough terrain seen by Viking often looked smooth at higher resolution.
Mike Carr, who led the team that had acquired the Viking Orbiter images 20 years earlier, came to San Diego to spend a week targeting MOC with Edgett and Malin. Carr had spent as much time studying Mars as any human being, but the planet revealed by MOC was entirely puzzling to him. Sometimes, as he walked the halls of Malin Space Science Systems, his head buzzing with profound and unsettling questions, he could be heard muttering in his mild Yorkshire accent, “We just don’t understand this! It just isn’t the Mars we understood! I don’t get it!”
EVEN AFTER a couple of years in San Diego, Ken Edgett was still vague in finding his way around the neighborhood he lived and worked in. But when it came to navigating MOC’s Mars, he was absolutely masterful. “He knows Mars better than any other person on the planet,” says Malin. “Way better than me.” Edgett spent almost every waking hour in front of the computer screen in his office, stopping only for fast food from a nearby mall. It got to the point where he could glance at any one of the tens of thousands of images MOC had received and be able to say, aided only by the image ID number, where it had been taken. One of the scientists on Malin’s staff who had helped to develop MOC, a geologist named Mike Ravine, had warned Edgett to pace himself, saying that this mission would be a marathon, not a sprint. But Edgett couldn’t help himself. “It was too cool to peel yourself away,” he said.
And during 1999 the pace of work was absolutely relentless. Each day brought a flood of new images, sometimes as many as 300, to look at. Sometimes he was so busy preparing for the next batch of pictures to be taken that he barely had time to study the ones that had just come in. Every new image had to be submitted to NASA’s archive of planetary data and posted on the Internet within six months after it was received. And on top of everything else, he and Malin were given the added task of photographing landing sites for the upcoming Mars Polar Lander mission; after it crashed in December 1999 they used MOC to search—in vain—for the wreckage.
No wonder, then, that they’d had no time to publish their discoveries in scientific journals. But by the spring of 2000, things had slowed a bit, giving the pair time to write a paper for Science magazine on a discovery that, to Edgett, was the most surprising so far: thousands of features that looked like drainage gullies on the walls of craters, cliffs, and valleys. Each gully had a narrow channel running down the center, and that meant the gullies had to have been carved by a fluid. The only fluid that made any sense was liquid water. The really troubling thing, though, was that these features weren’t relics from some ancient, wetter epoch; they were so fresh that they had to be geologically recent. In fact, Malin later said, “we cannot rule out that some of them are so recent as to have formed yesterday.” But, as everyone knew, Mars was now too cold, and its atmosphere too thin, to allow liquid water to exist. Or was it? Water was the one explanation Malin wanted to avoid, because it went against everything he thought he knew about present-day Mars. But Malin and Edgett ultimately concluded it was the only explanation that made sense. In June, at a packed press conference at NASA headquarters, they announced evidence that water had flowed on Mars in recent times.
That revelation, which stirred both excitement and controversy, was just the beginning. At the end of 2000 they published their discoveries of the complex, layered nature of the upper crust of Mars. Then there was the finding, made public in late 2001 and early 2002, that the mysterious pits in the south polar ice were actually getting bigger, evidence that this supposedly permanent mantle of frozen carbon dioxide was actually disappearing while we watched. “What this tells you,” Malin said in 2004, “is that Mars is experiencing today global warming.” MOC’s Mars is a world in transition, nothing like the changeless fossil it was once thought to be. For Bruce Murray, the planet revealed by his former student’s camera is so surprising that he now calls Mars “the land of broken paradigms.” And Mike Malin, who says Mars is “a puzzle with most of the pieces missing,” still feels humbled in the face of its mysteries.