The clutter of classroom chairs and laptop computers that is the Remote Mission Control room on the fourth floor of an office building at Carnegie Mellon University in Pittsburgh looks like nothing much, which is exactly the point. As far as humanly possible, the team of 20 or so biologists, geologists and instrument specialists who work here are supposed to be living inside Zo´s head. They generally arrive at 1 p.m. to go over the previous night´s data and take care of odds and ends. Then, when the new end-of-day data stream arrives around dinnertime-Pittsburgh and the Atacama are in the same time zone-they go into high gear.
At the end of every working day, Zo takes shots that are later stitched together into a panoramic image. The Pittsburgh scientists pore over this image as if it were a sacred rune. From the landmarks visible in the shot, they must determine the robot´s precise location. This spot becomes the starting point for the next day´s travels, which the Pittsburgh scientists will plan, then upload to a server. Their plan describes the route that Zo should take the next day to access the most biologically propitious spots (on a good day, the robot can cover seven miles). Zo will find its way or collapse trying, and it can choose its own route. The engineers intervene only in emergencies.
To develop each day´s itinerary, the Pittsburgh team plows through instrument data and photographs from Zo´s fluorescence camera. By 1 a.m., or sometimes 2, they call it quits. Most of the scientists are on loan from other institutions, such as the NASA Ames Research Center in California, so they walk together the five blocks to the Holiday Inn, where they decompress in front of their respective TV screens and hope that this time their internal clocks will let them sleep in. "It is sensory deprivation," NASA and University of California at Berkeley biologist Kim Warren-Rhodes says cheerfully.
The routine may sound dull, but the Pittsburgh scientists see themselves as caught up in a great detective story, a search for life whose modus operandi can be summed up as "Follow the water."
The formula for life as we know it is carbon plus water plus an energy source. Scientists think that 3.8 billion years ago Mars plausibly had all three. It had (and has) carbon dioxide in abundance, it almost certainly had water (the famous Martian canyons and channels are thought to have been carved by flowing water), and there is evidence but not yet proof that the polar caps could have trapped geothermal heat that would have first stirred the pot of life. "The point is, Mars has been a geologically dynamic planet, water-enriched . . . you follow me?" says James Dohm, the science team´s burly, excitable geologist. "It´s very tantalizing, so much so it´s hard to sleep at night."
Some 3.5 billion years ago, Mars got a lot less hospitable, but astrobiologists speculate that primitive life could have adapted to the worsening conditions, hiding out in spore form just under the surface or sloshing around in aqueous underground caverns whose existence is suspected but as yet unproved.