Is This the Machine That Will Finally Find Life On Mars?

From Little Green Men to Little Green Bugs

The 1970s and early ´80s were the heyday of extraterrestrial life-think of celebrity astronomer Carl Sagan´s books and Tonight Show appearances, the Spielberg movies Close Encounters of the Third Kind and E.T. throbbing with adolescent yearning to connect with . . . something out there. But for all the countless hours that radio astronomers spent trying to intercept electromagnetic frequencies from some superintelligent intergalactic civilization, the yield to date has been exactly zip. Popular culture moved on to other obsessions.

But NASA and its independent contractor the SETI (Search for Extraterrestrial Intelligence) Institute haven´t abandoned the search; they´ve merely refocused it. The new watchword is "astrobiology": looking for microorganisms on other planets. The search for little green men has given way to the search for little green bugs.

If bacteria are lacking in E.T. cachet, at least there is an outside shot at finding them on Mars, our second-closest planetary neighbor and, in many respects, the most Earth-like. "If life did start twice, independently, in our solar system," says NASA senior research scientist Chris McKay, "that tells us that life starts pretty easily in the universe. If so, why shouldn´t it develop intelligence somewhere else?" The discovery of little green bugs could be considered the biological equivalent of the Copernican revolution, when humans realized that the universe didn´t revolve around them. What if we´re not alone?

The device that stands the best chance of answering that question is goofy-looking Zo. Because life on Mars is a needle-in-a-haystack proposition, we need a detection system that can reduce the haystack to manageable size. Zo´s is the leading technology under development that combines a nimble robotic platform with a scientific instrument that detects microscopic life. No need to collect and time-consumingly analyze soil samples; just point, shoot, and keep on rolling, about 20 times as fast as the rovers Spirit and Opportunity currently trundling around Mars. Zo marks its search territory in canine fashion, spraying special dyes on the ground to make organic molecules fluoresce, then trying to capture them on camera.

In a real Mars mission, scientists won´t have a bunch of engineers on location to look under the hood, so com-
munication between the Chile-based field team and the Pittsburgh-based science team is kept to a minimum. Still, they must collaborate closely. Magnified by geographical distance, the natural gulf between engineers and life scientists is given every chance to widen.

The scientists in Pittsburgh throw around words like "mystical" and "nirvana"; they tend to focus on the far-out implications of the mission. French-born SETI planetary geologist Nathalie Cabrol, 42, who heads the science team, dreams that she´ll someday be able to live in a space station on Mars and do planetary science for several years at a stretch-although the most optimistic estimated date for a first human mission to Mars is 2025.

In contrast, the on-the-ground engineers are, well, practical. To them, the Chilean desert is an unusual and pretty cool place to work on a robot, nada mas. "To the scientists, the desert is this ultra-pristine Mars analogue with fascinating little bacteria in the soil," Williams muses. "For them, the rover is just a tool. For us, it´s what we´ve been working our asses off for, 50 hours a week." Zo must drive right through the middle of that intellectual divide.