Searching for a microscopic E.T. Christian Science Monitor

Norman Pace strides across his office and returns with a small rock plucked from the frigid wastes of Antarctica. The University of Colorado biologist, who is credited with finding organic life in some of the harshest places on Earth, turns the stone in his hand and says, “A fundamental question is whether there is photosynthesis going on, on the surface of Mars,” itself a frosty wasteland. “If there is life on Mars, this is what you’re going to see,” says Dr. Pace, pointing to a colored layer in the rock, once home to millions of microorganisms.