Alum Gilbert Levin had
Ever since we first cast our eyes to the skies, we have been
fascinated by the possibility of life on other planets. Our
neighbor Mars, in particular, holds a special attraction. From
classics to cartoons, we want to believe that life in some form
exists on the red planet, and as we look for them--we imagine--
they gaze back at us.
Recent evidence of ancient fossil microorganisms in meteorites believed to be from Mars catapulted the possibility of life on that planet to starring roles in headlines, talk shows and coffee breaks. Engineering alumnus Gilbert Levin played a critical part in NASA's first attempt over two decades ago to find life, and his recent lecture on the Homewood campus made clear why the issue is still controversial.
Levin holds a bachelor's degree in civil engineering, a master's in sanitary engineering and a Ph.D. in environmental engineering. He founded Biospherics Inc. in 1967, a publicly traded biotechnology firm primarily active in the development and delivery of health information, services and products. A process that Levin developed to indicate quickly and accurately the presence of sludge organisms gave him the idea to approach NASA with a potential experiment to indicate extraterrestrial life. Ultimately, his labeled release experiment was one of three chosen for a biological package to go on NASA's 1976 Viking mission to Mars. Each experiment presented a different scenario to detect life, with the idea that perhaps one would be successful. "The Viking mission was the most spectacular thing NASA has ever done," Levin said, "and the experiments were the most important in the agency's history."
An engaging lecturer who described his research as "stretching from the sewers to the stars," Levin explained his experiment in detail to the audience that crowded into the Schafler Auditorium in the Bloomberg Center for Physics and Astronomy. The experiment revolved around L-cysteine, an amino acid found in proteins. All terran life incorporates L-cysteine, and therefore, its presence means that life processes exist. In essence, the labeled release experiment enticed any microorganisms that might be present in the Martian soil to "eat a meal" and betray their presence by radioactive "breath." The results, repeated over a Martian "week," indicated life.
Reaction from NASA scientists was swift. "The response was 'too much, too soon,'" Levin recalled. "'It must be chemistry mimicking life.'" Scientists believed that the response could have been from the soil itself, and that intense ultraviolet rays and other factors affected the nutrient when it hit the soil. "A biological explanation for the results is easier than a chemical one, but science rightfully takes the conservative way out," Levin said with a smile. Additional tests on board the landers showed a diminished response over time, indicating that the microorganisms could be dying. Levin believes that a purely chemical response would continue to show activity at similar levels over time.
Levin and his team repeated the experiment on Earth soil under Martian-like conditions, and their results were consistent with the Viking experiment's.
The newly discovered fossils and organic compounds in the Martian meteorites only solidify Levin's belief in the accuracy of the labeled release experiment. Over the next decade NASA is sending 10 missions to Mars, but none will carry life-detecting experiments. Levin did have an oxidant experiment on the ill-fated Russian probe, and he has proposed another experiment for NASA's 1998 Surveyor mission.
Levin noted that at least six books will be published soon about life on Mars, so the discussion is far from over. So while there is still no evidence of humanoid-like creatures on the planet, there is at least one individual who believes that "life is probably alive and well on Mars today."
For more information about possible life on Mars and other Mars-related research, browse the Web site located at: http://www.yahoo.com/Science/Astronomy/Solar_System/ Planets/Mars/Life_on_ Mars/.
Go back to Previous Page