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ShareNov. 10, 1998 — Writer: Kristen Vecellio
Source: Steven Benner, (352) 392-7773, benner@chem.ufl.edu
GAINESVILLE, Fla. ---Traditional science fiction has aliens who speak some form of English or resemble humans. The problem is, chances are slim that non-terrestrial life will have such earthling-like traits.
Chemists at the University of Florida hope to overcome that obstacle by figuring out what alien life might look like.
"We cannot expect the future of space exploration to be like that in Star Trek, where the aliens almost always resemble human actors," said Steven Benner, chemistry professor at UF and the principle investigator for the new Astrobiology Institute funded by NASA. "This makes it difficult to know how to recognize non-terrestrial life."
NASA and UF have teamed up with institutions such as Harvard University, University of California at Los Angeles, Woods Hole Marine Biological Laboratory and the University of Colorado to form a virtual Astrobiology Institute to study the origin and evolution of life in the galaxy.
UF's job, designing experiments to look for life without knowing exactly what life looks like, can be difficult.
Benner and five UF chemists are looking for a universal feature in genetic material that also may be found in potential Martian life. Benner said DNA has evenly spaced, repeating negative electrical charges along it. These repelling charges allow the DNA molecule to be copied, an essential process in genetics. These charges could be a "universal" trait.
"While the rest of the genetic molecule will vary from life form to life form and from planet to planet," Benner said, "they will, we expect, all have the repeating, spaced electrical charges." The life-on-Mars question has been around for centuries but gained renewed interest two years ago when meteorites collected from Antarctica were identified as rocks from Mars. One rock displayed what some scientists felt might be fossilized remains of microscopic organisms once living on the Red Planet.
This discovery still remains controversial, but it has accelerated interest in exploration of Mars.
Benner said most people don't believe there are organic molecules on Mars based on experiments done in 1976 by the Viking mission. Organic molecules are thought to be necessary for life.
"Based on a general understanding of organic chemistry and an understanding of organic chemistry in the cosmos, we can predict what the principle organic molecules should be on the surface of Mars," Benner said. "These, as it turns out, would not have been detected by the Viking 1976 experiments."
Benner is a member of the Mars Architecture Definition Team working at the Jet Propulsion Laboratory in Pasadena to design a vehicle to go to Mars, collect samples and return to Earth.
He said space missions to Mars are now scheduled for every two years, with the first to be in 2003 with the Athena Rover to study the surface of the planet.
The fascination with the possibility of life on Mars dates back to at least the late 19th century when astronomer Percival Lowell championed the idea that irrigation canals covered the entire planet. His theory was discarded in 1965 when the U.S. spacecraft Mariner 4 discovered there was only a very thin atmosphere.
In 1976, the Viking missions, whose primary use was to search for life on Mars, found none.
"We know a good deal about what life on Earth looks like at a chemical level," Benner said. "We then try to generalize from that distinguishing features of living systems on Earth that are likely to be universal in all living systems."
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