NASA Researcher, Rabbinical Scholar Mull A "Second Genesis" On Mars

In the search for life beyond the Earth, the most promising site in the solar system are deep deposits of Martian ice that have been frozen for billions of years, perhaps preserving microbial specimens that could be retrieved intact for laboratory analysis, a NASA scientist said in a lecture at AAAS.

Christopher P. McKay, a research scientist at NASA's Ames Research Center in California, said that spacecraft that have orbited or landed on Mars have proven the Red Planet once had the essential elements for the formation of life: liquid water and an atmosphere with carbon and nitrogen.

If life did evolve on Mars, it has long since been killed by ultraviolet radiation, said McKay. But for scientific purposes "dead is okay," he said, because the deep cold of Mars' permafrost could have preserved remains of that life.

The most interesting finding of future missions to Mars would be a "second Genesis," evidence of life that had originated independently from life on Earth, he said during a lecture organized by AAAS's Dialogue on Science, Ethics and Religion.

"Our question is not: Was there life on Mars?" said McKay. "Our question is: Was there a separate life on Mars? We really are looking for aliens."

In response to McKay's lecture, Rabbi Nancy Fuchs-Kreimer, director of the Religious Studies Program at the Reconstructionist Rabbinical College, said a "second Genesis" would present some theological problems for some religions.

For Jews, the discovery of extraterrestrial life would raise some interesting religious questions. For instance, Fuchs-Kreimer said, the Jewish Sabbath is based on a seven-day week with cycles of day and night every 24 hours. If a planet with intelligent life has another type of light-dark cycle, when would the Sabbath be observed?

But she said the prospect of researchers finding a Genesis beyond the Earth does not threaten her religious beliefs because "our God is big enough to accomplish it all.

"The primary Jewish theological position is that God is in charge of it all," she said. "Whatever you find, God will grow as big as we need God to be for the information you bring us."

McKay said if exploration of Mars shows the planet did have water and all the other requirements for life for a long period and, yet, had no "second Genesis," then that would be an argument against the theory of life evolving naturally without other influences.

Such a finding would not be absolute proof against the theory for the unaided formation of life, "but it will certainly give me reason to pause," he said.

"The religion folks will love that," said Rabbi Fuchs-Kreimer.

McKay has proposed a Mars mission that would include drilling 10 meters or more into frozen Martian soil to extract specimens that might contain evidence of ancient, long-dead microbes.

"Imagine the future," he said in the 22 September lecture at AAAS headquarters in Washington, D.C. "We drill down in Mars and pull up a core of ice-rich permafrost with gooey brown stuff in it. We could then ask the question: 'Was that stuff ever alive?'"

Laboratory tests could look for amino acids and other biological compounds that are common to all life on Earth. That could confirm that the material was once alive.

"If it's alien, none of these (laboratory) methods will work," he said. "We need to develop a more general way to search for life."

The NASA researcher said that a case can be made to not send humans to Mars until scientists can conduct a thorough, robotic search for evidence of Martian life. Otherwise, the evidence could be obscured by contamination.

"With humans on Mars, contamination is inevitable," he said. "If we go to Mars and find that there was a second Genesis, what about all that contamination? It would be bad if we had to admit that in our first step out into the universe, we came across an alien life form and we killed it."

McKay said that robotic rovers sent to Mars have already carried bacteria there. Sterilizing levels of ultraviolet radiation on the Martian surface would kill any exposed Earth microbe. But if it is shielded, such as inside a rover, bacteria could still be alive, although unable to reproduce due to the Mars' deep, dry cold.

If the mission is designed with this in mind, then contamination of Mars, even from human surface exploration, he said, can be reversed if we decide it is necessary. "We decontaminate Mars by removing all material that could shield UV light," said McKay.

The more serious Earth-contamination threat comes from drilling beneath the Martian surface.

"Anything we do in the subsurface of Mars has to be rigorously sterilized," McKay said. Earth microbes introduced into underground aquifers of Mars are shielded from the lethal UV radiation and could reproduce, he added, causing "irreversible contamination."

AAAS established the Dialogue on Science, Ethics, and Religion (DoSER) in 1995 to facilitate communication between scientific and religious communities. DoSER builds on AAAS's long-standing commitment to relate scientific knowledge and technological development to the purposes and concerns of society at large. The objectives are to contribute to the level of scientific understanding in religious communities and to promote multidisciplinary education and scholarship of the ethical and religious implications of advancements in science and technology.

Paul Recer

4 October 2005