Astrobiology, as the term implies, is a melding of disciplines. NASA is attempting to cut across scientific fields, from astronomy to zoology, from ecology to molecular biology, and from geology to genomics. By doing so, scientific research, technology and missions beyond Earth's confines are focused on the goal of discovering the thread of life in the Universe.

"Humans are occupying every land domain on Earth," said NASA's Lynn Harper, special assistant to the Director of Astrobiology and Space Research. She said that, despite the hostility of an environment, like a desert or polar region, while those may be harsh locales that limit the number of people occupying them, humans do find ways to expand into those niches.

"The historical message here on Earth is that people do leave their place of origin and go elsewhere. The expansion of humanity into space seems to be something embedded in our nature," Harper told space.com.

Mark Adams, a historian from the Univ. of Pennsylvania, said that astrobiology embodies a longstanding dream of Western culture. He noted that "the future of every species is to go extinct."

But Adams added that humanity has reached a new epoch by having the ability to take control over its own evolution and to "shape our own destiny" and "give ourselves a future."

"The primary driver behind planetary science and astrobiology is the idea of exploration. We are trying to understand who we are as a species and how we fit into our world," said Bruce Jakosky, a space scientist at the University of Colorado in Boulder.

However, Jakosky warned that "science for its own sake no longer has the cachet that it once had," pointing out that without public and Congressional support, "astrobiology runs the risk of becoming a marginal activity." Troublesome, he said, is the ongoing debate about creationism versus evolution, observing that either the public does not understand this view of science or does not accept it.

But how do you mesh biology into astrobiology? Start sending life to Mars, said Ames space scientist, Chris McKay. There is a paradigm shift now underway, he said, in attempting to understand the potential for survival and biological evolution of life beyond the planet of its origin.

"We're going to purposely send life to Mars, and I don't mean human life. We need biological demonstration missions. That is going to be a conceptual leap," McKay said. One idea now being discussed is sending a flower to Mars and actually growing it on the red planet. Such an experiment, he said, would be contained, but would be proof positive that life on Earth can grow on another world.

Mars is not now an abode for life, McKay believes, but "if there is life on Mars, it's not doing very well. It's hanging on waiting for us to come and rescue it."

Ecologist Margaret Race, a principal investigator for the SETI Institute in neighboring Mountain View, Calif., waved a cautionary flag regarding the purposeful planting of biology on Mars. She emphasized the protection against biological cross contamination and recognition of ethical issues surrounding the search for extraterrestrial intelligence (SETI).

Guidelines are critical and prudent, Race noted, as researchers contemplate invasive activities on extraterrestrial bodies where life may be discovered. "When will we say that there is no life on Mars so that we can step in with those next experiments. That is where no amount of science can give us the answers. We are entering into a new realm," she said.

Indeed, when pondering the prospects for locating extraterrestrial life, the public appears to have already reached a SETI readiness level. The fast-paced nature of today's scientific finds, and the onslaught of evermore powerful technology has, in a sense, preconditioned society for accepting the "we are not alone" status of the cosmos, said John Billingham, senior scientist for the SETI Institute.

"There is an increasing realization of what Carl Sagan taught us all over so many years. We are made of star stuff," Billingham said. The incredible advances in technology, the spreading story of SETI, the exploration of Mars and the promise of possible life on Jupiter's moon Europa - collectively it makes for a continuing and strengthening social interaction with astrobiology, he said.

"You put it all together, and the new millennium to boot, that's a good mix," Billingham said.