The search for some kind of life 'out there' has been happening ever since we began to think about it 'out here'. Scientists feel that when we do find life forms elsewhere, they might either be too basic and fundamental, or too advanced to bother about contacting earthlings through the human way of communication.
Hence, the first kind of life forms, ie the primitive forms, could be found on Europa, an icy moon of Jupiter. Its liquid ocean is buried beneath 30 miles of surface ice. Life there would be very primitive---if it exists, say scientists. Even on earth, human beings are dominant, yet their overall biomass is much smaller than "wildly successful organisms" such as bacteria, or even insects.
And in the second instance, if life on other planets are indeed more evolved than ours, how do we touch base with them when they are so remote? Even as radio signals travel at the speed of light, exoplanets are tens of thousands of light-years away, which would make it difficult for us to communicate with them.
Scientists are clear that even if we are able to find primitive extraterrestrial life within the next 20 to 30 years, when we can send missions to other planets, it is not easy to locate technological life. There are all kinds of intelligences that have evolved even on earth, such as dolphins, octopi and crows, along with the great apes. All of them have been found to be intelligent, but not in the technological way that we are aware of. Hence, would it be possible to find a common ground to communicate?
As for the question of why the aliens have not contacted us, scientists are convinced that if life forms on other planets are so advanced that we wouldn't be able to monitor their communication capabilities, they too would not care to communicate with backward civilizations!
Such complex questions and points were thrashed out in a discussion, on "First Contact: Looking for Life in the Universe" at "Star Trek: Mission" New York, discussing human search for extraterrestrial intelligence (SETI).
The discussion was overseen by Dan Werthimer, the SETI chief scientist at the University of California, Berkeley, and Bobak Ferdowski, from the NASA Jet Propulsion Laboratory.
"We are always looking out, Ferdowsi said. "And the further you look, you are also looking into the past." -
"It's a profound question either way," Werthimer said. "If we find the universe is teeming with life, we can learn a lot....If we find out we're alone, that means we'd better take incredibly good care of the precious life here on Earth."
