For nearly half a century scientists have searched the sky for radio signals that clearly originated with intelligent life on another planet. All they needed was a glimpse, just a whimper, proving that we are not alone in the universe.
But in all those years, despite the undaunted and sincere efforts of some of astronomy's leading minds, they have found nothing. Not even a hint that E.T. is out there.
In recent years scientists have suggested alternative ways of searching -- analyzing the atmospheres of other planets to see evidence of life, for example -- but there's a new idea in the mix now that could have significant fringe benefits, including, quite possibly, saving the Earth from destruction.
"If we are going to find E.T., I think we are going to stumble across him," said electrical engineer John D. Mathews of Pennsylvania State University in a telephone interview.
Instead of searching specifically for alien intelligence, Mathews said, we need to rebuild the space program with unmanned self-replicating robots that could explore outer space, sending back data that would tell us far more than we now know about our galaxy.
In other words, give up on our current search. And in due time, he said, we just might meet E.T.
Mathews has laid out his ideas for space exploration in a provocative article in the Journal of the British Interplanetary Society. It seems like science fiction, with exploratory robots zipping off from a base on the moon, or an asteroid, to land eventually on other worlds, where they would mine minerals and build manufacturing plants to replicate themselves. The new clones, updated with the latest technology, would blast off again in search of distant planets on the fringes of the galaxy.
The idea itself is not all that new. The brilliant Hungarian-American mathematician John von Neumann envisioned self-replicating robotic explorers decades ago, which became central characters in hundreds of science fiction stories. Von Neumann, incidentally, also coined the term Mutually Assured Destruction (MAD) while working on the Manhattan Project in the development of the atomic bomb.
But if the vision of robots cloning and updating themselves seems impossible, many of the strange ideas that sprang from the fertile mind of von Neumann have proved true, including what many consider the first computer virus.
However, Mathews was attracted to the von Neumann world for reasons far more basic than searching for E.T., which he said "has been elevated to this almost magical, god-like status."
"Why do we want to be in space anyway?" he asked during the telephone interview. "There are two immediate answers. I would like to say it's because we want to go exploring and we like new frontiers and all of that, but I think the fact is we need to worry about getting hit on the head by an asteroid, and we need to worry about the fact that the near-space environment is full of junk."
In case anyone has forgotten, an asteroid is believed to have wiped out the dinosaurs. And some day a lot of the debris left over from the early days of exploration is going to come down, possibly with tragic results.
So we need to get our house in order on both those counts, Mathews argues, and the best way to do that is with robots that can mine necessary resources, manufacture fuel, and send back critical data while cleaning up the celestial neighborhood.