Cape Town-11104-Businessmen and wonmen discuss matters and share ideas at the 62nd International Astronautical Convention held at the Convention Centre in Cape Town. Photo:Ross Jansen

Richard Davies

Sapa

HALF a century of scanning radio waves from deep space for signs of intelligent life has produced just one enigmatic trace, an expert said yesterday.

The well-known “Wow!” signal, detected 25 years ago by a Search for Extraterrestrial Intelligence (Seti) researcher at Ohio State University’s so-called “Big Ear” radio telescope, had proved a curious one-off, said Seti League executive director emeritus Paul Shuch.

“One of those things that goes bump in the night and then is gone forever.”

Shuch told the International Astronautical Congress in Cape Town that attempts to detect the signal again – which appeared to come from a region of the sky that lies in the constellation Sagittarius – had drawn a blank.

The “Wow!” signal bore all the hallmarks, at the time of its detection, of having a non-Earth origin.

Researchers finally found themselves looking at two possibilities.

This was after they had ruled out the possibility that the signal could have emanated from Earth and been reflected back from a piece of space debris, or a planet or moon.

“Ultimately, they were left with only two remaining possibilities: either this was a briefly intercepted snippet of extraterrestrial deliberate communication; or, it was a previously undiscovered natural astrophysical phenomena.

“Either of these boggle the imagination. So we were left with an enigma.”

Shuch then revealed a third possibility. He had hesitated to speak about it before retiring because of his professional reputation.

“I looked at the date on the computer print-out: August 15, 1977. I said, ‘Wait a minute, I know that date!’. That was the night that Elvis died. Just maybe, this was the Mother Ship calling him home!” he said, to loud audience laughter.

Shuch said afterwards that Seti researchers had come to realise that intelligent life was probably very rare.

“When Seti science first started, in the early 1960s, we optimistically assumed this would be a short duration project and show immediate success… It’s taken us this half a century to come to the conclusion that it’s not going to be so easy. Civilisations are more rare, more elusive.”

On what he thought the odds were of discovering intelligent extraterrestrial life, he conceded there might come a time, in “another generation or two, or century or two”, when researchers might reluctantly conclude that humankind was alone in the cosmos.

“That point, when it comes, if it comes, will be a very significant point for humanity, because that, too, is an astounding result,” Shuch said.

“To conclude that we are the only game in town will have profound implications with regards to our view of our place in the cosmos and our respect for our world.

“Of course, I’d like not to be alone, but if we are, I’d like to know that, too. Or, at least, know there’s a high probability that we are.”

Asked if he thought life on Earth might be unique, he said this was hard to answer.

“It’s a tough call because we just don’t have the data to know. Let’s put it this way: I’ve already concluded that radio-emitting civilisations within the Milky Way galaxy are rare. Whether they don’t exist, I’m not prepared to say, but yes, they’re rare,” said Shuch.

“And the fact that they’re rare is in itself a significant discovery. We’ve done enough research at least to know that had they been common, we’d have found them already,” said Shuch.