London: An astronomer believes that the ‘Wow!’ signal received three decades ago, which is believed by many to be proof of alien life, may have come from an interstellar ‘lighthouse’.
The ‘Wow! signal’ was received at 11.16 pm on August 15, 1977 - the night before Elvis died - as a radio telescope in Ohio swept its gaze through the constellation of Sagittarius.
It lasted 72 seconds and earned its name because of the message of disbelief Jerry Ehman, a researcher with the Search for Extra-Terrestrial Intelligence (SETI) programme, scrawled next to the printout recording it.
Since 1982, astronomer Robert Gray has been on a quest to solve the puzzle of the enigmatic blip in the read out of a radio telescope - the like of which has never been seen again since.
Gray, who has just published a book about his attempt to rediscover the signal said he believes it could have come from an alien ‘lighthouse’.
The characteristics of the signal - a rise and fall in its ‘loudness’ were exactly what the alien-hunters had been told to look out for.
Eighteen years previously, researchers had put themselves in the shoes of possible extra terrestrials and tried to work out the best way to attract our attention.
They decided that the most noteworthy signal would be a radio signal at exactly 1,420 MHz. This is the vibration frequency of hydrogen, the most common molecule in the universe.
Everyone agreed that it would be the most widely intelligible way of saying, ‘We’re here - are you?’ When the Wow! Signal came in, its frequency was 1,420 MHz.
With such a massive area of space to cover, the SETI programme had adopted the strategy of sweeping the sky with their radio receivers, meaning that they could only spend a few seconds looking at each spot.
They worked on the assumption they may find an alien ‘beacon’ or broadcast that was on all the time, and that all they would have to do is survey the sky to find it.
Gray, an economist by trade, believes the conventional search for an alien ‘beacon’ that is always transmitting is misguided.
Such a transmission would require vast amounts of energy to operate, the equivalent of thousands upon thousands of Earth-style power plants.
“They might use some other cheaper strategy - brief periodic broadcasting, a sweeping lighthouse beam, or other methods,” the Daily Mail quoted Gray as telling theatlantic.com.
“The people who do SETI, who are often but not always astronomers, have a mindset that it’s sensible to look for the really strong signal that is going to be there all of the time.
“Because my education is not in astronomy or engineering, it may be that I bring a kind of practicality to this, especially as it concerns the practicality and economics of what it takes to broadcast a signal like that,” he said.
His book, ‘The Elusive Wow’, published by Palmer Press, is out now.