A strong radio signal from space was picked up in the U.S. This initiated a relentless search for new clues to the existence of high-tech extraterrestrial civilizations.
In 1977, astronomer Jerry Ehman used the large Ohio State University radio telescope to examine space for novel signals. What he picked up that morning on August 15 has been one of the most debated mysteries in the last 42 years, the Wow! signal.
At 03.16 local time, Ehman was pointing the radio telescope at three stellar systems called Chi Sagittarii, in the constellation Sagittarius. Suddenly, the instrument detected a burst of radio waves in a period of 72 seconds. It was a much stronger signal than background noise.
While receiving the signal, the observatory’s computer printed out a series of signs. On the same sheet, Ehman wrote “Wow!”, an expression that might not sum up the surprise of an astronomer who considered the possibility of capturing signals from high-tech extraterrestrial civilizations to be remote.
What the radio telescope had been able to capture boasted his nickname: ‘Big Ear’, referring to his ability to identify radio signals from space.
The impression of the signal contains a large number of numbers and letters in seemingly random order. However, Ehman highlighted the digits “6EQUJ5” with a red pen. He also enclosed a “6″ and “7″ in other columns”.
Deciphering the code
The observatory computer uses the numbers 1 through 9 and then the alphabet A through Z to establish the intensity of the captured signal.
According to the burst, the signal intensity reached “6″ and then increased through the letters until it peaked at “U”. Then it went down to “J” and ended up back on the number scale, at “5″.
Later there was a slight output wave from the main signal. Its intensity corresponded to the numbers “6″ and “7″ highlighted.
In search of the lost signal
After that early morning in 1977, the experts ventured into new searches for this type of signal. In that sense, the SETI Institute was founded in 1984, an organization to search for intelligent life in space.
In spite of the successive efforts, a signal has not been detected again with such intensity. Instead, astronomers encountered cosmic silence.
What is the origin?
With the passing of the years, the hope of once again having ‘traces’ of extraterrestrial civilizations diminished and, with it, skepticism about what had happened increased. Ehman himself said in 2002 that it could be a signal of terrestrial origin that was “simply reflected by some piece of space garbage”.
Later, he stated that it could be related to a mysterious FRB burst (rapid radio burst), extremely short and intense pulses of radio waves. But they were still just estimates.
Until Antonio Paris, professor of Astronomy at St Petesburg College (Florida, USA), who had been studying the Wow! signal for years, appeared in 2016, together with Evan Davies, he stated that the signal could have been caused by one of two possible asteroids, the 266P/Christensen or the P/2008 Y2, which were travelling through the solar system at that time.
These two asteroids were only discovered in 2006, so they were not taken into account during the signal investigations. In addition, due to the cloud of hydrogen that both celestial bodies carry around them, and the fact that this gas is identified by the radio telescope, it was the closest explanation to the truth of the Wow! signal. But Paris had to prove it.
So the researcher spent the last months of 2016 and the first months of 2017 tracking comet 266P with a radio telescope. Apparently, the signals matched that of 1977.
According to Paris, it could also have been any other asteroid wrapped in a cloud of hydrogen. However, the Wow! mystery still lives on and could be revived if another similar signal is picked up.