The source of the mysterious ‘Wow!’ space signal which has baffled astronomers for decades might finally have been found.
The signal was picked up by astronomer Jerry Ehman in 1977 after he had been analyzing radio frequencies from space as part of Ohio State University’s Search for Extraterrestrial Intelligence (SETI) program.
The project’s ‘Big Ear’ radio telescope received a powerful blast of radio waves that lasted for 72 seconds. When Ehman saw it in the data, he circled it on the readout and wrote: “Wow!”
Asteroids, exo-planets, stars and even radio waves from Earth have all been ruled out as possible explanations over the years. The mystery even led some to suggest that it may be a communication from extra-terrestrials.
However, a research team at the Centre of Planetary Science (CPS) in the US believes it has finally solved the 40 year old mystery.
In a paper published in the Journal of the Washington Academy of Sciences, lead researcher Antonio Paris and his team propose that the reading was the result of a hydrogen cloud accompanying a then-unidentified passing comet.
The team first suspected that the signal could have come from a comet when it was discovered that the frequency was transmitted at the exact same frequency as hydrogen (1,420 MHz).
It also explains why the signal was never heard again, as the comet continued traveling through space.
Records from 1977 showed two potential comets that could have caused the signal. One of the contenders, 266/P Christensen, crossed Earth’s path again in February this year and when researchers focused their telescopes on it they got results similar to those produced in 1977.
To verify their results, the team tested readings from three other comets, generating similar findings. The researchers acknowledge that they cannot say with certainty that the Wow! signal was generated by 266/P Christensen specifically, but say it “was a natural phenomenon from a Solar System body.”