In 1977, astronomer Jerry Ehman discovered a mysterious signal when working with Ohio State’s “Big Ear” telescope in Delaware. When Ehman first saw the signal on a printout, it was so large and unusual that he circled it and wrote “Wow!”, thus giving the signal its name. It’s also been passed around as possibly the best evidence in support of those who believe alien life is out there.
The Wow! Signal was 30 times stronger than usual background radiation and was broadcast at the same frequency with which hydrogen glows. Some astronomers believe this is the best frequency to look for alien signals, leading conspiracy theorists to claim that the Wow! Signal is in fact a message from extraterrestrials.
Astronomers at the time knew the signal could not have come from Earth, and they believed the signal had come from a region of space near the constellation Sagittarius.
Since the signal’s discovery in 1977, scientists have attempted and subsequently failed to explain its origins, however, recent evidence from Antonio Paris, an astronomy professor at St. Petersburg College, suggests the signal was due to passing comets — not life beyond our planet.
The Center for Planetary Science, which Paris helps run, previously suggested a passing comet and its cloud could be the origin of the Wow! Signal. A comet known as 266/P Christensen was, in fact, in the sky in 1977 when the signal was recorded, however, this was unknown to astronomers at the time.
Using a 10-meter radio telescope, Paris and his team observed the comet as it was passing. The team found that both comet 266/P Christensen and comet P/2008 Y2 (Gibbs) were passing through the particular region of the sky Ehman was observing in 1977. These comets were not known to scientists until 2006. When the radio telescope was moved even 1 degree from the comet in 200 trials by Paris and his team, the signal faded.
Paris admits that it is not entirely proven whether these comets in particular were responsible for the signal, but his team has acknowledged the 1977 Wow! Signal was indeed a natural phenomenon generated by a comet.