On 15 August 1977, astronomers at the Ohio state university were studying the location of a signal in the constellation Sagittarius, as part of the SETI project. Using a Big Ear radio telescope, the origin was found to be from the stars, called chi Sagittarius.
While scanning the skies, at 23:16, the telescope captured an incredibly strong signal, that lasted for 72 seconds and was never detected again. The signal was so strong that one of the astronomers, Jerry Ehman, who first identified the signal, circled the readout and wrote “Wow!” next to the reading, with a red pen.
Since then, this signal remained a mystery for the astronomers. They offered numerous explanations but none of them sat as a valid argument. According to some scientists, asteroids, exoplanets or even signals from Earth are the possible sources behind the signal. But the most widely accepted explanation for this signal was the existence of Extraterrestrial life.
However, professor Antonio Paris, of St Petersburg college, finally solved the mystery behind a 40-year-old signal and -spoiler-alert-it’s not aliens.
Astronomers finally explained the Wow! mystery signal
Astronomer Antonio Paris along with a team at the Centre for Planetary Science worked on this signal for a long time. In 2016, he released a paper along with his fellow astronomer Evan Davies, published in the Journal of the Washington Academy of Sciences. According to his research, comets are the source behind the Wow signal. The team noted two comets, 266P/Christensen and P/2008 Y2 (Gibbs) within the same vicinity where this signal once detected.
Both of the comets have clouds of hydrogen gas accompanying them in the diameter of millions of kilometers. Researchers observed that the frequency of the Wow signal was 1420 MHz, which is the same frequency as that of hydrogen.
Paris along with his team tested the idea, from November 2016 through February of 2017, by pointing the telescope at comet 266P/Christensen, and identified the similar signal. Paris also investigated other comets and observed the same hydrogen clouds, same signals, which makes it evident that even if comet 266P/Christensen is not, some other comet is responsible source for the signal.
Paris research disappointed most of the communities, holding the belief that the signal is a piece of evidence for extraterrestrial life. Paris hypothesis doesn’t convince all of the scientists but is the only solid argument to solve the mystery behind.
Update: The hypothesis doesn’t sit well with all the scientists. One of the scientists from OSU Radio Observatory, where the signal once detected, argued on the presence of comets. According to him, comets were too far from the telescope sightlines to generate such a powerful signal.
“The comet hypothesis, in my opinion, doesn’t work,” Seth Shostak of the SETI Institute concurred in a blog post. Shostak cites the comments of Robert Dixon, who was the director of the Ohio State observatory back in 1977. “Dixon (says) the comets were nowhere near the telescope’s sightlines when the signal was found.”
Oxford physics professor Chris Lintott also raised a tentative eyebrow on Paris work and compiled a list of questions about his work which Paris has planned to review.
Shostak says, “It’s possible (but unproven) that the signal was the result of aliens sending a short ping. If so, we may someday pick up their transmissions again. But it wasn’t a comet … which should be the end of that tale.”
Hence, Shostak argument contradicts with the latest research on this signal and raises serious questions regarding the Paris hypothesis. We might not be able to close the research on this topic but astronomers have got new interesting questions to work on about a mystery that remained unsolved for years.
Sabeeka Zafar is a Bioinformatician-to-be with a passion to be a significant part of the great revolution in the near future in the field of Bioinformatics specifically and that of Science generally. Sabeeka is a social activist, enjoys working with people for the betterment of the society and loves to read and to write.