The 13th Floor

Aliens Speaking Through Radio Waves: The History of the Wow! Signal

In one of my previous articles, I discussed underwater sounds which may possible have come from enormous underwater creatures yet to be discovered aka The Bloop.  This time we put our ear to space for what might just be a communication from other worldly creatures in a galaxy far, far away. “The Wow! Signal” was heard on August 15, 1977 at Ohio State University. Astronomers using a radio telescope called The Big Ear encountered the signal while searching for extraterrestrial life on other planets. The signal, which originated from the constellation Sagittarius, was so surprising that astronomer Jerry Ehman circled the signal on the data printout and wrote “Wow!” next to it, thus giving it the name the Wow! signal.

Ohio State University’s Big Ear telescope began construction in 1956. It took five years to complete and was activated for the first time in 1963. Its original purpose was to perform the Ohio Sky Survey, an astronomical survey of extragalactic radio sources. It completed that original mission in 1971 before being repurposed to search for extraterrestrial radio signals.

The Big Ear at Ohio State

A decade before Big Ear’s second mission was underway, Cornell physicists Philip Morrison and Giuseppe Cocconi speculated in 1959 about the possible existence of extraterrestrial radio signals from civilizations attempting to contact Earth. They hypothesized that aliens would use a frequency of 1420 megahertz because it is naturally emitted by hydrogen, the most common element in the universe.

In 1977, Ehman was working as a volunteer on Big Ear’s SETI program. His job was to analyze the data which was processed and printed out by an IBM 1130 mainframe computer. On August 15, 1977, while going through stacks of perforated printer paper, Ehman came across an astonishing signal spike. Ehman circled the alphanumeric signal, 6EQUJ5, and wrote next to it “Wow!”.

The precise location of the signal’s origin remained uncertain. Big Ear was designed with two feed horns pointed in slightly different directions to allow for the earth’s rotation. If the signal had been heard by both horns, then it would have been easier to locate the signal’s origin. However, only one horn heard the noise. Because of this, scientists were left with two possible origins for the signal, both of them being in the constellation Sagittarius. The nearest star in Sagittarius is Ross 154, a star 9.69 light years or 2.97 parsecs from Earth. Sagittarius also lies in the galactic center of the Milky Way, where it is at its densest. Therefore, it contains many star clusters and nebulae.

In the months that followed, Ehman attempted to relocate the signal, but failed to do so. In 1987, data analyst and astronomer Robert H. Gray attempted to find the signal using the META array at the Oak Ridge Observatory, but also failed to do so. For the next several years, many more tried to find the signal all to no avail. In 2012, the Arecibo Observatory beamed a digital stream towards the area where the signal originated. The transmission included 10,000 twitter messages with the hashtag #chasingUFOs. It also included video vignettes from celebrities like Stephen Colbert and Leila Lopez conveying their salutations. So lets hope whoever receives those messages isn’t annoyed by 140 character message limits and enjoys the comedic stylings of Stephen Colbert. Having the world conquered by aliens because some jokes bombed would be an interesting end-of-civilization story.

The signal has not been heard again despite multiple attempts over the decades. The Big Ear was decommissioned and disassembled in 1998 to make room for the expansion of a nearby golf course. The signal’s origin still remains a mystery, and to this day the Wow! signal is still the strongest evidence that alien radio transmissions exist and are reaching us.