The controversial "Wow! signal" appeared on Aug. 15, 1977. Since then, experts are trying to identify its origin. Some even attribute the signal to aliens or extraterrestrial life. However, a new study revealed that it is likely a radio emission from a comet.

An astronomer believes that it could have been emitted by a passing comet that no one knows yet during that time. However, other astronomers remain doubtful as the radio waves do not follow the correct way of how comets emit them.

The "Wow! signal" is the topic of a new study by Antonio Paris, an astronomer from St. Petersburg in Florida. The paper was published in the Journal of the Washington Academy of Sciences.

The paper identified the "Wow! signal" as a bizarre radio emission from some 40 years ago. And contrary to some theories, it did not come from aliens. The signal was linked to the location of a comet called 266/P Christensen that was cataloged and detected during that time. However, the comet was just recently and properly identified in 2006.

Because of the mysterious nature of the "Wow! Signal" there are tons of explanations linked to it. Some say it could also be a spy satellite signal or another unknown natural phenomenon.

"We do not believe the two-comet theory can explain the Wow! signal," Jerry Ehman, the astronomer who discovered the "Wow! signal" in 1977 said in an interview with Live Science.

The radio emission, now believed to have originated from a comet, was first detected by the Big Ear radio telescope at the Ohio State University. The signal lasted for 72 seconds and was a narrow-bandwidth signal, which is unfamiliar to scientists at that time. Some say the "Wow! signal" is a bit similar to radio waves from neutral hydrogen gas in space.

However, what made scientists scratched their heads is the area where the "Wow! signal" came from, which is a relatively noise-free region from other space objects. This heightened the speculations that it may have come from aliens.

But based on the study, Paris say that comets emit radio waves from its surrounding gasses to accelerate closer to the sun. The comet 266P/Christensen is at the right position during the time the "Wow! Signal" was heard in 1977. Paris intends to conduct a deeper analysis on the subject to find out why and how comets emit such bizarre radio waves.

"There have been a handful of studies, but I suspect we are the first to specifically build a 10-meter radio telescope to specifically look at this type of solar system body," he added.