is a powerful narrow-band radio signal detected on August 15, 1977, by the Big Ear radio telescope at Ohio State University. The signal consisted of a series of pulses lasting only 72 seconds.

The signal was identified in the recordings by Jerry R. Ehman, the operator of Big Ear, as "6EQUJ5". Since this resembled an exclamation point meaning "Wow!", the signal was dubbed the "Wow! signal".

Ehman noted the signal and thought it might be a message from an extraterrestrial civilization. The signal was detected in just 1 minute of Big Ear's 23-hour observation. The signal was not detected in any other observations.

The Wow! signal was detected at a frequency of 1420 MHz. This frequency corresponds to the natural frequency of radio waves caused by the transition between atomic energy levels of the hydrogen atom. Therefore, the signal was thought to be a message from an extraterrestrial civilization.

The signal was detected at an inclination angle of 23.8 degrees. This inclination angle indicates that the source of the signal is in the region of the Sagittarius star cluster in the constellation of the Big Dipper.

There are many theories about what caused the signal. Some of these theories are as follows:

An extraterrestrial civilization: The signal could be a message from an extraterrestrial civilization. This could be one of the strongest evidence of extraterrestrial life.

A natural source: The signal could also have originated from a natural source. For example, it could be radio waves emitted by a celestial body such as a pulsar or a black hole.

Technical error: The signal could also have been caused by a technical error in the Big Ear itself.

Since its discovery, the Wow! signal has continued to intrigue researchers around the world. Research on the signal is still ongoing.

In 2016, scientists launched a project to identify the source of the Wow! signal. This project focuses on re-analyzing Big Ear's observation data using new technologies. It is known that the project has not yet been finalized. However, it is hoped that the project could help solve the mystery of the Wow! signal.

The Wow! signal is considered one of the strongest pieces of evidence for the existence of extraterrestrial life. Since the signal could be a message from an extraterrestrial civilization, it is of great importance for our understanding of humanity's place in the universe.

Wow! Identifying the source of the signal could provide definitive proof of the existence of extraterrestrial life. This could also accelerate humanity's progress in space exploration and technology.