On 15 August 1977, Ohio State University’s Big Ear Telescope received a strong narrow-band radio signal which appeared to come from the Sagittarius constellation.
The signal bore the expected hallmarks of Extra-Terrestrial origin.
The signal sequence lasted for as long as 72 seconds, during which Big Ear was able to observe it. Ever since, despite all the attempts,there has been no trace of it whatsoever.
Till date, many theories have been given in an attempt to explain the origin of the signal. But still, there is no actual evidence as to where it came from or what exactly caused it.
We are certain of one thing though; the emission didn’t have a near-Earth origin. It was a deep space emission and was emitted by someone or something located in the direction of Sagittarius.
At the time of the observation, the Big Ear radio telescope was only adjustable for altitude (or height above the horizon), and relied instead on the rotation of the Earth to scan across the sky.
Given the speed of Earth’s rotation and the spatial width of the telescope’s observation window, the Big Ear could observe any given point for just 72 seconds.
A continuous extraterrestrial signal, therefore, would be expected to register for exactly 72 seconds, and the recorded intensity of such signal would display a gradual increase for the first 36 seconds—peaking at the center of the observation window—and then a gradual decrease as the telescope moved away from it.
All these characteristics are present in the Wow! signal.
Some arguments have been made suggesting that a comet or some other object might have emitted the signal, but we haven’t been able to mathematically put any such object, at that particular moment, in the direction the signal originated from.
If it were emitted by an alien civilization, we should have been able to receive more such signals.
It created a big controversy 43 years ago, and it still continues.
P.S. Can be primitives. Can be Galactics. Can be Type 4, 5 or 6 civilization. Or can be nothing! All options are on the table.