Researchers at The Center for Planetary Science have determined, sadly, that aliens were not responsible for the Wow! Signal. Instead, in an article published in Washington Academy of Sciences, they outline their discovery that a comet was likely responsible for the naturally occurring radio transmission.
The research team noticed that the frequency of the Wow! Signal closely matched the radio waves naturally emitted by hydrogen, called the hydrogen line. They then determined that a comet called 266/P Christensen emitted a strikingly similar signal, likely due to its hydrogen cloud. After that, it was just a matter of showing that the comet was indeed in the vicinity of the Sagittarius constellation in 1977.
This is probably a blow to alien enthusiasts who have used this signal to bolster their beliefs that we aren't alone in the universe. It's worth noting, though, that finding the facts behind mysterious signals is a good thing; it improves our science and our knowledge about the universe. And it doesn't disprove the existence of alien life. It just means we have to keep searching. The truth is out there.