Some astronomers think detecting an extraterrestrial radio signal is a matter of when, not if. What goes on in the immediate aftermath of such a discovery? Here's what happened the last few times we thought we'd heard from E.T.
The first, and most famous, potential E.T. signal is the so-called Wow! signal. SETI researcher Dr. Jerry Ehman found the signal in 1977 with Ohio State University's Big Ear radio telescope. The signal appeared as a coded set of intensity readings, 6EQUJ5, which Ehman circled and wrote, "Wow!" next to on the printout. It was a notable signal because it was much more intense than galactic background noise, and was found very close to the frequency astronomers expect to find alien transmissions, 1420 MHz. That's the frequency hydrogen atoms resonate at, and hydrogen is the most common element in the universe.
What happened after the signal was found? Not much. Scientists tried to find the signal again to help pinpoint its origin, but no one has ever been able to track it down. It was apparently not a continuous signal, because only one of the Big Ear's two detectors caught it. Over the ensuing decades, hours and hours of telescope time have been devoted to scanning that area of the sky, and nothing like the Wow! signal has been heard there since. It's still a very mysterious thing, because most terrestrial origins have been ruled out. That leaves secret military or government technology, or a natural phenomenon in space that we haven't found yet. Or aliens.
Another E.T. signal was found using the massive Green Bank radio telescope in West Virginia in the late 1990s. It was clearly artificial, broadcasting in a pattern of uniformly spaced frequencies. Unfortunately, it turned out to be NASA's Solar and Heliospheric Observatory. It took the better part of a day to figure that out, however, so in the meantime, excited astronomers were calling colleagues and friends to tell them the news. Word of the discovery made its way to Ann Druyan, Carl Sagan's widow. She called the New York Times' science reporter, who thankfully did not yell, "Stop the presses!" Instead, he called astronomers to confirm – by that time, they'd realized it was a false alarm. How will the government react when we detect alien signals from space?
That situation is most interesting for what didn't happen. For one thing, black helicopters did not descend instantly on Green Bank. Scientists were not spirited to undisclosed locations. A shroud of government secrecy did not enclose the entire operation. There was no conspiracy. In fact, the types of officials who could actually pull off something like that are pretty far out of the loop. They don't really hang with the astronomy crowd.
The astronomers also didn't follow the voluntary protocols accepted by SETI researchers. Those protocols say: first, call the U.N., certain world leaders, and rich people who give a lot of money to SETI. Then, hold a press conference. Those are pretty non-binding protocols. If it happened today, we'd probably call it the OMG! Signal, named for the Tweet sent out by the researcher who first found it.
So we know how scientists would react (pretty much like you and I would). How would the world react? Hysteria? Religious revival? Looting? We can learn both from the Wow! signal and the recent discovery of arsenic-based life by NASA researchers. The world simply waited to see what happened next. Scientists went about their business of confirming the information, which, as we saw in the Wow! case, could take years and years. Doubt has already been cast on the arsenic research. After a brief period of excitement and media interest, it will fade from view until something gives us a reason to pay attention again. And there might not be much of that coming either, because even if we can definitively confirm an alien signal, we'll have no idea what it's saying. That could take decades to decipher, if it's possible at all.