First came the suggestion that an “alien megastructure” had been observed around KIC 8462852, a.k.a. Tabby’s Star. Months later, people were talking about a signal seen by a Russian telescope that some thought was transmitted from the environs of a stellar cousin of the sun. And not long after that, the Cyclopean Arecibo antenna in Puerto Rico reported weird signals that seemed to come from the dwarf star Ross 128, a scant 11 light-years away.

This brisk cadence of celestial surprises might make it seem that we’re on the cusp of proving the existence of extraterrestrials. But just because the crow’s nest announces clouds on the horizon doesn’t mean you’re close to land.

These three claims purporting to show the existence of aliens haven’t panned out. But what happens if some future claim does? What preparations are in place to deal with the discovery of a radio signal or a laser flash that would prove beyond doubt that we have cosmic compeers? Does the government have a plan? Does anyone?

A lot of people think there is a plan. A secret one. A recent survey indicated that 55 percent of the population figure that the discovery of extraterrestrials would be squelched — deep-sixed to prevent widespread panic. Only 19 percent believe the feds would fess up to E.T.’s existence.

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Such a cover-up would be virtually impossible to pull off. There’s no policy of secrecy, and verifying the signal would involve teams of scientists around the world. But leaving that aside, the fact that so many folks believe it's in the works attests to a discouraging lack of trust in both science and the public’s ability to handle the news.

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So what’s the truth about what would happen if we discovered intelligent aliens? Back in 1989, when a now-defunct NASA program to search for extraterrestrial intelligence was gaining steam, protocols were drafted to spell out best practices in case the search proved successful. These were later updated and streamlined by the International Academy of Astronautics SETI Permanent Committee. (Click here to see the revised protocols.)

There are really only three important components to this two-page text. First, the detection of alien life should be carefully verified by repeated observations. Second, the discovery should be publicized. Third, no response should be sent without international consultation.

All that sounds both tame and sane. But there’s an implicit assumption here: namely, that picking up signals from another world will be a Hollywood moment. We assume that it will play out the way it so often does in the movies: stuporous scientists, settling in for another decade or two of fruitless search, are suddenly jolted into wild-eyed excitement as a signal lights up their equipment. Then they spend about 10 minutes turning knobs and shouting at one another, after which they presumably reach into a desk drawer and pull out the protocols.

Actually, they never take this last step in the movies. And they wouldn’t do it in real life either. In the many years of SETI efforts, there have been numerous false alarms in addition to the three noted at the top of this article. And what happens every time is that the media immediately start reporting the story. There is almost always a bit of sensationalism and a few garbled facts, but the news is out there long before the researchers have managed to verify the signal, as specified by the protocols.

That’s the truth of the matter. Really, it is. Sure, speaking of “protocols” has a certain gravitas, but these would only work for a Hollywood-style discovery.

But there’s a deeper question here — one that’s much harder to answer: what would be the long-term effect of learning we’re not alone? Would we give up religion? Would we stop waging war? Would we cower in the face of possible interstellar aggression?

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Facing such questions, social scientists tend to look for historical analogies. For example, what were the consequences when Columbus discovered the American continent (or if you prefer, when the Vikings or Ice Age Asians did)? One problem here is that the analogy isn’t terribly apt. These folks weren’t doing exploration for its own sake. They found something new by accident.

A better analogy might be the discovery of Antarctica or the source of the Nile. These really were exploration efforts. But even these are poor guides to how we should prepare for the discovery of intelligent aliens or anticipate its effects.

Nineteenth-century explorers had no protocols other than to write up their experiences. Furthermore, the eventual consequences of their discoveries were completely incalculable. Do you think Fabian von Bellingshausen, who first saw the Antarctic continent in 1820, could have anticipated that less than 200 years later there would be a research base at the South Pole, or that cruise ships would be taking tourists to these forlorn latitudes?

There is little certainty about what the consequences of finding aliens might be, but there is this: We’ll immediately know something very important. We’ll know that we are neither unique nor special. But if you ask what the legacy of such a discovery will be hundreds or thousands of years from now, there’s simply no way to arrive at an answer that’s either useful or accurate.

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