E.T. isn't phoning us, so maybe it's time for us to phone them. That's the idea behind a new initiative called METI (Messaging Extra Terrestrial Intelligence), an offshoot of SETI (Search for Extraterrestrial Intelligence), that intends to begin beaming targeted messages in 2018 to other star systems that might contain intelligent life, reports the New York Times.

For the organization's proponents, the project is a noble one aimed at peaceful contact with our interstellar neighbors, to alleviate some of the cosmic loneliness that comes from living in a universe with such vast empty space. For naysayers, however, there couldn't be a starker contrast. The project's inauguration, they warn, could mark the end of life on Earth as we know it. It amounts to a deranged mouse hoping to make friends by hooting for owls.

"Every single case we know of a more technologically advanced culture contacting a less technologically advanced culture resulted at least in pain," suggested astronomer and science-fiction author David Brin, who has been a vocal critic of any effort like that of METI's to reach out to alien civilizations.

Famed astrophysicist Stephen Hawking has also voiced his concerns, saying in a 2010 documentary series that "if aliens visit us, the outcome would be much as when Columbus landed in America, which didn’t turn out well for the Native Americans."

After being founded in 1984 and after over 30 years of listening for radio signals from intelligent aliens, SETI has yet to discover evidence of E.T. That doesn't mean the project isn't worthwhile, but some researchers think that a more proactive approach could yield better results. That's where METI, which is being led by the former SETI scientist Douglas Vakoch, comes into play. We have to do more than merely listen, suggests Vakoch. If we aren't transmitting our own messages into space, then how can we expect the same from extraterrestrial civilizations? If all we're doing is listening, maybe that's all they're doing as well.

Vakoch's plan is to transmit an ongoing series of messages to star systems with known habitable planets beginning in 2018. The job of scientists at METI will be more than just transmitting the message, though. They also need to figure out what kinds of messages to send, and what their content ought to be. That's a difficult job, and it's one that has been difficult to reach consensus on.

"I think we need to rethink the message process so that we are sending a series of increasingly inclusive messages," Vakoch said. "Any message that we initially send would be too narrow, too incomplete. But that’s O.K. Instead, what we should be doing is thinking about how to make the next round of messages better and more inclusive. We ideally want a way to incorporate both technical expertise — people who have been thinking about these issues from a range of different disciplines — and also getting lay input. I think it’s often been one or the other. One way we can get lay input in a way that makes a difference in terms of message content is to survey people about what sorts of things they would want to say. It’s important to see what the general themes are that people would want to say and then translate those [into a message that aliens might be able to interpret.]"

The Arecibo message

METI's messages won't be the first ones we've ever beamed into space. Back in 1974, astronomer Frank Drake used the Arecibo Observatory in Puerto Rico — at the time, the largest radio telescope in the world — to broadcast a long series of rhythmic pulses, 1,679 of them to be exact, with a clear, repetitive structure toward a star cluster called Messier 13, which sits over 25,000 light years from Earth.

Because that message, now known as the Arecibo message, travels at the speed of light, it won't reach its intended target for another 25,000 years. If there are any aliens living in Messier 13 who happen to have a SETI program of their own, or some equivalent program that listens constantly for alien radio messages, and who happen to have their listening devices pointed in the right direction at the right moment, then perhaps we can expect a call back in around 50,000 years.

In other words, the Arecibo message was not exactly sent to the ideal target. There are star systems we now know of with potentially habitable planets that are much, much closer. METI wants to target these. If there are aliens in our neighborhood, there's no reason we couldn't make contact within our own lifetimes.

But what if the aliens we contact end up being hostile? What if they take our message to be a dinner bell, or perhaps worse: a call to arms? Even if the risk of prompting an alien invasion is small, is it worth betting the survival of humanity on it?

It's a weighty question, but one that we seem destined to forgo answering. The lure of making contact is, for some, too profound a prospect not to take the chance on.

SpaceX founder Elon Musk has even added his voice to the list of METI critics, imploring a more political approach: "Intentionally signaling other civilizations in the Milky Way Galaxy," he argued in a statement, "raises concerns from all the people of Earth, about both the message and the consequences of contact. A worldwide scientific, political and humanitarian discussion must occur before any message is sent."

Come 2018, all of this is set to come to a head. If METI scientists get their way, resolution to the debate may not arrive until we find ourselves visited by alien starships. That would be a profound day indeed. But will those starships be diplomatic envoys, or will they be warships?