A collection of scientists and philosophers are planning to send messages into space in the hope that alien civilizations will find and hear them, and view the recent discovery of a planet around the nearest star to the Sun, Proxima b, as a good place to start.
Messaging Extraterrestrial Intelligence (METI), as the group is called, is starting a discussion about what the messages should say, with the intention to begin sending in 2018. However, many others remain deeply opposed to sending a message at all, raising the question of who has the right to speak for Earth.
In 1974, the Arecibo radio telescope sent a message to the globular star cluster M13. In 1977, the famous Golden Record was sent on the Voyager spacecraft for any alien to find it. These were, however, almost entirely symbolic gestures. The chance of aliens noticing a short and narrowly focused signal, or a tiny craft in the vastness of space was very low. Our unintentional signals are far more likely to give us away.
METI is planning a far more systematic approach. They have started fundraising to buy time on a powerful transmitter, or to build their own, to send extended signals with as much power as we can muster. They will be holding two conferences in 2017 to discuss what the message should contain and where it should be sent.
There are considerable obstacles to the presence of advanced life on Proxima b, but as the closest possibly inhabited world to our own, this is one place METI is considering directing a signal, Mercury News has reported. In the unlikely event of an advanced civilization there, it is also one place close enough for us to hold a conversation, albeit one with eight-year breaks between asking a question and getting an answer.
“The project will test the hypothesis that a powerful, intentional, information-rich signal from Earth may elicit a response from extraterrestrial intelligence, even if they already know of our existence from accidental leakage radiation,” METI's strategic plan states.
This worries some people; most prominently, Stephen Hawking, who has warned against the idea. In August, former Nature editor Mark Buchanan wrote in Nature Physics that it is dangerous for us to alert other civilizations, who are likely to be far more technically advanced than us, to our existence.
METI president Douglas A. Vakoch has responded in the same journal. “The risk we most often hear about – alien invasion – is simply not plausible,” he wrote. “Any civilization slightly more advanced than we are could already detect our presence through accidental electromagnetic radiation. Only a virtual twin of modern terrestrial technology would pick up information-rich beacons but be blind to the BBC at interstellar distances. If we are in danger of an alien invasion, it's too late.”
Vakoch argues that the risk of doing nothing may well be as high as sending a message. Unfortunately, as he acknowledges, the world lacks a good process of collective decision making as to who agrees. With the United Nations and other systems of global government failing to address these questions he argues to instead adopt peer review. “Decisions about allocating time for METI at publicly funded observatories should rely on the same procedure used for competing experiments,” he wrote.
Nevertheless, while METI has a fairly high-powered advisory board, critics of the idea will certainly question whether, just because they can get funding from one source, they should be able to do something with so much potential impact on the entire world.