“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.