Besides the Search for Extraterrestrial Intelligence (SETI) some scientists are working on a project called Messaging to Extraterrestrial Intelligence, which has the acronym of METI. The idea behind METI is to actively send information out into space with hopes that it will be received one day by an alien civilization.
To some extent, our civilization has inadvertently been engaging in METI since the 1950's or earlier. Our radio and television transmissions have been leaking out into interstellar space for more than 60 years. Since both radio and television signals travel at the speed of light, there has in theory been an expanding sphere of space that could have received our radio and television signals. Today the sphere has a diameter of about 120 light years, but in 10 years it will expand to a diameter of about 140 light years.
But some scientists question whether there is much chance that extraterrestrials could pick up our ordinary television or radio signals, because such signals undergo a weakening or attenuation the farther one gets from Earth. However, a high-intensity radio or television signal deliberately designed to be picked up by extraterrestrials would have a much higher chance of success.
Such a signal was sent on October 9, 2008 by the Message from Earth project. The message was beamed by a large radio telescope toward the nearby star Gliese 581. A planet about six times larger than Earth has been discovered revolving around this star, in the star's habitable zone. That means there's a chance this message might one day be picked up by intelligent beings if there is any intelligent life in that solar system. The message consisted of 501 smaller messages selected after a contest at a social networking site.
Now there is a new project called Lone Signal which is attempting to further “crowd source” the transmission of radio signals to extraterrestrials. Having unfettered access to a large radio telescope in South Africa, the Lone Signal project is apparently taking a much less exclusive approach than the Message from Earth project. Apparently any Tom, Dick, or Harry will be able to leverage this project to beam their Facebook updates to the nearby star Gliese 526, where extraterrestrials might be able to pick them up.
Question for thought: do you really need to be transmitting the details of your latest shopping trip not only to the entire planet Earth, but also to another planet?
MSN has a story on this development with the headline “You might be able to communicate with aliens next week.” That is not quite true. The Lone Signal project will begin transmitting to a star 17.6 light years away, which means that the earliest any alien civilization could get your Facebook updates is 17.6 years from now. Even if the ET culture were to reply immediately, we wouldn't get an answer for another 35.2 years.
Some thinkers say it is folly for mankind to be deliberately announcing our existence to extraterrestrial civilizations. The thinking is that by announcing our existence, we may spur the arrival of an alien invasion, and they might kill us all or enslave us.
An alien planet. Montage by M. Mahin.
I think there is little risk in projects such as the completed Message from Earth project and the upcoming Lone Signal project. My reasons are as follows:
- Presumably if an extraterrestrial civilization were advanced enough to be able to destroy us or enslave us, it would be at least thousands of years more advanced than us. But if such a civilization existed nearby, it would already have had abundant opportunities to come here and destroy us or enslave us. Since we have not yet been enslaved or destroyed, there presumably is not any super-advanced civilization nearby that is interested in doing that.
- We are at a risk of destroying ourselves through nuclear war or environmental degradation. If we were to be visited by extraterrestrials, they might prevent us from doing that, which would be a net gain. So it is not clear that the risk of announcing our existence outweighs the potential benefits. It would be quite a different situation if we had a stable civilization with no risk of extinction or collapse– then you might argue: why risk our safe, secure situation?
I think that if we do deliberately beam radio transmissions to other planets, we should be mainly sending the greatest works of human culture. Rather than the “cosmic narcissism” of sending social network updates, we should be sending the works of art, history, music, science, and literature we would most want to survive if man does not last beyond this century.