Right now, radio telescopes are scanning the galaxy for a transmission from extraterrestrials. The seti Institute and other organizations around the world have been listening for roughly half a century. The Search for Extraterrestrial Intelligence (SETI) has become more important with the discovery of hundreds of new planets around distant stars. Somewhere out there, there could be another civilization.
The whole concept of seti relies on the idea that extraterrestrials are transmitting signals into the universe. Mostly, it’s assumed that these signals are deliberate attempts to communicate with other worlds. ET wants to talk to us. Or so we think. As with so many issues in SETI, there are plenty of questions and not enough answers.
We don’t know if extraterrestrials are willing or able to talk to us. But we’re even less sure about whether or not we should be talking to them. seti has no problem with listening in to the universe, and even potentially eavesdropping on transmissions that were never meant to reach us. However, the seti community is more divided on whether we should send our own messages, before or after we are contacted by extraterrestrials.
Messages have been beamed out to space in the past. There’s a famous digital pictogram sent out from the huge Arecibo radio telescope in 1974, which was aimed at the M13 globular star cluster. It will reach its target in around 25,000 years.
In recent times, someone has deliberately sent a message out into space roughly every two years. Some of these have been scientific outreach programs for young people. The most entertaining example came in 2008, when NASA transmitted the Beatles song “Across the Universe” into space using the huge dishes of its Deep Space Network!
Moving much slower than the speed of light, we have messages on spacecraft heading into interstellar space. Pioneers 10 and 11 carry stylised images of humans, a dna helix and information on our solar system. Voyagers 1 and 2 carry gold records with sounds and images of Earth. There’s a faint chance that at some point in the future, someone will find them.
It seems natural to assume that if we want to hear from extraterrestrials, we should be trying to talk to them ourselves. It hardly seems fair to expect them to do all the work. And if nobody talks, then how can anyone expect to hear from anyone else?
Nevertheless, sending messages into space is controversial. How do we decide what to say? And who should make the decision? So far, there has been no national or global coordination of these transmissions. Rules and codes of conduct have been drawn, and while they have been adopted by some major seti groups, they have no legal force.
Despite the lack of solid rules, a certain level of caution has still been practiced. All message projects have tried to avoid controversial subjects, focusing mainly on sending greetings, messages of goodwill and scientific data. Issues such as war and other negative subjects are avoided. Censorship is a controversial and contested subject when humans communicate amongst themselves.
Dr Morris Jones - Space Daily