The effort was made to celebrate a major upgrade to the Arecibo Radio Telescope in Puerto Rico, using a megawatt transmitter. The message was aimed at the M13 globular cluster at the edge of the Milky Way Galaxy. It was of sufficient strength that it could be picked up by an equivalent of Arecibo anywhere in the Galaxy.
The SETI Signal
According to SETI (1):
“The message consists of 1679 bits, arranged into 73 lines of 23 characters per line (these are both prime numbers, and may help the aliens decode the message). The ‘ones’ and ‘zeroes’ were transmitted by frequency shifting at the rate of 10 bits per second. The total broadcast lasted less than three minutes. It consists, among other things, of the Arecibo telescope, our solar system, DNA, a stick figure of a human, and some of the biochemicals of earthly life.”
The scientists at Arecibo did not expect that aliens would ever respond. M13 is 21,000 light years from Earth, so in any case any reply from the star cluster would be received about the year 43974. The message was an intellectual exercise by Sagan, Drake, and company to figure out how one civilization might contact another across interstellar distances.
Of course, the fact that the scientists at Arecibo did not expect a response does not mean that one was not forthcoming. In 2001 (2) a crop circle suddenly appeared next to the Chilbolton Observatory in Hampshire, England. The crop circle was remarkably similar to the one sent into space 27 years before, consisting of a different solar system, an image of a presumed alien, nonhuman DNA, and a microwave antenna.
Crop Circles of Human Origin?
While some have speculated that crop circles, a world-wide phenomenon, are the work of aliens, the design that was found at Chilbolton was almost certainly of human origin, albeit people with a great deal of sophistication and research behind their effort.
For aliens to have responded to the Arecibo signal in such a way, they would have had to sneak onto the farm, made the crop circle, and then go away undetected. Not the most practical mode of communication.
Few if any other serious attempts have been made to contact aliens since the Arecibo effort. According to the UK Daily Mail (3), that may change in 2018 thanks to a group called METI (Messaging Extraterrestrial Intelligence) based in San Francisco.
METI would like to use a radio telescope like Arecibo to transmit a message containing math and physics concepts to nearby star systems where exo-planets have been detected. The idea is to announce the presence of Earth civilization to possible alien societies and to indicate that we are advanced enough to be worth communicating with.
Communicating with Aliens
The idea of proactively trying to communicate with aliens is somewhat controversial. Professor Stephen Hawking has warned that contact with an advanced alien civilization may not redound to Earth’s advantage. He cited the example of what happened to peoples living in the Americas when European explorers came into contact with them. Even if the aliens are not overtly hostile, culture shock might well prove to be damaging to Earth.
Douglas Vakoch, president of METI, has countered that it is too late for Earth to conceal itself as we have been broadcasting our presence to the universe since radio was invented at the beginning of the 20th century. That we have not been invaded yet suggests that any aliens have benign intentions.
On the other hand, the silence coming from the universe may mean that Earth is under some kind of Star Trek-style noninterference directive.