In conjunction with Australia?s National Science week, that country?s Canberra Deep Space Communication Complex, with NASA?s cooperation, will send 160 character, Twitter-like messages into space. Their target is Gliese 581-d, an exoplanet (one that orbits other stars) in the constellation Libra about 20.3 light years away from Earth.

Planet Gliese 581-d, picture credit: ESO 2007
Planet Gliese 581-d, Picture credit: ESO 2007

The Gliese 581 planetary system has 4 known planets. The one designated as "d" is the most likely, according to recent determinations, to be habitable [even though the "581-c" is also high on the list]. While the planet is orbiting its red star every 66.8 days, Canberra will try to deliver messages from Earth.

"Can you hear me now?" Well, "Not quite yet" will be the response. Delivery isn?t being sent via UPS special two-day air. Instead, it will take about 20 years to arrive. Equivalent response time will turn youngsters into gray-haired retirees before they receive an acknowledgement.
The project isn?t so much about sending a message, but what message will be sent. The project’s spokesperson, Wilson da Silva, explains: "What’s interesting is not just whether there’s anyone listening, but what the public will say to intelligent life on another planet,"

As of this writing, 2,259 messages totaling 253,866 bytes had been recorded ? in English. You can see them or record your own message at Hello From Earth. Postings are hopeful, such as slightly altered John Lennon lyrics: "Imagine all the planets living life in peace." A few are fearful: "Please DONT nuke us…we’re NOT all that bad as a civilization." Then, there is the sensible and curious: "Hello extraterrestrial life. I hope they provide a dictionary with this. I am settling an argument, does all intelligent life reproduce sexually?" All combined, the messages could make a great sociological study of earthlings, regardless if 581-d ever receives, or understands, them.

Most evidence for exoplanets like 581-d is extrapolation from the minute wobble in a star caused by the gravity of an orbiting planet. However, in November, 2008, the Hubble space telescope got the first visible light images of a planet outside our solar system. It is orbiting the star Fomalhaut which is 25 light-years away in the constellation Piscis Austrinus. Scientific investigation of the solar system is also carried out with unmanned automated spacecraft. The Deep Space Network (DSN) guides and controls them with two-way communications, bringing back images and scientific information. DSN uses steerable, high-gain, parabolic reflector antennas. Tracking facilities are located near Canberra, Australia, California’s Mojave Desert, and Madrid, Spain.

Measurements of Gliese 581-d?s orbit "place it firmly in a region where conditions would be right for liquid water, and thus life as we know it," astronomer Michel Mayor said. Estimates of how many habitable planets could exist emanate from an equation by Dr. Frank Drake, an astronomer and astrophysicist who co-organized the first SETI conference. He explains: "I listed all the factors one needed to know to predict the number of detectable civilizations in our galaxy. I recognized that if they were all multiplied together, one got an estimate of the number of detectable civilizations." His mind boggling equation is: N = R* x fp x ne x f1 x fi x fc x L. An article in Cosmos magazine explains the elements of his formula.

Dr. Frank Drake and Carl Sagan designed the aluminum plaque that ended on Pioneer
Dr. Frank Drake and Carl Sagan designed Pioneer’s aluminum plaque, picture courtesy of NASA

Dr. Drake joined Carl Sagan in designing the gold anodized aluminum Pioneer plaque, the first physical message sent into space. They designed it to be understood by any extraterrestrials who came across it. The Canberra messages may not be as understandable to inhabitants on Gliese-d, because we are betting that Gliesians can communicate in English. Perhaps today?s grammar school children should be studying Gliesian instead of any Earth-based foreign language, just in case they get an answer from 581-d by the time they are ready to retire.

Regardless of the language you select, your message must be submitted to the Canberra project at Hello From Earth by 5pm Monday 24 August 2009 Sydney time (07:00 GMT Monday 24 August 2009).