If you could send a message into space, what would it say? "Greetings, fellow sentient beings"? "We come in peace"? "Hi, we've kind of messed up our planet and we wondered if by chance anyone out there had a spare one?"
The subject of alien life — and its presence or absence in the universe — has been moving up the agenda, thanks to the approaching anniversary of the day in April 1960 when Frank Drake, an astronomer at Cornell University, pointed a radio telescope towards Tau Ceti, a suitably Sun-like star. Drake was looking for radio transmissions that could indicate the presence of intelligent life. The search came up empty but it kick-started the SETI programme — the Search for Extraterrestrial Intelligence. Fifty years later, the SETI team is still looking and still puzzled by the Fermi paradox (Enrico Fermi, the atomic scientist): that the universe is large enough to harbour a host of civilisations, so why haven't they been in touch?
Points of view
Some have suggested that, while life may be abundant, intelligent life may be rare. Others think bursts of gamma rays periodically sterilise the stars, forcing the process to begin again or that any species dominating its planet will exhaust its resources long before it steps into space. Then there is the problem of detection: SETI has spent decades looking for radio signals but Earth's equivalent emissions are becoming harder to detect as we graduate to digital distribution.
Rather than waiting for ET to say hello, then, it may be better to grab his attention. Nasa's Pioneer and Voyager spacecraft carried metal plaques identifying their time and place of origin. The Voyager message, carried on a 12-inch, gold-plated copper disk, contained sounds and images "selected to portray the diversity of life and culture on Earth", including music, animal noises and spoken greetings in 55 languages. Given that it will take this message in a celestial bottle 40,000 years to reach another planetary system, it seems sensible to send radio signals — which is where you come in.
Ending the silence
To mark the SETI anniversary and the publication of Paul Davies's book The Eerie Silence, about our search for extraterrestrial life, Penguin UK and National Science and Engineering Week will send up to 5,000 messages into space via a radio telescope. The messages can be up to 40 words and can say anything — greetings, warnings, confessions, jokes. Among the entries already submitted is the following from Andy Hamilton, writer of the hit sitcom Outnumbered: "Attractive, fun-loving life form, blessed (and cursed) with a hungry mind, and wondering if it is alone in the universe, would like to meet other life forms with view to meaningful relationship. Must have good sense of humour." Quentin Cooper, the presenter of Radio 4's Material World, is responsible for the plea at the start of this piece for another planet to despoil, while Davies has opted for "10001001.00001001001101110011110001101000011101110100100011110010111101", an expression of the strength of interaction between matter and electromagnetic radiation, expressed in binary arithmetic. Comedian and QI panellist Alan Davies has a more pressing concern on his mind: "How do you address the issue of landfill on your planet, particularly with regard to disposable nappies?" May be we are firing these messages into an empty sky — that a better technique for hunting aliens would be to hunt for microbes here that may have come from Mars. Still, it's worth a shot, isn't it? Submit your message of no more than 40 words at www.penguin.co.uk/eeriesilence. Entries will be accepted until February 28, with the winners announced in March.
