By Jon Lomberg

On August 24 2009, a burst of radio energy punched through Earth’s atmosphere into space and began its journey to planet Gliese 581D, 20 light years away.

The Hello to Earth project captured the imagination of more than 25,000 people around the world, who composed messages for transmission. But not everyone is in favour of the quest to attract interstellar attention.

Gliese 581D is one of the closest exoplanets – newly discovered worlds outside the solar system. If there are intelligent organisms there, if they have radio receivers, if they are pointed in the right direction at the right time and if they are tuned to the right radio frequency, they will receive this mailbag of messages from Earth.

That’s a lot of “ifs”, which is precisely what makes the notion of SETI – The Search for Extraterrestrial Intelligence both appealing and difficult.

SETI has been conducted for more than 40 years by radio telescopes around the world. But it’s like looking for a needle in a whole field of haystacks. There are so many variables – which star, which radio frequency, how long to listen to each. It’s no wonder our SETI efforts have come up empty so far.

Now we place the problem squarely on the doorstep of Gliese 581D. Now they are the ones who must be looking our way, 20 years from now, at the right radio frequency. If there’s anybody there at all…

But what if everybody is listening and nobody is sending?

If we believe in ETs sending out radio beacons – much faster and cheaper than starships – then shouldn’t we hold up our end and transmit as well?

Actually we have. Several radio messages have been intentionally constructed and transmitted from Earth.

With the Hello From Earth project Australia joined the Galactic Club too, with its own homepage on the Galactic Internet. However, unless ETs have knowledge of English, they will have a hard time making much sense of it.

But I believe this project has little to do with communicating with ETs, who are unlikely to be looking our way at the right time. It is really a message to ourselves. The proverbial Man from Mars has always symbolised the Outsider, a person who can view our society from an unbiased perspective and see truths that escape us because we’re standing too close. Considering our message to ETs forces us to think about ourselves and our world in a very different way than we usually do.

We’re provided with a rare “cosmic perspective” where we can try to sum ourselves up, for good or ill, and give an account of ourselves to intelligence so remote (and possibly powerful) as to be viewed as a modern equivalent to God.

The messages on Hello From Earth are best seen as secular prayers, expressing our hopes, fears, our insouciance or humility.

25,880 messages were submitted during the Hello From Earth project, ranging from explanatory, elegant, poetic, and religious to esoteric, weird and charming. Reading the messages is a novel experience and, after all, it’s all basically a harmless exercise.

Or is it?

There has been a vigorous – and sometimes acrimonious- debate on this topic among SETI researchers. The classic stance is one articulated by Carl Sagan, which is that extremely advanced civilizations must have learned to live peacefully with sophisticated technology. Warlike civilisations would weed themselves out.

To survive your own technology and maintain your own planet, you need to be peaceful. If you are not peaceful your species destroys itself. If you are peaceful, your society might be around for a long time. We don’t know yet in which category to put humanity because our world-changing technology is only a few centuries old. But any ETs advanced enough to do us harm would be advanced ethically as well. So went the classic line of argument about the safety of interstellar transmissions.

Other students of the issue have been less confident. Maybe there is a reason we do not hear other signals.

Can we be sure that all powerful aliens are benevolent?

Studies of animal behavior in the only biosphere we know about show few examples of altruism. Why assume ETs are altruistic and interested in sharing their knowledge with us.

How could we ever know for sure? Science fiction – beginning with HG Wells’ ‘War of the Worlds’ in 1895 – has imagined a whole galaxy of nefarious aliens who want to subjugate, enslave, eat, or destroy us.

The Borg in Star Trek, for example, believe that by conquering and incorporating all races into their Collective, they are doing them a favor.

Maybe missionary zeal or weirder motives would encourage ETs to want to bring new worlds under their sway. If so, is it wise to call attention to us before knowing a little more about the neighborhood?

Opponents of transmitting have called for a moratorium on any transmissions until the debate has been waged on Earth and some consensus reached. Does anyone have a right to open the Earth to a threat, no matter how remote? The Apollo astronauts quarantined after their return from the Moon, guarding against the remote chance of them bring some lunar pathogen home.

Is the chance of attracting some Gliesian Ming the Merciless any less remote?

To date, the opponents of transmitting have been denied their day in court at any formal meeting of astronomers seeking to hammer out some policy on this. Until then, it is a free-for-all with many private organizations sending messages to join Earth’s already bright radio signature.

Let’s hope that if the ETs on Gliese 581D receive our messages and reply, they want nothing more than to come and sample some good Australian beer rather than some good Australians!

See Jon’s other guest postings for 10 days:

Astronomical art: Representing Planet Earth

My own private Star Trek

Behind the scenes: Contact, the movie

A message to Mars

Conceive of the vastness

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