Image copyright Science Photo Library Image caption Radio telescopes have been listening for alien life for more than 30 years, so far without success

A network of UK researchers has decided to compose a message to aliens - but they are divided over whether such a message should be sent into space.

The group will enter the Breakthrough Message contest, which offers a $1m prize for creating a digital missive that represents human civilisation.

That prize accompanies a new effort to accelerate the search for extra-terrestrial intelligence (Seti).

Experts have argued for decades about the wisdom of broadcasting into space.

Listening out for aliens is one thing, but trying to contact them raises myriad concerns about what happens when civilisations collide.

The diversity of views was obvious at a conference of the UK Seti Research Network (UKSRN) in Leeds, where the group's 20 members were split down the middle in an informal vote.

It's a really interesting question: how do you construct a message that an alien intelligence could receive? Dr Anders Sandberg, University of Oxford

"We did a show of hands and we were perfectly evenly split," said Dr Anders Sandberg, speaking to journalists at the British Science Festival in Bradford.

Dr Sandberg, a philosopher from the Future of Humanity Institute at the University of Oxford, found himself voting twice.

"I'm a typical philosophy department guy. I raised my hand in both cases and they were all laughing at me."

But the group settled firmly in favour of composing a message, even if it might never leave the planet.

"What we could agree on was that it was worthwhile and important to try to devise that message, so that we can reach the best possible version," Dr Sandberg said.

He and three other UKSRN members have formed a working group to "thrash out the basics" of how their message might be composed and what it might contain.

For example, they might draft two suggestions: one using pictures, and one using more abstract content such as language or mathematics.

Other than its $1m (£0.65m) spoils, the details of the Breakthrough Message prize, funded by tech billionaire Yuri Milner, are yet to be announced. But the competition is open to anyone.

"There's a fair chance that we'll get beaten by a schoolgirl somewhere, and in that case more power to her!" Dr Sandberg said.

Image copyright Getty Images Image caption In July, Prof Stephen Hawking helped launch Breakthrough Initiatives' investment in Seti

If the British team's bid is successful, Dr Sandberg said they would plough the prize money back into Seti research, which has historically struggled for funding and credibility in the UK.

"We would use it to build up a slightly bigger Seti research community in the UK, because this has never really been funded. The giggle factor is pretty high."

Intergalactic advice?

Whoever wins the prize, Breakthrough Initiatives have pledged not to transmit the message until a "wide-ranging debate" about the risks and rewards has taken place.

"It seems a bit silly in a sense, this prize for a message that they promise not to send," Dr Sandberg said. "But on the other hand, from a scientific perspective, it's a really interesting question: how do you construct a message that an alien intelligence could receive?"

Dr Jill Stuart, who studies space law and policy at the London School of Economics, is not a member of the UKSRN but welcomed the group's decision to draft an interstellar introduction. She strongly supports the notion of announcing humanity's presence in the cosmos.

"I'm very explicitly in favour," Dr Stuart said, "not only because I think it's worth trying to contact them, but because of what I think it makes us do - reflecting back on ourselves, building a potential regime for how we could communicate, and so on."

But many researchers are much more wary about hitting "send", for various reasons - and these are arguments Dr Sandberg has heard many times.

"The most naive one would be that aliens will come and eat us or invade us," he said. "That is probably not very likely. But a more sophisticated version is that we have seen what happens when more advanced civilisations encounter less advanced ones."

On the other hand, we might learn something important.

"We have a lot of these uncertainties, but we also know that our own civilisation is in a fair bit of trouble. We face some pretty big threats.

"That means it might be a good idea to gamble, and hope there is someone slightly older and wiser out there. If aliens told us something about how to handle our climate, or artificial intelligence, we might want to listen."

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