sciencetech-blog

comments

A recent newspaper story about the discovery of a huge Earth-like planet 560 light-years away was headlined: 'New planet brings hope of life in space.'

A few years ago, that sort of claim would just have been laughed off. But this has changed in recent times: indeed, only a few days ago, a leading astronomer made a quite staggering claim.

We liked him but he went home: What if real aliens are not as cuddly as ET?

'It is not hyperbolic to suggest that scientists could very well discover extra-terrestrial intelligence within two  decades' time or less.' 

And this was no deluded alien bug-hunter.

This was Seth Shostak, senior astronomer at the SETI Institute in California, addressing the U.S. Congress. 

SETI stands for the Search for Extra-Terrestrial Intelligence. It was co-founded by astronomer and author Carl Sagan, and two Nobel prize-winners have worked there.

Dr Shostak was able to make such a prediction thanks to the immense power of the dazzling new weapons in SETI's armoury, such as the Hubble Space Telescope and the Kepler Space Observatory. 

Nasa's Kepler telescope has discovered 962 exoplanets (planets outside our solar system, which don't necessarily resemble Earth) in 72 star systems.

They include Kepler-10c, 17 times the weight of Earth, which made those headlines this month.

The Kepler telescope has a further 2,900 possible detections, as yet unconfirmed. And it's only been operating since 2009.

This implies there is an astounding number of Earth-type planets (with properties  scientists deem necessary for life, such as proximity to an energy source) out there. 

Kepler's discoveries mean there may be 40 billion other 'Earths' in our galaxy alone. Given such numbers, the probability of alien life has increased enormously.

Much extra-terrestrial life might not seem that exciting. For vast aeons of Earth prehistory, 'life' meant bacteria, amoeba and algae. So it would  probably be with most of those exoplanets.

What if they mean us ill like Mysteron agent Captain Black? Captain Scarlet's nemesis was taken over after Spectrum attacked the Mysteron settlement on Mars by mistake

But just supposing one or two of them had given rise to more complex life forms, capable of intelligence, of innovation. With 40 billion planets out there, the odds are that this will have happened.

Hence the chosen name of SETI. They are not searching just for alien life, but for alien intelligence — life forms that could communicate with us.

SETI not only looks for planets that could be Earthlike and habitable, it listens out for things like radio waves, produced only by advanced technological civilisations. Like ours. 

Aye, there's the rub. It's one thing to listen out for signals from the cosmos that might tell us They're Out There.

But we are also sending out radio signals of our own, and have been for the past 100 years. One of the first public radio broadcasts was from the Metropolitan Opera House in 1910: Cavalleria Rusticana.

Such broadcasts weren't necessarily received only by the handful who owned a wireless set. They also started to travel outwards from the Earth, like ripples from a stone thrown into a pond — but moving at the speed of light.
They are now more than 100 light years away — one light year is approximately 5,878,499,810,000 miles — and SETI reckons the nearest inhabited planet is just 12 light years away.

And they will go on travelling through the vast reaches of space for ever.

The BBC's first broadcast was in 1922, and we have been inadvertently shouting out at the cosmos since, advertising our presence.

Radio and television broadcasts, mobile phone calls, radar systems, their chatter and babble streaming away at the speed of light, and all saying one simple thing to any listeners with the technology to hear: HELLO!

Deep Space: It looks pretty but who knows what horrors lay in wait for us in the cosmos

With blithe and sunny optimism, many scientists from projects like SETI seem to believe any ETs out there who pick up our signals and come to visit will be something like the cuddly chap in the Steven Spielberg film.

The optimists have even begun another programme called Active SETI, or METI — Messaging to Extra-terrestrial Intelligences.

This means not just listening, but deliberately shouting out at top volume, explaining who we are and where in the galaxy we live.

Not all scientists are sanguine about this, however. One has even called it 'insanely risky, given the dearth of information we have about the nature of Extra-terrestrial Intelligence'.

John Billingham, a senior figure at SETI and Nasa, even called for a global moratorium on such programmes because of the potential risk to humanity's future.

Is this paranoia? Hardly, if you remember the lessons of our history.

For when an advanced people meet a less technologically sophisticated people, the results for the latter are generally catastrophic.

Look at the American Indians, or even worse, the Tasmanian aborigines, who were obliterated after the arrival of European settlers in the early 1800s.

The worst-case scenario of an alien attack on Earth is a staple of science fiction from H.G. Wells's War Of The Worlds to Tom Cruise's latest blockbuster, Edge Of Tomorrow.

We have no idea how super-intelligent aliens might regard us, but what if they see us as we do cows: a useful source of protein?

Or as mosquitoes: pests infesting a lovely and habitable planet, and best got rid of?

Arthur C. Clarke, the author of 2001: A Space Odyssey, predicted in 1974 that in 30 years' time we would sit at home on personal computers, doing our shopping

These might sound fanciful, but science fiction writers spend their lives engaged in imagining the future, and often turn out to be startlingly prescient.

The word 'cyberspace' was coined by sci-fi writers.

And Arthur C. Clarke, the author of 2001: A Space Odyssey, predicted in 1974 that in 30 years' time we would sit at home on personal computers, doing our shopping and buying our theatre tickets.

Even more frightening than the thought of space invaders is the risk of importing a devastating computer virus in an incoming signal from some advanced civilisation.

A leading Serbian astro-physicist, Professor Milan Cirkovic, has described how such viruses could 'download' themselves to Earth, and then damage our computer networks.

It is, he said: 'A very frightening thought.' So perhaps we should be keeping very, very quiet — instead of reaching out to seek for alien civilisations.

And if super-intelligent aliens don't get us, another extra-terrestrial will — a giant asteroid smashing into the Earth.

'The chances of this happening,' says Bill McGuire, professor of geophysical and climate hazards at University College, London, 'are 100 per cent.'

It's just a question of when.