Space telescope on the trail of ET

 

As US funding wanes, European scientists are taking the lead in the search for extra-terrestrial life. A network of interconnected radio telescopes is the latest advance – and a bid is in place to link Ireland to the grid, enabling us to take huge photos of the night sky, writes JOHN HOLDEN

These beliefs however are not backed up by credible, scientifically verifiable proof that aliens have visited here or that they actually exist at all.

For that you have to rely on the Search for Extra Terrestrial Intelligence (Seti) Institute in California. Since its foundation in 1984, it has searched for hard evidence of alien lifeforms, but so far has turned up a blank.

For the past five years the institute has been operating the world’s only radio telescope array that is purpose-built to detect potential radio signals from distant worlds. Finding radio, microwave or radar signals would provide significant evidence of intelligent life.

Seti has also become the umbrella term for any activity people engage in to search for evidence of extraterrestrial life. The Seti Institute in California was first established to consolidate this activity by taking a more structured and scientific approach.

Microsoft co-founder Paul Allen has donated around $30 million (€20.87m) to the project over the years, but US government spending cuts earlier this year have made it impossible to keep the search for ET alive.

Yet even as Seti activity in the US declines, interest is building across Europe thanks to the development of some “kick-ass” science and public interest in space exploration.

If there has ever been a time for Europeans to look for an ET it is now, given the discovery – so far – of more than 500 planets orbiting distant stars. This increases the odds of finding one with an environment with just right conditions for life, otherwise known as the Goldilocks Effect. European scientists now have the technology, and the appetite, for the challenge.

A traditional telescope captures visible light, light that you can see with the human eye. A radio telescope doesn’t capture light, it operates in the much lower radio frequency portion of the electromagnetic spectrum.

“Unlike a camera, you don’t get a picture from a radio telescope,” explains Dr Niall Smith of the Cork Institute of Technology and the Blackrock Castle Observatory in Cork.

“If a regular camera has 10 megapixels, then a radio telescope would only have one pixel. So you have to do a scan across the object several times in order to build up the image,” he says.

“The kinds of things you can see include hydrogen, which is all over the universe, as well as the sun, Jupiter, quasars, pulsars, exploding stars and remnants of exploding stars – anything that emits radio waves,” he adds. “When looking for ETI through radio astronomy, you look for the kinds of signals that we ourselves might produce,” explains Dr Anna Scaife of the Dublin Institute of Advanced Studies.

“Natural signals would look more broadband. You try to detect something like airport radar but from another planet. So we’re searching for signals that look man-made. The waves should look narrow and happen at particular wavelengths.”

A variety of radio telescopes around the world are used for Seti including the Arecibo Telescope in Puerto Rico. This type of technology has been around for decades but advances have been made in the types of radio frequencies and amount of sky that can be viewed all at once, an area where European scientists and engineers have been leading the way.

“Low Frequency Arrays (Lofar) are giant multipurpose sensor radio telescopes which can look at large portions of the sky all at once,” explains Trinity College astrophysicist and member of the Irish Lofar consortium, Dr Peter Gallagher.

There is now a network of interconnected Lofar stations throughout Europe, 36 of which are in the Netherlands, five in Germany, one each in France, the UK and Sweden. While independently useful to all participating countries, all Lofar antennae are also linked to a super computer. Every second Lofar antennae produce 10 terabytes of data – equivalent to 265 full DVDs.

“Lofar is ‘kick-ass’ science,” says Smith. “It’s different because of the new frequency ranges it can pick up. They look like mats on the ground that use software to pinpoint where the radiation is coming from. It’s much cheaper than building large telescopes like Arecibo and is producing better results.”

It is hoped that Ireland could join this Lofar group by establishing a node at Birr Castle, Co Offaly. It would take an investment of about €2.5 million and would be sited alongside the Great Telescope in Birr Castle Demesne, the largest telescope of its kind in the world when built in the 1840s.

The Irish Lofar group, which includes astronomers from universities and observatories, has applied to the Government for funding, and while the response was favourable, no money has been committed so far. The group is also meeting today with the Ireland Fund to apply for funding.

The Lofar network is already the largest telescope in the world at low radio frequencies. “By putting a station here we would have a radio telescope with a 1,400km diameter, says Gallagher. “This means we can take huge pictures of the night sky.”

That’s not all. The European astronomy drive is happening on two fronts. The Square Kilometre Array is a proposed €2 billion EU project involving similar but not identical technology to Lofar. It would be based either in South Africa or Australia. Combining all these signals from the different antennas will create a telescope with a collecting area the same as a dish with an area of one square kilometre.

A dish that big has the capacity to do all manner of interesting things. “If you build a telescope that good, you can do so much with it,” says Scaife.

For more go to: lofar.org, lofar.ie, seti.org, skatelescope.org

Say what? How would we speak to aliens?

IT IS one thing searching for extraterrestrials but what would we do if we found one? How would we manage to communicate?

Attempts at communication with extra terrestrials have been ongoing since the early 19th century. In the 1820s, mathematicians suggested communication from the Earth to life on the Moon might be made by clearing vast stretches of forest in Siberia and cutting out a huge diagram of the Pythagorean theorem, showing we had a basic grasp of mathematics.

Others proposed digging huge canals out of the Sahara Desert in the shape of a circle and then filling it with kerosene and setting it alight. Again this signal would suggest to ET that earthlings had an appreciation for geometry and pyrotechnics, proving our intelligence.

More recently, different techniques have been used at the Seti Institute in California and elsewhere. Unlike the 19th century, contact is now more frequently attempted by searching for transmissions from space rather than hoping a human message might be seen from above. This is also problematic though.

“For the past 20 years, radio astronomers have argued about where to look in the sky,” says Prof Michael Redfern of the School of Physics at NUI Galway. “There are a vast amount of frequencies to choose from but the Seti Institute decided to go with 1421 megahertz, because it is the most astro-physically important wavelength. It is also protected by law, so no other manmade radio activity can take place on that frequency.”

Even if a message from ET were miraculously intercepted, it’s improbable we’d be able to understand it considering we haven’t been able to translate a single non-human language from the animal kingdom. Seti researchers have even tried to understand animal linguistics, specifically dolphins.

When attempting active rather than passive communication, a Seti signal will have encoded information in it. “So it might repeat a series of prime numbers such as 2,3,5,7,11, etc,” says Niall Smith of the Blackrock Castle Observatory. Optical Seti is an alternative to radio astronomy and is used here in Ireland. “Were running a project at Blackrock Castle called optical Seti to communicate with civilisations that potentially use laser beams rather than radio waves to communicate,” says Smith.

Recently, scientist Doug Vakoch of the Seti Institute and composer Andrew Kaiser from Carnegie Mellon University in Pittsburgh wrote musical messages that might be sent into space to music-loving extraterrestrials.

Anyone who wants to communicate their own message into space can do so at the Earth Speaks Organisation website. People are invited to send pictures, sounds and text messages. See earthspeaks.seti.org