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A typical galaxy like the Milky Way contains as many stars as there are grains of sand on all the worlds beaches. Most of these stars have planetary systems and many will have the right conditions for life to flourish. LOFAR can potentially search for artificial radio signals from intelligent civilisations in nearby stellar systems. Credit: Femke Boekhorst/LOFAR |
Perhaps ET is just a solar system away, and perhaps all we need is one more telescope to find him. That's the hope, at least, of some scientists who say a new radio observatory being built in Europe may hold a chance of finding alien life beyond our planet.
The Low Frequency Array, or LOFAR, is a network of up to 25,000 small antennae being built in the Netherlands, Germany, Sweden, France and the United Kingdom. The distributed radio arrays will collectively scan the universe in the low radio frequency of light when they are completed in 2009.
"LOFAR can extend the search for extraterrestrial intelligence to an entirely unexplored part of the low-frequency radio spectrum, an area that is heavily used for civil and military communications here on Earth," said Michael Garrett, general director of ASTRON, the Netherlands Institute for Radio Astronomy and professor of radio techniques in astronomy at Leiden University in the Netherlands. "In addition, LOFAR can survey large areas of the sky simultaneously ? an important advantage if SETI signals are rare or transient in nature."
So far, the world?s most famous alien-hunting telescope, the Arecibo Observatory in Puerto Rico, has been unsuccessful in locating extraterrestrials. The giant dish, which has been listening for radio waves since 1963, may even have to shut down in a few years if it can?t recover the funding lost since the National Science Foundation decided to reduce its budget. LOFAR will scan a lower-frequency range of the electromagnetic spectrum than Arecibo ? the very range in which we Earthlings broadcast television and radio signals. Some scientists hope that LOFAR offers the chance to tune in to an alien version of ?I Love Lucy.?
But others are skeptical of this suggestion.
LOFAR will probably not be sensitive enough to detect ET?s TV, unless the aliens are broadcasting with much more powerful television transmitters than we have, said Seth Shostak, a senior astronomer at the SETI Institute in California. He calculated that an alien version of LOFAR would have to be at a distance of less than one light-year away from Earth to detect our television signals, which is closer than the closest star.
Furthermore, broadcasting TV out into space is already becoming pass? on Earth, where most of us get our signal through a cable in the wall, not rabbit ears on top of the set. Soon, we may forego over-the-air broadcasting altogether.
?Presumably, ET has done all that, and to think that ET television will still be broadcast into space the way we do, I think is being a bit na?ve,? Shostak told SPACE.com. ?The chances that they?re at the same level as us are very, very small.?
Still, to those who spend their time hunting and hoping for ET to finally phone home, any new tool that might aid the quest is welcome, such as SETI@home, which allows people to donate their personal computers? down time to the search.
?SETI searches are still only scratching the surface; we need to use as many different telescopes, techniques and strategies as possible, in order to maximize our chances of success,? said Dan Werthimer, SETI@home project scientist at the University of California, Berkeley.
