Telescopes can tune in to alien TV
Public release date: 25-Oct-2006
Contact: Claire Bowles
New Scientist
"Radio telescopes designed to study the primordial universe could also eavesdrop on extraterrestrial civilisations similar to our own. 'By a happy accident,' says abraham Loeb of Harvard University, 'the telescopes will be sensitive to just the kind of radio emission that our civilisation is leaking into space.'
"The next generation of radio telescopes are designed to pick up radio waves emitted by neutral hydrogen molecules in the early universe. These signals originally had a wavelength of 21 centimetres, but the universe has expanded since they were emitted, stretching the waves in the process. Today, these signals have a wavelength of several metres,
corresponding to a frequency of tens or hundreds of megahertz. 'This overlaps with our civilisation's radio emissions, which are in the range 50 to 400 megahertz,' says Loeb."
http://www.eurekalert.org/pub_releases/2006-10/ns-tct102506.php

Bob Clark