Listening in on ET

A new telescope designed to scan the sky for pulsed laser signals may soon be eavesdropping on ET as he tries to phone home.

If alien civilisations are beaming laser messages across the galaxy, The Planetary Society, based in the US, is about to increase the odds of finding them when it opens its new Optical SETI (search for extraterrestrial intelligence) Telescope in Harvard, Massachusetts early in 2002.

Designed to scan the sky for pulsed laser signals, the all-sky Optical SETI Survey will use a 1.8 meter diameter optical telescope dedicated to scanning for communication between extra terrestrials.

‘Using only ‘Earth 2001′ technology, we could now generate a beamed laser pulse that appears 5000 times brighter than our sun, as seen by a distant civilisation in the direction of its slender beam,’ said project leader Professor Paul Horowitz of Harvard University. ‘In other words, interstellar laser communication is altogether practicable.’

Once operational, the new optical SETI observatory will search for brief pulses of light, covering the entire northern sky once every 200 clear nights. Its camera will be fixed on a stripe of sky with an array of 1024 ultrafast detectors, seeking flashes of light as short as a billionth of a second.

Professor Horowitz has worked on SETI projects with The Planetary Society for nearly two decades now. These include BETA, a radio telescope search in Harvard, Massachusetts; META in Argentina; and a search for laser communication from 13,000 selected stars.

Searching for continuous-wave laser SETI signals was first suggested in 1961by Robert Schwartz and Nobel Prize winner Charles Townes. A few years later, Monte Ross showed the substantial benefits of very short laser pulses for interstellar communications.

In November 1990 scientists at the University of Arizona developed a ‘language’ for talking by radio to alien civilisations on distant planets, whilst NASA began to use a ‘super computer’ in May, 1988, to try and pick up signals from distant civilisations.