Odds of finding ET is ‘1 in 10 million’

MELBOURNE - There is 1 in 10 million chance of successfully eavesdropping on the daily radio traffic of extraterrestrial life forms, calculated a pair of UK scientists.

Duncan Forgan, from the University of Edinburgh and Professor Bob Nichol from the Institute of Cosmology and Gravitation, used a computer modelling technique, called Monte Carlo Realisation, to simulate the growth and evolution of intelligent life in our galaxy.

They combined this with previous research showing the next-generation Square Kilometre Array (SKA) telescope will be able to pick up radio traffic from ET up to distances of 300 light years from Earth.

They calculated that the probability of picking up such transmissions as being extremely low - 1 in 10 million, to be precise.

The researchers assume that ET will only “leak” radio signals for about 100 years of its civilisation.

In their opinion, humans have been leaking signals from TV and military radar for that length of time, but are now becoming “radio quiet” as signals move to lower power.

However, Australian radio astronomer Dr Ray Norris of the Australia Telescope National Facility in Sydney is not so sure with these conclusions.

On the other hand SETI researcher Dr Ian Morrison of the Australian Centre for Astrobiology in Sydney welcomes the new research.

“It’s a good attempt to put some numbers showing the difficulties of using the eavesdropping approach to SETI,” ABC Science quoted Morrison as saying.

He said that the authors’ assumptions about how long ET will be radio loud for may not be defensible, but ultimately this is a minor issue, given the low levels of probability of making contact.

He said SETI would have a much better chance of detecting ET if it scanned all the stars in the galaxy for powerful signals - or “beacons” - sent out to deliberately contact other life forms.

In his opinion, the highest chance of a transmission would come from the centre of the galaxy, where most stars are, and a deliberately created beacon could be powerful enough to reach Earth from the far side of the galaxy.

“I think this paper helps explain why concentrating on beacons is preferable to concentrating on the eavesdropping approach,” said Morrison.

The calculation is presented in a paper accepted for publication in the International Journal of Astrobiology. (ANI)