There has been an active scientific search for signs of intelligent extraterrestrial life for more than 60 years but so far the effort to find an ET has turned up nothing.
A UK professor will deliver a talk in Sligo Institute of Technology tomorrow evening to describe this search and the likelihood of ever finding alien intelligence.
Prof Ian Morison is professor of astronomy at Gresham College in London and has spent more than four decades using radio telescopes to study the universe. His talk, "Are we alone? The Hunt for Extraterrestrial Intelligence", is a IT Sligo contribution to the ongoing Science Week Ireland.
Intelligent life is likely very rare, with our species probably the only sentient life in our entire galaxy, he said. Across the universe there is a real likelihood of intelligent life, but even the most optimistic astronomer would say no more than 1,000 planets might harbour it, he said.
If life like us is rare, simple life - single celled organisms and bacteria - is probably quite common, he added. We might not have to look further than Mars to find evidence of either extinct past simple life or even living organisms hidden under the surface.
Jupiter's moon Europa is also a possible place for simple life given recent discoveries confirming that it has a liquid water ocean. This would provide ideal conditions for the evolution of simple life.
He took part in a six year concerted effort to detect extraterrestrial intelligent life in the "Project Phoenix", but this intensive study of 820 distant star systems between 1998 and 2003 yielded nothing, Prof Morison said.
The reality was that we will probably never confirm the presence of extraterrestrials living in distant galaxies, because the distances are just too difficult to bridge.
"Somewhere out there an ET will exist, but the question is will we be close enough to find him?”
Prof Morison's talk talks place tomorrow evening at Sligo IT at 7.30pm.