This month, Naked Astronomy goes in search of the civilisations with which we might share this Universe. Andrew Siemion, Director of Berkeley SETI Research Center, joins Ben McAllister and Adam Murphy to discuss how likely it is that we are not alone, how we are probing the distant reaches of space for intelligent life, what might thwart us and what's been found so far... Like this podcast? Please help us by supporting the Naked Scientists