Is there alien life on alien worlds? As we look out into the universe, we find more and more planets, but our search for extra-terrestrial life has so far yielded nothing. In this talk, Geraint Lewis will explore our scientific understanding of life in the universe, our continuing search for the signatures of alien civilisations, and address the question of "where is everybody?". We will find that, whilst life may be common, intelligent life and star-crossing civilisations appear to be vanishingly rare, and we might be alone in the universe.