The question of where life began is a difficult one to answer. While many scientists believe that life began on earth, others believe that life, or at least its building blocks, first formed in space. A recent study from the University of Sherbrooke, in Canada, has shown how complex organic molecules could form on icy comets - from nothing more than simple molecules and radiation. And it's possible that this could explain how complex molecules like amino acids - which are the building blocks of proteins - could have originally formed billions of years ago and led to the beginning of life on... Like this podcast? Please help us by supporting the Naked Scientists