Could there be life on other planets? It turns out this is not an easy question to answer at all because, for starters, scientist still argue over the definition of the term 'life'. Since a complete discussion on which is the best way to define it would be way off-topic, we will use this widely accepted definition instead: "a condition that distinguishes organisms from inorganic objects and dead organisms, being manifested by growth through metabolism, reproduction, and the power of adaptation to environment through changes originating internally". We will also informally define 'intelligent life' as the condition in which a...