Aliens

Do Aliens Exist?And if they do - what would they look like? Where would they live? Would they be conscious beings? And what would happen if they found us?These are the biggest questions we''ve ever asked - and here, Professor Jim Al-Khalili, theoretical physicist and host of BBC Radio Four''s The Life Scientific, blasts off in search of answers. Coming with him are Martin Rees, Ian Stewart, Louisa...