The former US President Ronald Reagan believed that aliens were planning an attack to conquer earth.
A new book claimed that the 40th President of the United States even asked Soviet premier Mikhail Gorbachev for Russian help to defeat the invasion, the Daily Star reported.
Sheffield-based author Dr David Clarke said that the former B-movie star was fascinated by films such as 'The Day The Earth Stood Still' and 'Close Encounters Of The Third Kind.