In 1955 a young child, trying to reach Santa, dialed a misprinted phone number from a department store ad in the local newspaper.

Instead of calling Santa, the child called the unlisted number of the Continental Air Defense Command (Conad) Operations Center in Colorado.

Air Force Colonel Harry Shoup, the commander on duty that night who answered the child’s phone call, was quick to realise a mistake had been made – and assured the child he was Santa.

Every year since, Norad – Conad’s successor agency – has dutifully reported Santa’s location on 24 December to millions of children and their families.