As wrong numbers go, the error that appeared in an American newspaper 60 years ago has touched the lives of more people than any other.
In a 1955 advertisement, the newspaper inadvertently listed the direct line of the crew commander at a US Air Force base in Colorado as the number children should call to reach Santa.
The hapless commander at the Continental Air Defence Command Operations Centre was besieged with calls, but, being a family man, he took it in good spirit and from the misprint, Santa Tracker was born.
The base is now known as the North American Aerospace Defense Command (NORAD) and on Christmas Eve millions of children around the world will log on to www.noradsanta.org to track the progress of Santa and his reindeer.
The website is already live and features lots of interactive pages, just in case children need any reason to fuel their excitement ahead of the big day.
Next Thursday, Santa Cams will stream live videos of Father Christmas making his magical journey to the home of all the world’s children, who can also find out his exact location on December 24 by emailing email@example.com
Weather-permitting, children in the UK may catch an early glimpse of ‘Santa’s sleigh’ around 5.20pm on Christmas Eve when the International Space Station (ISS), whose crew includes English astronaut Major Tim Peake, passes over the Britain.
The ISS is the largest man-made object in space and is bigger than a football pitch. It reflects the sun’s light as it passes overhead and so appears as a giant, star-like object moving across the night sky.
If the skies are cloudless, the space station will be visible for up to three minutes and can be tracked online using the free iPhone app here,
This year will see a full moon on Christmas Day for the first time since 1977, the year that Star Wars was launched on an expectant world. The full moon peaks at 11am on Christmas Day so should be fully visible as children young and old across the county begin unwrapping their presents from the wee small hours.