Google did nothing to end the speculation with a statement saying: "We consider the second 'o' critical to user recognition of our brand and pronunciation of our name. We are actively looking into the mysterious tweet that has appeared on the Google twitter stream and the disappearance of the 'o' on the Google home page. We hope to have an update in the coming weeks."
As there appeared to be no obvious event however, some thought it was a sign the Earth had made contact with aliens. Others suggested it was merely a publicity stunt for new sci-fi film District 9, and another said it was the anniversary of the Voyager I spacecraft.
The truth, however, was that it was marking the 20th anniversary of Japanese video game Zero Wing.
Google had later provided a clue on its Twitter page, posting: “1.12.12 25.15.21.18 15 1.18.5 2.5.12.15.14.7 20.15 21.19″.
When the numbers are replaced by the corresponding letters of the alphabet, it read "All your O are belong to us", a reference to Zero Wing's notoriously poor Japanese to English translation.
In the opening cut scene of the video game, a character says "All your base are belong to us".
The phrase was made popular by the Something Awful website, spreading through a flash animation with the slogan in it.
It became a viral internet hit between 2000 and 2002 and Google resurrected the classic example of "gamer humour" for Zero Wing's birthday.
