In case you hadn't heard, today is World UFO Day. Or it's at least one of several flying saucer holidays claiming to be the the biggest day of the year for out-of-this-world celebrations.

The shadowy group that's dubbed July 2 as World UFO Day has a website explaining what they say is the true meaning of the special day.

But check the history books and see that World UFO Day used to be celebrated on June 24 as well as July 2. The first date refers to the day in 1947 when private pilot Kenneth Arnold ushered in the modern era of flying saucers when he claimed to have seen nine high-speed pie plate-shaped objects flying in formation near Mount Rainier in Washington.

The second date, July 2, stems from the close proximity to the day in 1947 when something fell from the sky and crashed on a ranch outside of Roswell, N.M., sparking rumors that eventually grew into an urban legend claiming it was an alien spaceship and its crew. Nobody knows the exact date that the object crashed, but it's generally known to have happened in early July 1947.

In an effort "to eliminate any confusion," the World UFO Day Organization declared July 2 as its official day of celebration.

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