Plenty of movies are based on true stories. I'll bet you never thought "The Blob" was one of them. Well, it was.  Sort of.

In September of 1950, in Philadelphia, two cops saw something float down from the sky and land in an open field. They called two other officers, and the four of them went to check it out.

What they found was a lavender substance that had the consistency of SOAP SUDS and gave off some sort of mist. One of the cops reached down and touched it, but it dissolved on his hand, leaving a sticky, odorless residue.

The rest of it that remained on the ground dissolved within half an hour. The FBI was called, but there was nothing to investigate, since the substance had dissolved. They tried to pass it off to the Air Force, who wanted nothing to do with it.

After that the story kind of died, and to this day nobody knows if it really happened. But it had gotten around enough for Hollywood to hear about it and turn into a movie. "The Blob", released in 1958, was filmed in nearby Phoenixville, Pennsylvania.

Here's the original trailer for the movie..which starred "Steve McQueen and a cast of exciting young people!":

And here's the 'The Blob' by The Five Blobs. Would you believe that the song was written and recorded by Burt Bacharach? It was!

(You can read more about the "true" story behind "The Blob" here.)