Most people who watch The Blob see it as a fun, campy fantasy—an inventive tall tale. Gelatinous aliens don’t actually fall to earth on meteors. They don’t eat and grow and eat and grow. They don’t devour mid-sized towns.
Unlikely as it seems, there’s some reason to believe that The Blob was based on a true story. In 1950, eight years before The Blob was released, two Philadelphia police officers named Joe Keenan and John Collins saw a big, bright flying saucer six feet in diameter fall out of the night sky. They chased it, and where it landed they found a one foot high mass of glittering “purple jelly.” The officers believed it was alive. In their report, they said that the jelly was pulsing and glowing, but that it weighed so little it didn’t even bend the grass it was resting on.
Two other cops arrived for backup, one of whom, Sergeant Joe Cook, actually picked up a handful of the substance. The guy who does that in The Blob suffers a horrible fate, obviously, and if you or I were there, we might well have told Sergeant Cook to leave the stuff alone, for pity’s sake, what are you doing, haven’t you ever seen a horror film? STOP!
As it happened, though, Joe Cook was fine. The jelly did not eat him. It cam apart in his hands, though tiny globules stuck to him. Those quickly evaporated, leaving behind an “odorless scum.” By the time the FBI arrived, according to an AP story at the time, “there was nothing to show FBI agents except a spot on the ground.”
Was there really a blobby flying saucer that touched down in Pennsylvania in 1950? Scientists are pretty skeptical; any liquid or semi-liquid substance on an asteroid would almost certainly burn off when the object entered the earth’s atmosphere.
Still, the Pentagon recently issued a report discussing what appear to be unidentified flying objects in American airspace. More, many eye-witnesses to meteorite landings have claimed to have found what the Welsh call pwdre ser, or “star rot” near the site of impact. Pwdre ser is a bad-smelling, jelly-like substance which evaporates quickly. It’s also been called “star jelly” and in French “crachet de lune”, or moonspit. Pwdre ser has been analyzed a couple of times. The most recent was following a meteorite landing in Scotland in 2009. Scientists found the space jelly it lacked DNA and didn’t seem to be either plant or animal. That’s what it wasn’t. They never figured out what it was.
So, there could be alien visitors to earth. And there could be alien purple jelly. Whether we’re likely to face a Blob apocalypse is another question.
It’s also not completely clear whether the Philadelphia incident inspired the 1958 movie The Blob directly. Producer Jack Harris never acknowledged the real-life pwdr eser as the origin of his own space slime. But Harris was from Pennsylvania, and so was his old friend Irvine Millgate, who is credited with the original idea for the Blob. Millgate could easily have remembered the local newspaper articles about the police dealing with the weird space substance. That’s probably how the Blob crawled out of the headlines and into horror legend.