One August day in 1841, near Lebanon, Tennessee, two enslaved people heard the sound of rain pattering on the tobacco leaves around them. But this was no ordinary rain: It was a deep red color. The sky, it seemed, was raining blood. Even more alarming, small pieces of flesh and fat seemed to be raining down, too. The two witnesses took the leaves inside to show their enslaver, Mr. E.M. Chandler, who quickly reported the event to his neighbors.

In an attempt to clear things up, pieces of fallen material were sent to Dr. Gerard Troost, a renowned scientist and collector of natural history specimens. Upon opening the package, Troost noted that it “had the offensive smell of putrid animal matter.” After a thorough analysis, Dr. Troost’s assessment was clear: “There is no doubt but that this substance is animal matter and belongs to our globe.”

The flesh and blood fall near Lebanon in 1841 was far from the only time blood rain or flesh has fallen from the sky, nor was it the last.…