Scientists speculate about how hollow icy shells of apples ended up on Michigan trees
Michigan farmer Andrew Sietsema was out pruning his apple trees after an icy rain last winter when he noticed a bizarre phenomenon – what looked like little glass ornaments shaped exactly like apples.
Upon shaking the tree, he noticed more of them appeared. Upon closer examination, he realized shaking the tree would cause apple mush to “slip out of the bottom” of the icy casing surrounding.
“Most apples just fell off, ice and all. But quite a few would leave a cool ‘ghost apple’ behind,” Sietsema told Forbes Magazine.
Botanist James Wong told the magazine he’s not sure how an apple would rot and fall out of it’s frozen casing like that.
University of Illinois horticulturalist William Shoemaker suspected the ‘ghost apples’ were a result of the exceptionally cold weather caused by a polar vortex last February.
When the temperature drops to around around 0°F, their structure collapses, and a few could “spew their rotten contents successfully.”
But why weren’t the contents of the apple frozen along with their icy case?
Probably because their significant acid content keeps them from freezing, Shoemaker said.
Whatever the cause, the spooky apples made their way around social media again this Halloween. Now that we know to look for them, maybe farmers will spot a few more this winter.