Folks in Wonthaggi, Australia witnessed a rare sight on Monday. A “hole punch” cloud with a rainbow inside it. These clouds are also known as fallstreak hole clouds.
See the opening in the cloud pictured above? No, it wasn’t caused by a UFO. Or, HAARP. The hole is actually caused by falling frozen crystals.
Typically, water droplets attach themselves to particles in order to create ice crystals, or snow. This is what you see during a normal snowstorm.
In the case pictured above, these water droplets do not attach themselves to particles. Instead, they spontaneously form ice crystals when temperatures fall to -37 degrees celsius. When this occurs, it leads to a chain reaction causing water droplets around these crystals to evaporate. The crystals then fall below the cloud layer. That’s why you get the large hole in the cloud pictured above.
The rainbow is caused by the refraction of sunlight by the ice crystals.
Here’s what the same clouds look like from space. What’s the craziest cloud you’ve ever seen?