After a string of incredibly cold days with dangerous temperatures and windchills, today marked the first day of what felt like a "summer-like" temperature: 27 degrees.
After -40+ below zero windchills, 27 feels very warm. Warm enough to be outside in only a t-shirt, sweatshirt, one layer of pants, one layer or socks, and boots. No hat...mittens...or face protector.
At any rate, the sky was a beautiful blue today and there was an interesting cloud formation that criss-crossed itself.
There's a faint circular shape of rainbow colors near the intersection of the contrails.
It's on the contrail that is leading to the upper right of the photo.
According to Wikipedia, "Their formation is most often triggered by the water vapor in the exhaust of aircraft engines, but can also be triggered by the changes in air pressure in wingtip vortices or in the air over the entire wing surface. Like all clouds, contrails are made of water, in the form of a suspension of billions of liquid droplets or ice crystals.
"Depending on the temperature and humidity at the altitude the contrail forms, they may be visible for only a few seconds or minutes, or may persist for hours and spread to be several miles wide. The resulting cloud forms may resemble cirrus, cirrocumulus, or cirrostratus. Persistent spreading contrails are thought to have a significant effect on global climate."
In the case of the picture I took, the contrails were visible for less than five minutes before they slowly dissipated and completely disappeared from the sky.