Mike pointed out the plane with beautiful contrails; and then I pointed out that every time I see contrails, I wonder what causes them and why we only see them trailing behind some planes.
Right then and there while we sipped our coffee on the front porch, I picked up my iPhone, googled, and then read aloud that “contrails” really means “condensation trails.” They occur when water in jet exhaust mixes with wet, cold air. The water condenses and freezes into ice crystals. Without wet, cold air at the altitude at which the jet is flying, no contrails form. (A similar phenomenon occurs when we exhale on a cold day with moisture in the air — we see our breath!)
You answered something I've often wondered about - but I'd see them where I didn't have access to the internet (no handy phone) and would forget by the time I got home. Love the simplicity and focus of this.
