Using the formula found in this article, you can use simple geometry to calculate the distance of contrails, such as the one made by this USAF B-52 over Columbus in 2011. Photo: Stephen Mosley Sr. – OPShots Contributor //
When you look up in the sky and you see a contrail, how far away is it? How far away are these contrails, a mile? two miles? Would you believe they are actually 20 to 100 miles away?
Contrails typically form above 30,000 feet, or around six to eight miles straight up. It’s quite hard to judge exactly how high it is, unless you know what type of plane it is. But assuming six miles is a pretty safe bet.
So if we assume it’s at least six miles above the ground, then all we need to do to find out how far away it is is to measure the angle of elevation. It’s quite a common child’s math problem, but usually applied the other way around, to measure the height of things if we know how far away they are.
via Contrail Science.
