[r9etb]

It was a flipping contrail from a commercial jet, folks. Just some peculiar anomaly of general aviation captured by happenstance photography.

Probably correct... but it's so much more fun the other way.

[The KG9 Kid]

I hate to spoil the fun of the “THEY’RE TERKING ER JERBS!” contingent on FR, but the speculation was getting way out of hand.