just now i was in the bathroom; i looked out the window to the south to see a clear, blue sky and a jet with a long vapor trail. it was nice, framed in the window, i could see it pulsing forward, as the jet was so far away the progress looked intermittent, not continuous, like it was moving and then not moving and repeating that.
the plane, and its contrail then disappeared and i stepped into the tub to press myself against the glass and stared hard. gone. no trace. i viewed as much of the sky as possible through the window and the sky was an empty blue. if it has still been there i could have watched it for a while.
it disappeared. there were no nearby nor distant clouds to hide the illuminating sunlight, it was there for less than a minute as it went from one window pane to another in a straight trajectory, creating a long contrail that maintained its own length until it all disappeared in an instant. there/not there. if it had continued, i would have easily seen it in the clear blue sky.