On: Strange phenomenon in Norwegian sky

[pyre]

If it's direction of travel is away from the viewer while it is spiraling, then yes it would appear that way to the observer.

[yters → pyre]

Have you ever seen the contrails of rockets that have spiraled out? They're anything but nice and straight.

[pyre → yters]

Totally. It was definitely the 'greys.' Someone was drunk at the controls.