On Christmas Eve, residents in Moscow, Russia, saw a strange sight in
the sky: a cloud shaped like a DNA double helix. Is it contrail
or a divine sign from the Flying Spaghetti Monster?
I've seen that but only from an aerobatic airplane with smoke generators on the wingtips. I can't think of any natural process that would cause that formation.
I can't think of any natural process that would cause that formation.