Sometimes,observers see this as a comet's tail, which can be visible to the unaided eye stretching across the night sky.

VOA: special.2011.02.09

"No!" he answered. His eye glasses became wet and he had to look over top of them to see the other man.

VOA: special.2010.03.20

Years later, Anderson described how she felt on that day: "There seemed to be people as far as the eye could see.

VOA: special.2009.01.25

Experts explain that the movement of air in the atmosphere and natural qualities of the human eye caused him to see markings that were not there.

VOA: special.2010.07.11