Phenomena that are not UFOs:

There is a whole series of phenomena, either natural or artificial which do not have any extraterrestrial visitors features about them. These phenomena are sometimes called upon rightly, or wrongly, as the cause of a UFO report, or the as cause of all UFO reports. Here is some information on these very terrestrial phenomena, including descriptions of their features. In connection with UFO reports, this enables you to check if a sighting can or cannot be explained by one of these commonplace causes.

Noctilucent clouds:

The phenomenon:

Noctilucent clouds are made up of ice and particles in the upper atmosphere that get visible at dawn or dusk because the sun's rays illuminate them, causing them to appear as strange luminous masses, with orange, pink or red hue.

Above: Simplified figure with exaggerated proportions of the cause of noctilucents clouds.

Pictures:

	Noctilucent clouds in a dark night.
	They are not always pinkish, they can have a bluish hue.
	Among the most intriguing, those are reflexions of the setting sun on a rocket's contrails. The display is more puzzling still when the sun's reflection illuminates the short lengthened cloud left by a plane that dropped propellant or cooling liquid.
	If there is only one cloud rather than a whole group like here, the phenomenon appears also stranger.
	This is not a noctilucent cloud.
	This is also not noctilucent clouds.

Noctilucent clouds and the UFO phenomenon:

They are, rather seldom, reported as possible UFOs by witnesses who know little about the sky and are puzzled by their weird appearance, but since they are only clouds, they are quickly identified as such by the experienced ufologists.

The immense majority of the reports of witnesses on noctilucent clouds that they did not readily identify are not at all of the type "I saw an alien spaceship", they are of the type "I saw a weird phenomenon, do you have an explanation?"

The sun plays a similar role on other ordinary objects of the sky, such as balloons.

Any ufologist with basic experience and common senses can recognize a noctilucent cloud report as such. It is obviously also true that there are ufologists without experience or too whimsical who cannot recognize this cause or do not want to recognize it, and that there are newspapermen who headline "UFO" such reports without giving or finding or asking for the cause.

It should be also obvious to any educated person, whatever their position regarding the UFO phenomenon, that it is not noctilucent clouds that generate the UFO sighting reports that are the worthiest of interest, and that noctilucent clouds do not haunt any serious catalog of the most puzzling UFO sightings.

Example of "UFO" report probably caused by a noctilucent cloud.

This page was last updated on May 8, 2006.