Twilight phenomenon is produced when exhaust particles from missile or rocket propellant left in the vapor trail of a launch vehicle condense, freeze, and then expand in the less dense upper atmosphere.

The exhaust plume, which is suspended against a dark sky, is then illuminated by reflective high-altitude sunlight through dispersion, which produces a spectacular, colorful effect when seen at ground level.

The phenomenon typically occurs with launches that take place either 30 to 60 minutes before sunrise or after sunset when a booster rocket or missile rises out of the darkness and into a sunlit area, relative to an observer's perspective on the ground.

That belief stems from the appearance of the launch vehicle's contrail as it becomes twisted into knots by upper altitude air currents or wind shear.

On the rare occasions when a missile or rocket does malfunction, it is destroyed by a Range Safety Officer before reaching the altitudes where twilight phenomenon occur.