* The author is part of the community of readers of La Vanguardia
Last night there were some very interesting clouds in the sky, as we see in the Photos of the Readers of La Vanguardia. They are images captured from the home site, in Altet (Urgell). I don’t know what they were, maybe airplane contrails.
This could actually be an example of a twilight phenomenon, which occurs when missile or rocket propellant exhaust particles left in the vapor trail of a launch vehicle condense, freeze, and they then expand into the less dense upper atmosphere.
Suspended against a dark sky, the exhaust column is illuminated by high-altitude sunlight reflected through the scattering, producing a dramatic, colorful effect when viewed at ground level.
It can also be caused by contrails caused by airplanes. For example, in 2010, an airplane contrail in California led people to believe they had seen a missile launch.
This “twilight phenomenon” forms when unburned fuel and water particles condense, freeze, and then spread through the upper atmosphere, leaving a trail of icy droplets that diffracts sunlight and produces ribbons of colors such as pink, blue , green and orange.
The appearance and intensity of the phenomenon varies depending on the viewer’s location and weather conditions. Usually clear skies with no moonlight as cloud cover would block the view.
Previously, I was also able to capture, going home, this other series of images of the sunset in Vicfred, in La Segarra.
Finally, also from the house plot in Altet, I was able to photograph the moon late at night.
