THE rare phenomenon of a lunar rainbow, or Moonbow, was spotted in the skies above Warrington last night.
Also known as a lunar rainbow, the rare optical phenomenon is caused when the light from the moon is refracted through water droplets in the air.
The ring around the Moon was seen over clear skies on Saturday evening across the country including Staffordshire, the West Midlands, Surrey, Berkshire, Dorset, Yorkshire and the Isle of Wight.
The phenomenon is caused by the refraction of moonlight from ice crystals in the upper atmosphere.
According to the Met Office, the halo can suggest rainfall might be approaching, stating the halo is caused by ice crystals formed in high clouds.
The Lunar rainbow lights up the skies above Appleton ©Gary Skentelbery
*A moonbow (also known as a moon rainbow or lunar rainbow) is a rainbow produced by moonlight rather than direct sunlight. Other than the difference in the light source, its formation is the same as for a solar rainbow: It is caused by the refraction of light in many water droplets, such as a rain shower or a waterfall, and is always positioned in the opposite part of the sky from the Moon relative to the observer.
Moonbows are much fainter than solar rainbows, due to the smaller amount of light reflected from the surface of the Moon. Because the light is usually too faint to excite the cone colour receptors in human eyes, it is difficult for the human eye to discern colours in a moonbow. As a result, a moonbow often appears to be white. However, the colours in a moonbow do appear in long-exposure photographs.
Moonbows have been mentioned at least since Aristotle’s Meteorology (circa 350 BC).
Moonbows are most easily viewed when the Moon is at or nearest to its brightest phase full moon. For moonbows to have the greatest prospect of appearing, the Moon must be low in the sky (at an elevation of less than 42 degrees, preferably lower) and must not be obscured by clouds. In addition, the night sky must be very dark.
* Wikipedia
