DESCRIBED AS ONE of the most “spectacular light shows on earth” the talk of Moray on Friday was not, for once, the Aurora Borealis.
It was another spectacular natural lightshow that had people in the region reaching for their cameras – a wonderful double rainbow of a brightness and clarity very rarely seen.
A combination of weather conditions as the sun came up on Friday saw the spectrum of colours arching over the Covesea Lighthouse and other local landmarks. A local weather expert explained it to insideMoray, saying: “We had a beautiful start to the day when the sun came up over clear skies, providing more of the unusually warm weather we have seen already in November.
“That was matched by a very low and dark cloud front moving in from the north over the Moray Firth, and when the two met we had the Rainbows showing up perfectly against the dark skies.
“What most people never seem to notice is that when they are looking at rainbows they always have the sun at their backs – and the centre of the rainbow will always be directly opposite the direction of the sun.”
That is because rainbows are formed by drops of rain and were the human eye observes sunlight being reflected off each drop. Often, however, a double rainbow as widely seen in Moray is formed.
“Not all of the energy of the ray escapes the raindrop after it is reflected once,” a spokesman for the US National Centre for Atmospheric Research explains, adding: “A part of the ray is reflected again and travels along inside the drop to emerge from the drop.
“The rainbow we normally see is called the primary rainbow and is produced by one internal reflection – the secondary rainbow arises from two internal reflections and the rays exit the drop at an angle of 50 degrees rather than the 42 degrees for the red primary bow.
“Blue light emerges at an even larger angle of 53 degrees, and this effect produces a secondary rainbow that has its colours reversed compared to the primary rainbow.”
There you have it then – but for most people viewing the spectacular lightshow on Friday it was, well, simply amazing.
We have gathered a collection of the Rainbow images submitted by readers – they can all be seen on the insideMoray Facebook page.