A moonbow shines at left as the aurora borealis dances in the background. (Skye Commercial Photography)

The Isle of Skye, Scotland, is known for its rugged landscape and medieval castles. It’s also far enough north to be graced with the aurora borealis frequently throughout the winter months.

Remember, while the aurora borealis exists year-round, it is most noticeable and vibrant across the northern hemisphere during the winter months when nights are longer. The array of multicolored lights slithering across the sky is caused when solar particles from the sun (electrons and protons) interact with the gases in Earth’s atmosphere. Oxygen causes the bright greens you see, while nitrogen produces the stunning reds and purples.

While the dancing northern lights are certainly beautiful, for once they were not what initially caught my eye in this photo (and you all know how much I love the northern lights!). Instead, it was the glistening moonbow on the left side of the photo!

What is a moonbow, you ask? The process by which they form is very similar to a rainbow you see during the day. Light from the moon is reflected and refracted through liquid droplets in the atmosphere, producing the arcing moonbow you see in the photo.

However, there are some differences between moonbows and rainbows. Moonbows typically appear white and are much fainter than rainbows because the moon emits much less light than the sun. Less light emitted from the moon means less light that can be reflected through the liquid droplets, resulting in predominantly white light and far lower brightness. The fact that moonbows can be so faint is the reason they’re so rare. They may be there, just invisible to the naked eye.

So if there’s a pot of gold at the end of each rainbow, what’s at the end of each moonbow?

Weather is awesome. #cwgpicoftheweek

Thank you to Photography Skye for sharing their photo with us this week from Skye, Scotland.