Have you ever seen a moon halo? I was fortunate enough to witness this stunning phenomenon one winter and was completely taken aback by it.
This particular image was taken near Budapest. The Pleiades star cluster is visible to the right of the moon within the halo. Outside of the halo, to the left of the tree, you can also see Aldebaran (which is one of the brightest stars in the night sky). Finally, you should also recognize Orion’s belt, found above Aldebaran and to the left, near the halos edge.
A moon halo is created when the moon’s light is refracted off tiny, high altitude ice crystals – similar to the way a rainbow is created. The halo always has a radius of 22 degrees, making it appear 44 times larger than the full moon (which is half a degree). Because the moon isn’t as bright as the sun, moon halos are more colorless and tend to be bluer.
Of course, if the moon halo itself wasn’t cool enough, a lunar halo is personal – just like a rainbow. The halo you see is completely unique to you, your particular viewing angle, and the exact second-by-second viewing conditions. Have you ever seen a moon halo?