Sometimes a luminous ring surrounds the sun. This atmospheric phenomenon is called a solar halo.
On Feb. 23rd, Mila Zinkova saw not one, but four wondrous circles around the sun in the sky of San Francisco. And that’s pretty rare! So what is going on here?
These are magnificent and rare displays of pyramidal crystal halos.
Ordinary halos are made by six-sided column- or plate-shaped crystals in high and cold cirrus clouds.
Over California their ends were capped with pyramids.
Yes, the air was filled with tiny pyramids of ice.
The pyramids always have fixed angles set by planes of atoms in the ice.
Light passing through them form ‘odd radius halos’ 9, 18, 20, 23, 24 and 35 degrees from the sun.
And here a video:
In the images, you can see a bright 9 degree ring, an 18 degree one and then a clump of twenty-something radius halos and finally at the outer edge the 35.