This evening was fantastic. I was out on the back porch finishing up some laundry before I was going to go read for a bit and I realized that the moon was illuminating my back yard. I went out from the porch, looked up, and was greeted by on of the most glorious Moon Rings that I have seen in a really long time. Not only was there a perfect ring around the moon there was a slash right through it as well. What a great way to end my day. I have one more image to file away in my Rolodex.
The coolest part to ponder is that the moonlight is reflected sunlight. This reflected light is traveling an extra 238,855 x 2 miles to get here. Just think, while we are gazing up at the moon, the sun is lighting up the opposite side of the earth. The beams of sunlight have to travel past the earth and are bouncing back to us from the surface of the moon and yet it is still bright enough to light up my back yard. How cool it that!
(The 238,855 miles is the average distance from the earth to the moon over the course of its 27 plus day orbit around the earth.)
These rings are caused by the reflection of moonlight off of ice crystals in high, thin clouds. The ring has a radius of 22 degrees, which is set by the properties of water. Most often, the ring around the moon is caused by high, thin cirrus clouds -- sometimes too thin to be seen by any other means.
(I pulled this information off of some science/space orientated website. I copied and pasted it and now I can’t find the site again. I hope that I am correct in the information that I am passing on.)