I am fortunate to spend a bit of time in McCall in Pilgrim Cove. With the exception of one of my neighbors who does not understand the value of dark sky designation, it is very dark and quiet in the cove. I noticed a perfect ring around the moon on an evening walk with MMMa, the dog. I came back to the cabin and got Karen to see this phenomenon.
“Not that rare, I have seen that many times” said my spouse. Well, turns out she is correct, I just have to pay more attention. It does take certain atmospheric conditions – light is refracted through hexagonal ice crystals and it forms a 22 degree ring around the moon. This condition may exist as many as 100 days per year. As no light is refracted below 22 degrees the sky is darker inside the halo. I was happy to hear that bright spots sometimes seen on either side of the moon are known as Moon Dogs while the halo is called a Moon Ring or Winter Halo. Yes, this same phenomenon occurs around the sun under cirrus cloud conditions, those high wispy clouds contain water and hexagonal ice crystals. Who knew? Maybe everyone but me.
As I did my research on the moon I came across a Space.com article about “Elves” and “Blue jet” lightning. The International Space Station’s Atmosphere-Space Interactions Monitor caught a single Blue “jet”- upward lightning – from a thunderstorm over the Pacific Ocean along with four “elves” or optical and ultraviolet emissions from the bottom of the ionosphere. The jet reached 32 miles above sea level. This report was just issued this week and it is our first real look at elusive lightning phenomenon. Understanding the origins of lightning also could provide insight into how greenhouse gases are concentrated in Earth’s atmosphere. Following the upward jet, flashes of ultraviolet light appear as rapidly expanding concentric rings, these are dubbed “elves”. Dr. Hummel of the University of Texas at Austin commented on the importance of the knowledge that will be gained from this space observation. He also mentioned the elusive “jellyfish sprites” that dance in the sky during a thunderstorm. The sprites last only a millisecond but the image is amazing. Who knew?
Speaking of our planet – it is so encouraging to hear that we will belatedly focus on climate change in our country. We may have always had atmospheric phenomena but when we consider the unchecked impact of greenhouse gas on our environment, the “elves” may be the only safe beings. I appreciate and support the effort to “build it back better.”
Stay safe, wear a mask, social distance, and hand hygiene are still in order. Keep it together. Mike