Ice Rings Around the Moon and Jupiter
About three weeks ago I was surfing facebook as I usually do late at night when a friend posted about a “ring around the moon”. A quick trip outside and I quickly found out what they were talking about.
It looks like I just had a glare in my lens, but it wasn’t. See below for an explanation. The 1st photo is a closeup with jupiter at about 1:00 in the upper right corner.
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There’s an old weather saying: ring around the moon means rain soon. There’s truth to this saying, because high cirrus clouds often come before a storm. Notice in these photos that the sky looks fairly clear. After all, you can see the sun or moon. And yet halos are a sign of high thin cirrus clouds drifting 20,000 feet or more above our heads.
These clouds contain millions of tiny ice crystals. The halos you see are caused by bothrefraction, or splitting of light, and also by reflection, or glints of light from these ice crystals. The crystals have to be oriented and positioned just so with respect to your eye, in order for the halo to appear.
So there you go. Courtesy of earthsky.org, an explanation of what causes the rings. Very cool. I will have to look UP more often!