Disks & Holes ~ Chris Brown in the Shetland Isles, Scotland imaged this lunar halo on 24th February '10.  The Moon is in Gemini and Mars glows at 8 o' clock near the halo's inner rim. Olympus E620, ISO 800, 11-22mm ZD at 11mm, f/8 20s. ©Chris Brown,

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The moon shining in a dark sky can show us more halo details than the sun.  The “22-degree” halo is no such thing. It is a huge disk of light extending out to 50 degrees from the moon or sun.   We see the brighter inner parts of the disk here.   There is a hole in its middle where randomly oriented ice crystals cannot refract any light and this moonlit view shows it well.   The hole’s rim is lit with subtle reds and straw colours.   No strong rainbow hues with the 22-degree halo because its colours overlap.