I failed to see the aurora las night despite a red alert, but the halo around the Moon was magnificent. Lots of people saw it. This is the 22 degree halo. This means an angle of 22 degrees is subtended from the centre of the Moon to the halo. The Moon itself subtends about half a degree. I was hoping to make some measurements on the photo to verify it but even allowing for blurring of the Moon due to the overexposure needed to pick up the halo, I can't see it would work by measuring. Cearcall mun Ghealaich is a poem by Catriona Montgomery set and sung by Julie Fowlis about the portents associated with a ring around the Moon.
