Lunar 22 Degree Halo


The 22 degree halo is probably better known as the 'large halo round the moon'. Lunar haloes are much safer than solar ones because there is no risk of accidentally looking at the sun. They are noticed more often simply because of the lack of glare. Whether or not stars will be seen depends on how thick the cirrus is.

On this occasion only one star was bright enough to show through.

A delicate 22 degree halo round an almost full moon.

This image brings out the colour in the upper tangent arc part of the halo, most of the circular 22 degree halo was much weaker. Although the lunar halo was quite obvious it appeared almost colourless to the eye.

The 20 second exposure shows stars below the naked eye limit. Part of Leo is visible to the upper left of the moon and the cluster of stars at middle left is Coma Berenices. A faint satellite trail passes through the stars in the Plough at the top.


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