A Strange Phenomenon: Rainbow / Halo around airplane's shadow

[727Sky]

'A glory is an optical phenomenon that resembles an iconic saint's halo about the shadow of the observer's head,

caused by light of the Sun or (more rarely) the Moon interacting with the tiny water droplets that make up mist or clouds.

Yes I have seen the effect many times.. I always figured it was due to a thin layer of ice crystals present in high altitude clouds... Certain times of the year the effect is more prevalent but always a joy to see.