146031PD: The Flyers Cross or the Glory of the Pilot from an airplane window over Western Australia, 1961

Summary

The Flyers Cross also known as The Glory of the Pilot. "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. The glory consists of one or more concentric, successively dimmer rings, each of which is red on the outside and bluish towards the centre. The effect is believed to happen due to classical wave tunneling, when light nearby a droplet tunnels through air inside the droplet and, in the case of a glory, is emitted backwards due to resonance effects. Like a rainbow, a glory is centered on the antisolar (or, in case of the Moon, antilunar) point, which coincides with the shadow of the observer's head. Since this point is by definition diametrically opposed to the Sun's (or Moon's) position in the sky, it always lies below the observer's horizon when the Sun (Moon) is up. In order to see a glory, therefore, the clouds or fog causing it must be located below the observer, in a straight line with the Sun/Moon and the observer's eye. Hence, the glory is commonly observed from a high viewpoint such as a mountain, tall building or from an aircraft. In the latter case, if the plane is flying sufficiently low for its shadow to be visible on the clouds, the glory always surrounds it. This is sometimes called The Glory of the Pilot." (Wikipedia 2015)