Glory-ous days

Was heading back from Bangalore and the saw an amazing sight during take-off, shadow of the airplane on the cloud surrounded by colored rings. I thought it was first a circular rainbow caused by the airplane by some kind of a diffraction.

I came back home and later found out that its a totally different and more complicated phenemenon called Glory.

Glories are always directly opposite the sun, centered at the antisolar point and therefore below the horizon except at sunrise and sunset.

Look for them whenever mist or cloud is beneath you and the sun breaks through to shine on it.

Glories can be seen on mountains and hillsides, from aircraft and in sea fog and even indoors.

They are formed when light is scattered backwards by individual water droplets.

They have a bright centre but not nearly as bright as the corona's aureole. Their rings are delicately coloured like those of the corona's, blue on the inside changing through greens to red and purple outside. The ring intensities fall off much more slowly than those of the corona and sometimes three or even four rings are visible.

Shadows converge on the antisolar point and so glories are nearly always accompanied by your shadow or that of the aircraft you are in. When the shadow is grotesquely distorted by perspective it is called a "Brocken spectre".

- http://www.sundog.clara.co.uk/droplets/gloab.htm