Moonset Mirage Imaged 10th Jan by Claudia Hinz (atmospheric optics) from 1838m high Mt Wendelstein in Germany.  ©Claudia Hinz, shown with permission.

A highly distorted almost full-moon sets over a cold snow-covered landscape. The inset taken minutes later shows it split into several layers. Miles of intervening atmosphere preferentially scatter away blue light leaving the normally silvery moon highly reddened.

Europe has experienced several continuous days of very cold weather with a persistent temperature inversion, cold air beneath warmer. "We had a very strong inversion, the mountain temperature was +2� with 4% humidity. In the valley measured at the same time -12�C and 80% humidity."

These are ideal conditions for sunset and moonset mirages. Moonlight is refracted in passing between the air layers of different temperature (and hence density). In some cases the resulting mirage has three images, the uppermost upright and two lower images, one upright and setting while the other is inverted and rising. Here the slices reveal layering in the inversion.

And later, the Earth's shadow and Belt of Venus.


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