Mock Mirage Lunar Flash

October 20, 2005

0507200017-18

Provided and copyright by: Laurent Laveder, Optics of the Atmosphere Gallery
Summary authors & editors: Laurent Laveder; Les Cowley

This photo pair was captured early in the evening on July 20, 2005 from Quimper, Bretagne, France and shows a classic mock mirage or M-Mir type of flash. When a temperature inversion layer in the atmosphere (generally a warm layer of air overriding a cooler layer) produces abnormal atmospheric refraction and thus a mirage, the top of the Moon appears to detach and flash green. This effect is almost always observed very near the horizon, but on the above photo, because vertical waves in the atmosphere acted in such a way to curve the inversion layer, the flash was visible well above the horizon (more than 1 degree).

Photo details: Camedia 5060 digital camera, a DCL-4337 eyepiece, mounted on a Megrez 80/480 refractor, 1/8 s,100 ASA.

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