Lunar Halo Over Ústupky, Czech Republic

June 27, 2018


Photographer: Petr Horálek
Summary Authors: Petr Horálek; Jim Foster

The photo above showing an attention-getting lunar halo was snapped on March 3, 2018, over Ústupky, Czech Republic. I awoke in the middle of the night because bright moonlight (from the nearly full Moon) was streaming through the windows of my cottage home. The temperature was only about 18 F (-8 C), so I stepped out quickly to capture this shot.

Lunar halos like solar halos are found approximately 22 degrees from the lunar disk and are the result when moonlight is refracted by randomly-oriented, hexagonal ice crystals, either free-falling or in cirriform clouds. Paraselenae (moondogs) and their extended tails can be seen on either side of the halo. Note that Jupiter is the bright object at upper left. 

Photo Details: Canon 6D camera; Samyang 12 mm lens; f3.2; ISO 200; 13 second exposure; single shot.