Sometimes falling ice crystals make the atmosphere into a  giant lens causing arcs and halos to appear around the Sun or Moon.  This past Saturday night was just such a time near 
Madrid, 
Spain, where a winter sky displayed not only a bright Moon but as many as four rare lunar halos.   The brightest object, near the top of the 
above image, is the Moon.  Light from the Moon 
refracts through tumbling  hexagonal ice crystals into a 22 degree halo seen surrounding the Moon.  Elongating the 22 degree arc horizontally is a  
circumscribed halo caused by  
column ice crystals.  More rare, some moonlight refracts through more distant tumbling ice crystals to form a (third) rainbow-like arc 46 degrees from the Moon and 
appearing here  just above a picturesque winter landscape.  Furthermore, part of a whole  
46 degree circular halo  is also visible, so that an extremely rare -- especially for the Moon --  
 quadruple halo   was actually imaged.  The snow-capped trees in the foreground line the road 
Puerto de Navacerrada in the  
Sierra de Guadarrama mountain range near Madrid.  Far in the background is a famous winter skyscape that includes 
Sirius, the belt of Orion, and Betelgeuse all visible between the inner and outer arcs.  Halos and arcs typically last for minutes to hours,  so if you do see one there should be time to invite family, friends or neighbors to share your unusual lensed vista of the sky.