Moondogs caught by David Cartier ( caught by David Cartier ( images ) near midnight on December 26, '07 above Snag, Yukon Territory, Canada . The display, which includes parts of of a paraselenic (lunar parhelic) circle , 22 degree halo, lower pillar and submoon was created by diamond dust in the -40F air. Snag lies in a hollow formed by the White River and tributaries, a good location for diamond dust formation. Praktica VLC3 35mm Camera, 16mm Zenitar lens, 15 second exposure on Fuji Natura 1600 film. Image ©David Cartier, shown with permission.



The moon forms halos just like the sun. Its equivalent of sundogs are called paraselenae or parselenae. Lunar halos are intrinsiclly faint and to see them dark surroundings and a near full moon are best. Visually they often appear colourless or almost so because their light is not strong enough to excite the colour sensors in our eyes.







