June 10, 2008
This pair of remarkable moondogs, also known as paraselenae, the night time counterpart of sundogs, was observed from Snag Junction, Yukon Territory, Canada, on the night of December 28, 2007. When I took this shot, the temperature was about -40 F (coincidentally also -40 C), but the night was so gorgeous, I didn't even notice the cold. Paraselenae occur when moonlight filters through tiny prismatic ice crystals, also known as diamond dust, falling in the lower atmosphere. They’re often dramatically bright, when the Moon is near full, during periods of intense cold. Incidentally, Snag holds the record for the coldest temperature ever recorded on the North American continent; -85 F (-65 C), in February 1947.
Photo details: Praktica VLC3 35 mm SLR camera, 16 mm f/2.8 Zenitar lens, 15 second exposure, Fuji Natura 1600 film.