Lunar Lights Over New South Wales

July 12, 2016

 Lunararc_NSW_10-6-16-11 (2)

Photographer: Dee Hartin
Summary Authors: Dee Hartin; Jim Foster
Shown above is an unusual capture of a moondog, a partial 22 degree lunar halo and circumscribed halo as observed from Casino, New South Wales, Australia, on June 10, 2016. The Moon, at far left, was approaching first quarter and thus not particularly bright, but ice crystals in the patchy cloud near the halos were oriented in such a way to create both the halos and the colorful moondog, visible with the unaided eye but brought out by a long (20 second) exposure. Note that the advancing mid-level cloud deck at bottom and left is composed of minute, supercooled water droplets rather than ice crystals. It appears that this is a hole punch cloud -- caused by a passing airplane or jet. The ice crystals mentioned above formed when the water droplets instantly froze after being jostled by the aircraft. They're actually falling through the hole The bright object to the upper right of the Moon is Jupiter.
Photo Details: Camera Model: NIKON D5100; Lens: 18.0-55.0 mm f/3.5-5.6; Focal Length: 18mm (35mm equivalent: 27mm); Aperture: ƒ/4.5; Exposure Time: 25.000 s; ISO equiv: 1250; Software: Adobe Photoshop Lightroom 5.4 (Windows). Thanks to David Lynch for his insights about this topic and for the annotated photo.