GALLERY u PORTRAIT OF A BUSY SKY Soumyadeep Mukherjee Ice crystals in the atmosphere caused a double lunar halo to form over Kolkata, India, on September 25, 2021. Perseus peeks out from the Moon's light on the left, while a contrail slices through the right side of the smaller ring. DETAILS: Nikon D5600 camera and Tokina 11-to-16-mm zoom lens. Stack of 30 exposures, each 13 seconds long at f/3.2, ISO 160, and several 6-second exposures at f/4, ISO 800. q RIVER OF DUST Gregg Ruppel NGC 6559 in Sagittarius is a complex of reddish emission nebulae and smaller patches of bluish reflection nebulae. Meandering tendrils of dark gas and dust cut across its center like a braided river. DETAILS: Astrosysteme Austria ASA10N Newtonian astrograph and SBIG STL-11000M camera. Total exposure: 14 hours through Hα and LRGB filters. 76 AUGUST 2022 * SKY & TELESCOPE