The daylight crescent Moon setting behind the WIYN observatory dome, the first teelscope completed at Kitt Peak National Observatory. Now there are over two dozen domes and radio telescopes on the mountain.

I had a great day visiting the observatory. The McMath-Pierce solar telescope was fascinating. It was great fun looking up the shaft at the objective. After the tour I put on an impromptu solar viewing for some of the guests. Later, the waning crescent Moon setting behind the WIYN 0.9 m dome caught my fancy.

Single shot ISO 100, f8, 50mm Sony a6300 taken 2017-05-20 19:08UT. Cropped and exposure adjustments in Photoshop.