Icons of Arizona
June 22, 2022
Photographer: Thomas McGuire
Summary Author: Thomas McGuire
The images above combine two iconic symbols of Arizona, the stately saguaro cactus and “The Valley of the Sun,” as the greater Phoenix area is often called. Both photos were taken on March 18, 2022, at sunset as the full moon was rising.
Saguaro cacti are endemic to the Sonoran Desert and are the tallest cactus species native to North America –- some specimens are over 50 ft (15 m) in height. The word “saguaro” originated in an indigenous language spoken by peoples of the Sonoran Desert in what is now Mexico. It’s pronounced “sah WAH roh.”
Taking sunset or sunrise images with the moon in view is challenging. The images featured here required a confluence of conditions. My first task was finding a photogenic saguaro cactus on a clear eastern horizon. Then I consulted astronomical tables in an ephemeris to determine when the Moon would be fullest, as well as the precise time and geographic direction of sunset. An added timing and positioning consideration is that at this location the land rises to the east about 5° above a flat horizon. Of course, a little luck with clouds and stray light is also helpful. Note that the 2nd image was taken in diminishing light, so it shows significantly more noise (graininess and color error) than the top photo.