Shadow of Mt. Lemmon

Most of the time when I am at the Mount Lemmon SkyCenter I am showing guests the sunset as part of our nightly SkyNights program.  Last night I had gone up the mountain with my son Ian to do a little work and help out one of my colleagues.  Given that he was leading the program I was able to look to the east at sunset and observed the shadow of Mount Lemmon being projected on the inside of the Earth's atmosphere.  This phenomenon is observable from many high mountaintops, and last night the colors were particularly beautiful.  Ian took the image below just as we were heading off the mountain.  Notice the dark blue shadow just above the mountains in the distance.

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