Chuck Dugan of the National Optical Astronomy Observatory on Kitt Peak took this 6-second exposure of Comet Pan-STARRS Tuesday on Kitt Peak with a Canon EOS Rebel T2i on a tripod with a remote cable.

Chuck Dugan/NOAO/Kitt Peak

Gates Pass is getting crowded at sunset with crowds of comet watchers, trying to catch a glimpse of Pan-STARRS in the short window of time between the sun setting and the comet dropping beneath the western horizon.

Arizona State Geologist Lee Allison reported a good crowd Tuesday and a good view of the comet.

This, from his Arizona Geology blog:

"The popular turn out at the Pass was overflowing with other Tucsonans, most with binoculars, spotting scopes, or the real thing.   We had our spotting scope with us.  From our vantage the comet showed up almost directly below the crescent moon.   The tail was nicely defined and seemed to change color as dusk deepened, at one point looking somewhat green to me."

Up on Kitt Peak, Chuck Dugan grabbed the nice shot of Comet Pan-STARRS and crescent moon on Tuesday night.

The comet will remain visible this week, and will set a bit later each night, but it should also get fainter as it moves farther from the sun.