Tag: Flagstaff Dark Sky

Aurora Borealis Visible from Northern Arizona

Aurora borealis on 23 April 2023 as seen from northern Arizona.
Aurora borealis on 23 April 2023 as seen from northern Arizona.

The aurora borealis that occurred Sunday night (23 April 2023) was an impressive event. The storm parameters* were all indicative of a major event so it was worth the effort to drive to a nearby dark (or at least reasonably dark) location and try to get some aurora photos.

Aurora borealis on 23 April 2023 as seen from northern Arizona.
Aurora borealis on 23 April 2023 as seen from northern Arizona.

I assumed that the aurora, if visible from northern Arizona, would be low on the northern horizon so I wanted a location without city lights to my north. The best location would have been the South Rim of Grand Canyon looking over the North Rim but clouds were plentiful in that region. So I headed south from Flagstaff and ended up on Anderson Mesa which has many good viewing locations.

Aurora borealis on 23 April 2023 as seen from northern Arizona.
Aurora borealis on 23 April 2023 as seen from northern Arizona.

Upon arrival I looked to the north but saw nothing with the unaided eye. A quick photo test, however, revealed that the aurora was in progress and visible through the clouds that were to the north. I took photos from about 2045 until 2330. The aurora was at its best from 2100 to 2145. It was much weaker and very faint after that time although still visible. At its peak, the auroral colors extended upwards 30–40 degrees in the sky!

Aurora borealis on 23 April 2023 as seen from northern Arizona.
Aurora borealis on 23 April 2023 as seen from northern Arizona.

I tried to see the aurora with the unaided eye but was never able to see it. I think that was because there was some light pollution from Flagstaff (yeah, it’s a Dark Sky city but it puts out more stray light with each passing year) and lights reflecting off the low clouds that were present to the north.

Time-lapse of aurora from 2053–2228 MST 23 April 2023.

But the camera had no difficulty capturing the subtle colors. I was shooting with a Nikon D750 and a Tamron 17–35mm wide angle lens set at 17mm, aperture was f/2.8, exposure was 15 seconds, and ISO 3200. I was using an intervalometer set to take a photo every minute. The camera was also set to do LENR (long exposure noise reduction) so that the actual time the camera was active was 30 seconds out of each minute. This gave me a chance to quickly review images after each shot was taken and that was useful. On the other hand, taking exposures without LENR and shooting, for example, every 15 seconds would have resulted in a much smoother time lapse. Good stuff to know for the next time we get an aurora event this far south!

*I was using SpaceweatherLive.com to monitor storm parameters.

Comet 46P/Wirtanen, Rocket Launches, and Fog

I went out to the Mormon Lake Overlook early last evening (12/08/2018) to photograph a couple of different events. First was the launch of the ULA Delta IV-Heavy NROL-71 mission from Vandenburg Air Force Base. After that, I planned on pointing the camera up towards Comet 46P/Wirtanen.

Comet 46P/Wirtanen.
Comet 46P/Wirtanen.

Only part of my plans worked out. The launch was scrubbed at T-7 seconds but I didn’t know about that until much later. I just kept shooting a series of 15-second exposures pointed towards the western horizon and hoping that I would capture it. No launch—and there was nothing to capture.

But, wait, not so fast! It turns out there was a shallow layer of fog in the Mormon Lake basin and the series of 15-second exposures over a period of about 10 minutes resulted in a nice time-lapse movie of the fog. Unfortunately, the camera was pointed at mostly sky with very little of the ground but I’m happy with the lucky result.

Time lapse showing undulations on the top of the fog layer.
Next, I shot a series of 60-second exposures of the comet. Although the skies were cloudless, there was a lot of moisture in the air. See the discussion above about fog! The presence of this moisture and very thin fog above resulted in very colorful stars. A nice effect.

Light pollution in the night sky.
Light pollution in the night sky.

For the third act, I pointed the camera back down and over the lake basin towards Flagstaff. The fog was dissipating at this time but still shows up well. What also shows up is the large amount of light pollution in Flagstaff. Flagstaff is the worlds First International Dark Sky City but it takes a lot of work to keep the skies dark. I fear we may be losing the battle.