New Years winter storm

January 3, 2019

A very cold storm system moved across the southwestern states on the last day of 2018 bringing snow to both the usual locations but in the lower elevations and the desert as well.

I awoke before dawn on New Years Day and was greeted with clear skies and a crescent Moon with the planets Venus and Jupiter shining brightly in the eastern sky. I drove out towards Mormon Lake anticipating great—albeit very cold—conditions for some sunrise snow photographs. On the way to the lake I encountered low clouds and patchy fog and there was nothing to be seen upon my arrival. It was already too close to sunrise to head back north or west so my only option was to wait and hope.

Clouds and fog clear away shortly after sunrise to reveal the San Francisco Peaks.

I missed the sunrise but about 20 to 30 minutes later the clouds cleared and the San Francisco Peaks were amazing. Low clouds and fog remained around the base of the peaks.

As the sun rose higher the side-lit rime ice on the wild grasses (i.e., weeds) at the Mormon Lake Overlook began to glisten and glow.

Temperatures were hovering in the low single digits and I was cold after standing around for about an hour. Time for breakfast and hot coffee.

The next day we hiked into West Fork Oak Creek knowing that the trail would be snow packed and there would be a dozen water crossings on ice—hopefully solid enough to support us. After several days of below freezing high temperatures and near or sub-zero overnight temperatures we were hopeful for safe ice.

Natural ice sculptures in West Fork Oak Creek.

There are several locations where water drips down the cliffs even at these cold temperatures resulting in wonderful icicles and bizarre ice sculptures on the ground.

We hiked to the “end” of the trail where it enters a narrow, rock-walled section of canyon often called “The Subway.” This was our turnaround spot.

Sunlight reflected off canyon walls and then reflected again on the ice.

On the way up the canyon we had not run into any other hikers. What a treat!

Another look at Comet 46P/Wirtanen

December 28, 2018

Comet 46P/Wirtanen has already made its closest approach to both Earth and Sun and is now moving away. Yet it remains high in the sky making it an easy night-sky object if you are in a very dark location. It then appears as a full moon-sized smudge in the sky.

Comet 46P/Wirtanen. (Nikon D750; 200mm; f/4; ISO 1600; 120 seconds)

The full moon is now waning and rising later so that there are a few hours in which to observe the comet without the interference of moon light. We had one night without moon interference and without clouds so I took advantage.

Instead of taking multiple images and stacking I shot single images of 1, 2, and 3-minute exposure. Should have been easy. But there was a gusty wind blowing so that the camera and tripod was sometimes jostled resulting in streaky stars. And I had trouble focusing the telephoto lens I wanted to use (Nikon 70-300mm). Frustrated and cold, I grabbed my legacy zoom lens (Nikon 80-200mm AIS Manual Focus). This one is easy to focus on stars. Just rotate the focus ring all the way until it stops.

That’s the thing about some legacy manual focus lenses. They can be easier to focus than modern auto focus lenses in the dark so I keep several very old lenses around for that reason.

Meteors and Comets

December 17, 2018

The past few nights have been interesting. On the evening of December 13–14 was the peak of the Geminid meteor shower. This year the expected peak was around 100–120 meteors per hour and various meteor counts appear to confirm that number.

At the same time, Comet 46P/Wirtanen has been getting a lot of attention. On December 16 it made its closest approach to Earth—only 11.5 million km away. That’s about 30 lunar distances for reference.

From SpaceWeather.com: “Although the comet is very close to Earth, it is not very bright. 46P/Wirtanen is a relatively small comet and, thus, barely visible to the unaided eye despite its proximity. It is nevertheless an easy target for digital cameras. Even a short exposure reveals the comet’s spherical form and emerald green hue.”

During the late evening of December 13, I traveled to Wupatki National Monument because of its dark skies. I shot a sequence of photos—each of 30 seconds duration—of the night sky hoping to catch a few meteors. One bright meteor blazed across the sky and I was able to catch part of it before it moved out of the frame of the camera. At the same time, the crescent Moon was setting in the west and gently illuminating Wukoki Pueblo. At the very top center of the photograph is Comet 46P/Wirtanen.

Geminid meteor, Comet 46P/Wirtanen and Wukoki Pueblo.

After about 1/2 hour of shooting meteors, I shot longer exposures of the comet. On this night, the comet formed a triangle with the Pleiades and Hyades star clusters. The image shown here is from ten 60-second images stacked using Deep Sky Stacker (DSS) and post-processed using rnc-color-stretch.

Comet 46P/Wirtanen with the Pleiades and Hyades star clusters.

A few nights later, the comet had moved so that it was between the Pleiades and Hyades clusters. Again, I shot a sequence of 60-second exposures totaling about one hour in duration—this time from the Mormon Lake overlook. The motion of the comet is quite apparent in this sequence of images. The first image shows the motion of the comet against the stars; the second is a time-lapse movie of the same sequence.

The motion of Comet 46P/Wirtanen is seen as a short streak in this one-hour composite image.

Time lapse movie showing the motion of Comet 46P/Wirtanen during a period of one hour.

Comet 46P/Wirtanen is now moving farther from Earth and will slowly dim in brightness but it will remain visible through binoculors, telescopes, and with digital cameras for many weeks or more. There is still plenty of time to see the comet if you haven’t already.

Comet 46P/Wirtanen, Rocket Launches, and Fog

December 9, 2018

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.

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.

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.

Bright Objects in the Morning Sky — December 2018

December 6, 2018

The other morning promised an interesting alignment of the planets Venus and Mercury, the waning crescent Moon (3.4% illuminated), and the bright star Spica (Alpha Vir, the brightest star in the constellation Virgo) in the morning sky. All that was required was clear skies.

Morning twilight with Mercury, Venus, Spica, and the Moon (0629 MST 05 December 2018).

Various weather models showed essentially the same forecast. There would be a band of high clouds to our northwest and another band to our southeast. Overhead it would be clear.

And the forecasts turned out correct. Below is a satellite image taken at ~1330 UTC (0630 MST) showing a nice clear gap in the clouds.

IR satellite image at 1332 UTC (0632 MST) showing the gap in the clouds across northern Arizona.

Model forecast for cloud cover. White/gray is cloud; black is clear.

I drove to the overlook on Mars Hill, home of Lowell Observatory, in Flagstaff. It has very good views towards the east and is a location I have used many times over the years for astrophotography.