A few nights ago I had an opportunity to photograph the Milky Way under exceptionally clear skies. I wanted to do two things: One was to replicate an image I shot a few years ago and the other was to get a Milky Way/landscape composite with a moonlit foreground.
I headed out to Wupatki National Monument (an International Dark Sky Park) and set up in a dark parking lot with a moonlit landscape. The Moon was still well above the horizon and I took several long exposure images to get a good foreground. After the Moon had set, I shot the Milky Way (using a star tracker to eliminate star trails). Back at home, I would then merge the two images. The result is the image below showing the Milky Way aligned above the distant San Franciso Peaks with mesas rising on either side of the shallow valley. 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.
After completing this set of images, I moved to my next location to take my final shot. This is a single, 30-second image at high ISO (ISO 3200) with the tripod carefully centered on the stripe down the middle of the road. Comparing this shot with the one taken a few years ago indicates that the older image was blessed (if that’s the right word) with airglow in the lower part of the image giving it a much more interesting character. The newer image lacks this airglow but does have a more interesting horizon.
And now the North American Monsoon has begun to ramp up across the southwest and clear skies will be a rarity for the next few months. Time to start photographing storms and lightning!
It’s that time of year when the Milky Way is visible through much of the night. It is best observed when there is no Moon in the sky—and from very dark skies away from areas of light pollution. I wanted to capture both the Milky Way in a very dark sky and to capture Moonlight gently lighting up the still partially snow-covered mountains. So I headed out to Kendrick Park for some midnight sky photography.
The result is this composite of two images. The first was taken of the San Francisco Peaks as the moon was low in the west at around 1118 MST. This was a bit more than an hour before moonset (0030 MST). An exposure of 300 seconds at ISO 800 and an aperture of f/8 was used.
The second image was taken at 0047 MST shortly after the moon had set allowing the fainter stars in the night sky to appear. This image was also 300 seconds at ISO 800 and an aperture of f/5.6. To prevent streaking of the stars an iOptron Sky Tracker was used. The two images were then blended together.
Last week the two-day old crescent Moon (only 3.7% directly illuminated) provided a photo opportunity as it set over Upper Lake Mary. During the months of May, June, and July, the thin crescent Moon lines up with the long axis of Upper Lake Mary. This results in nice reflections of the Moon on the waters of the lake—but only if there is little or no wind. A bonus this month was the small planet Mercury was also setting in the northwest.
The image also shows the unlit part of the crescent Moon illuminated with Earthshine, also known as Da Vinci Glow. Yes, that Leonardo Da Vinci. Mercury can be seen just above the treetops on the far right side of the image.
With exceptionally clear skies it was a good time to capture images of the zodiacal light. Here is what Wikipedia has to say about this astronomical phenomenon.
Zodiacal light is a faint, roughly triangular, diffuse white glow seen in the night sky that appears to extend up from the vicinity of the Sun along the ecliptic or zodiac. It is best seen just after sunset and before sunrise in spring and autumn when the zodiac is at a steep angle to the horizon. Caused by sunlight scattered by space dust in the zodiacal cloud, it is so faint that either moonlight or light pollution renders it invisible.
Both images above clearly show the cone of light extending upward. In the upper portion of both images is the Pleiades star cluster with the planet Mars just below and to the left.
It’s unfortunate that Arizona’s dark skies aren’t as dark as they could be. Increasing population and expanding cities throws more light into the night sky. And our state legislators seem to think that bright billboards are more important than the dark skies needed by the many telescopes located in the state.
Comet C/2018 Y1 Iwamoto has just made its closest approach to Earth this week. With one evening of clear skies forecasted before the next storm system moves into the area, I went out earlier this week (02/11/2019) to capture images of this fast-moving, blue-green comet. The Moon was up in the western sky with 38% of the disk illuminated. This caused considerable brightening of the sky and made it challenging to capture fine details of the comet.
Discovered by Japanese amateur Masayuki Iwamoto as a +12th magnitude fuzzball moving through the constellation Hydra the Water Serpent on the night of December 18th, 2018, Y1 Iwamoto is a fast mover. It’s great to see that amateur astronomers can and still do discover comets, as the robotic competition posed by automated surveys such as PanSTARRS makes such an independent discovery tough these days…
At its closest on February 13th, Comet Y1 Iwamoto will appear to move seven degrees a day. This translates into a fast apparent motion of about 2/3rds the apparent diameter of a Full Moon, every hour.
The comet was easy to find with a pair of binoculars but was not visible to the unaided eye. Its position on this evening was near enough to the bright star Regulus that I had no trouble aligning the camera.
The following image and animation show the motion of the comet during a period of just over one hour.
Time lapse movie showing the motion of C/2018 Y1 during a period of one hour.
Comet C/2018 Y1 Iwamoto will make its next passage through the inner solar system in 3390 AD.
I have been looking forward to the recent Lunar eclipse (20 January 2019) since, well, the last one actually. During that eclipse, I shot images every three minutes while using an equatorial mount to track along with the stars. The results were good but there was some room for improvement. And that’s why I was looking forward to this event.
The weather had different plans for me. A stream of high-level tropical moisture was sitting right over Arizona all that day and most of the night. By late afternoon, the clouds were thick enough to partially obscure the sun. How was a darkened Moon going to shine through those clouds?
I could have just given up and stayed home but I was determined to at least try. I drove to Sedona to set up. Not because Sedona is a better place for viewing than Flagstaff but because Sedona is about 15 degrees warmer. And that matters.
I set up the tripod and then roughly aligned the iOptron Skytracker to where I made my best guess of the location of the star Polaris. Just as the umbral phase of the eclipse began, I was able to barely see Polaris through the thin clouds and completed the alignment of the tracker.
One of the things I learned last year was that three minutes was too large a time gap to make a smooth time-lapse video. My plan for this eclipse was to shoot at 1-minute intervals. But with the high clouds I realized that any time-lapse video was going to be challenging. So…3-minute intervals again. The clouds varied between fairly thick and mostly obscuring the moon to occasionally very thin allowing some lunar detail to be seen.
Here is a satellite image from GOES-16 showing the incredible stream of clouds moving across Arizona. I’m amazed that I got any photos at all!