Milky Way, Moon, and Mercury

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 Milky Way rises above the San Francisco Peaks in northern Arizona.
The Milky Way rises above the San Francisco Peaks in northern Arizona.

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.

This is similar to images taken in the past of Cathedral Rock and Wukoki Pueblo with the Milky Way rising above. Also present low in the photograph is airglow (or nightglow).


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.

A thin crescent Moon throws a large reflection in Lake Mary, Flagstaff, Arizona.
A thin crescent Moon throws a large reflection in Lake Mary, Flagstaff, Arizona.

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.

Bright Objects in the Morning Sky — December 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).
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.
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.
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.

Venus and Mercury in Evening Twilight

Earlier this year in March the planets Venus and Mercury were close to each other in the evening sky. The crescent Moon also joined the two planets one evening (18 March 2018) resulting in a photogenic scene in the western twilight sky.

Mercury faded from view shortly thereafter and shifted into the morning sky. However, Mercury recently reached superior conjunction (06 June 2018) passing from the morning back into the evening sky. So, once again, Venus and Mercury share the western twilight sky. Mercury will continue to climb higher in the sky through mid July when the two planets will be at their closest approach.

Venus and Mercury in evening twilight.
Venus and Mercury in evening twilight.

A very nice animation of the positions of Venus and Mercury, as well as Jupiter and Saturn, can be seen the Shadow and Substance website video.

Exceptionally clear skies resulted in these images of Venus high in the western sky with Mercury much lower and a bit more difficult to see in the bright evening twilight. Mercury should become easier to see over the next few weeks.

Bright Objects in the Night Sky: Venus, Mercury, and the Moon

A bit over a week ago (18 March 2018), we had a triple conjunction in the sky. Venus and Mercury had been in the evening sky for a few weeks—and now a crescent Moon was going to join them in the evening. Weather permitting, I was interested in capturing images of this event. I headed out towards the Mormon Lake Overlook which would give me a good view of the western sky as well as the possibility of reflections of these sky objects in the shallow waters of the lake.

While waiting for the sky to darken, I was treated to a few minutes of sunset colors on some interesting wave clouds. More on that below.

Conjuction of Mercury, Venus, and the Moon.
Conjuction of Mercury, Venus, and the Moon.

The Moon and Venus are easily visible in this image taken at 7:20 P.M. MST while Mercury is a bit harder to see to the right and above Venus. A second image taken at 7:29 P.M. shows all three bodies quite clearly. And, as I had hoped, there were reflections in the water.

Conjuction of Mercury, Venus, and the Moon.
Conjuction of Mercury, Venus, and the Moon.

This is how Venus and Mercury looked earlier in the month.

Venus and Mercury in the evening sky.
Venus and Mercury in the evening sky.

Now, back to the wave clouds.

Long and thin wave clouds in the evening sky.
Long and thin wave clouds in the evening sky.

Although they look like jet contrails, these were actually long and thin wave clouds. As the sun began to set, the colors were briefly quite amazing.

Sunset colors on wave clouds.
Sunset colors on wave clouds.
Sunset colors on wave clouds.
Sunset colors on wave clouds.

It was an fun evening: Interesting clouds and a triple conjunction.

It was also cold…

Four Planets and the Moon

This week the waning moon joined four planets in the eastern sky. Lowest to the horizon was Mercury with Saturn just above. The moon was located well above that pair. And high in the sky were Mars and Jupiter.

Earlier this month on 07 January 2018, Mars and Jupiter were in conjunction. The pair was only 0.25 degrees apart in the sky at its closest. By comparison, the full moon is approximately 0.50 degrees. And, then, on 13 January 2018, Mercury and Saturn were in conjunction—but not quite as close as the Mars-Jupiter conjunction.

On the 14th and 15th, the Moon was just above and just below the pair of Mercury and Saturn.

The waning crescent moon (~5% illuminated) sits above the planetary pair of Mercury and Saturn.
The waning crescent moon (~5% illuminated) sits above the planetary pair of Mercury and Saturn.
A wider view shows all four planets (Mercury and Saturn low; Mars and Jupiter high) plus the moon.
A wider view shows all four planets (Mercury and Saturn low; Mars and Jupiter high) plus the moon.

I had planned to photograph on both days but clouds intervened. All I got was this thin crescent Moon (~2% illuminated) that was visible for only a few minutes before it was obscured by clouds.

A thin crescent moon is visible for just a moment after moonrise.
A thin crescent moon is visible for just a moment after moonrise.

Coming up: at the end of the month there will be a total lunar eclipse that will be visible in the pre-dawn hours of the western states. I hope the skies are clear.