Moon and Planets in the Evening Sky

On Monday and Tuesday (28-29 October 2019) the thin crescent Moon passed near the planets Venus and Mercury in the evening twilight sky. A check of The Photographers Ephemeris indicated that I could set up at Little Horse trailhead near Sedona and capture the thin crescent as it slipped between the spires of Cathedral Rock. Venus and Mercury would also be visible.

Ah, if only is was as easy as that. I never was able to see the crescent Moon.

A very thin crescent Moon sets behind Cathedral Rock.
A very thin crescent Moon sets behind Cathedral Rock.

But, wait! A closer inspection of the images shows that I did capture the crescent Moon. It was only 1% illuminated in a bright twilight sky. If you look carefully at the image and above the two people, you can just barely see a very thin crescent in the gap.

Venus and Mercury set behind Cathedral Rock.
Venus and Mercury set behind Cathedral Rock.

The next evening the Moon was 4% illuminated and higher in the sky making it an easy target. Venus and Mercury were below and the star Antares was to the left. Fitting all four objects in the image was the goal and I was successful. The only issue was the strong winds which resulted in some camera movement during the image capture.

Moon, Venus, Mercury, and Antares in evening twilight.
Moon, Venus, Mercury, and Antares in evening twilight.

I used Stellarium to determine how the Moon, planets, and stars would look at that time of the evening. I also used the Ocular plugin to show the field of view (FOV) of various lenses and focal lengths so that I could know, in advance, which lens would capture the whole scene. Very helpful!

Bright Objects in the Sky

The past few days have offered several opportunities for photographing objects in the sky.

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

Mercury (Magnitude –0.2) and Venus (Magnitude –3.9) are very low in the evening twilight right now and a bit difficult to see with the unaided eye—but a camera can do a better job at picking out the small but bright planets. The two planets are separated by about 7°.

Jupiter and the Moon in close proximity.
Jupiter and the Moon in close proximity.

At the same time, Jupiter (Magnitude –2.0) and the Moon made a close pass last night with about 2.5° of separation. These, of course, were much easier to see.

ISS passes in front of the Sun.
ISS passes in front of the Sun.

And, a few days ago, the International Space Station (ISS) flew in front of the Sun as seen from my house. I didn’t even have to travel—just set up the camera in the driveway. The entire flyby takes less than one second. Warning! A proper solar filter is required. I use a filter made by Kendrick Astro Instruments.

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 web site (or go directly to the Vimeo site).

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.