Venus and the Crescent Moon in Evening Twilight

A few days ago the Moon and Venus were very close together in the evening twilight sky. At sunset on Friday, the two objects were about 3° apart—about six moon diameters—with the Moon located up and to the left of Venus.

Crescent Moon and Venus in evening twilight.
Crescent Moon and Venus in evening twilight.

To view this I wanted a location with a very low western horizon. I chose to visit Navajo Point on the South Rim of Grand Canyon National Park. From this location, the rim to my southwest was actually slightly lower than my position giving me an unobstructed view.

There was a nice sunset to start off the evening. The clouds were lit up and there was still enough light to fill in the lower canyon.

Sunset at Navajo Point, Grand Canyon.
Sunset at Navajo Point, Grand Canyon.
Twilight at Grand Canyon.
Twilight at Grand Canyon.

The moon was only one day past New Moon and was about 1.4% illuminated although there was a bit of Earthshine helping to illuminate the entire disk.

Setting moon over the South Rim of Grand Canyon.
Setting moon over the South Rim of Grand Canyon.

As the Moon approached the horizon, atmospheric effects resulted in the lower limb of the Moon being distorted. The final image is a composite taken over several minutes prior to moonset. In this composite it is easy to see the distortion of the lower limb.

An Early Morning Lunar Eclipse

It was worth it.

Getting up early in the morning, driving to a location with a good western view, and then standing around for many hours taking photos of the lunar eclipse.

Yes, it was worth it. But I was very cold by the time it was over.

Four stages of the total lunar eclipse of 31 January 2018.
Four stages of the total lunar eclipse of 31 January 2018.

This lunar eclipse has been referred to as the “Super Blue Blood Moon” eclipse. What does that even mean? Okay—here is an informative article written by an astronomer on how these terms came to be part of our jargon for this eclipse.

Anyway…

I had considered many possibilities how to photograph the lunar eclipse including interesting foregrounds, multiple exposures, and even video. Some examples of single and multiple images can be found in this blog for 2014 and 2015 eclipses taken during the recent Lunar Eclipse Tetrad of 2014-2015. A tetrad is a series of four consecutive total eclipses occurring at approximately six month intervals. It’s now been a bit more than two years since the last lunar eclipse visible around here and I was ready for another.

Start of totality.
Start of totality.

Eventually I decided to try something a bit different from previous events. I would mount the camera on the iOptron SkyTracker so that the camera would follow the stars. From these images, I would construct a time-lapse of the eclipse as it went through its different phases. With the SkyTracker, the stars would remain fixed while the moon would slowly move across the sky relative to the stars—and the Earth’s shadow.

Mid-totality of Lunar Eclipse.
Mid-totality of Lunar Eclipse.

It worked pretty well but I did manage to bump the camera a few times as I was changing exposure settings. I had considered using a phone application that could change the settings on the camera so I would not have to touch it—but the power drain when WiFi was active was unacceptable. I would probably need to change the battery during the eclipse—which put me right back in the same situation of jostling the camera. Okay—just keep it simple. No WiFi, adjust by hand, and be careful.

The image at the top of this entry is a composite of four stages of the eclipse. P1 is the first stage when the Moon enters the Penumbral shadow of the Earth. Only a subtle darkening occurs during this stage. U1 occurs when the Moon first enters the umbral shadow and the darkening along one edge is very distinct. U2 is the beginning of totality. Mid-totality is the darkest stage of the eclipse.

The second image shows the start of totality. There is a brief period near the start and end of totality in which the limb of the moon can have a bluish cast to it. Lunar eclipse researcher Rich Keen says:

“Most of the light illuminating the Moon passes through the stratosphere, and is reddened by scattering. However, light passing through the upper stratosphere penetrates the ozone layer, which absorbs red light and actually makes the passing light ray bluer.”

This can be seen as a turquoise-blue fringe around the red. And here we have an image taken just a few minutes after totality began that shows some blue along the lower limb.

A few minutes after totality ended---and a few minutes before moonset.
A few minutes after totality ended—and a few minutes before moonset.

Stages P1, U1, U2, and mid-totality were all visible with a very dark sky. U3 (end of totality) occurred during morning twilight; U4 and P2 both occurred after Moonset.

The time-lapse sequence was shot with 3-minute intervals. This is a good interval if you want to composite images as the moon has moved a full diameter plus a bit more in three minutes so that individual frames do not overlap. Three minutes, however, is too long a time for a smooth time lapse. Lesson learned for the next event!

The animation of the eclipse starts at P1 and ends just as the moon sets. The exposure was changed during totality and stars become visible. Later, twilight brightens the entire sky and, at the end, the distant mountains can be seen as the moon sets in the west.

 

The next total Lunar Eclipse will occur 27 July 2018 but will not be visible from any part of North America. The next North American total lunar eclipse will occur on 21 January 2019.

Edit: corrected dates.

Mountain Biking — Winter 2018

If you have been following along you already know that it has been a warm and very dry Autumn and Winter around these parts. As a result of the dryness, most trails deteriorated and became “moon dust” that fills the air as you walk or ride on the trail.

We’ve avoided mountain biking during the dry periods because of the excessive dust and loose soils on the trails—believing that riding under these conditions accelerates the deterioration of the trails. But now that we’ve had some rain—and high-country snow—we’re back out on the trails.

Here are a few photographs from some recent mountain bike rides.

HiLine (a/k/a Highline) Trail in Sedona.
HiLine (a/k/a Highline) Trail in Sedona.
Lower Raptor Trail in Dead Horse Ranch State Park.
Lower Raptor Trail in Dead Horse Ranch State Park.
Rust Bucket Trail (and the rusty buckets) in Dead Horse Ranch State Park.
Rust Bucket Trail (and the rusty buckets) in Dead Horse Ranch State Park.

 

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.

 

 

And, finally, we have some weather

It has been a very dry autumn and early winter around these parts—but that finally changed as a winter storm moved across the area yesterday and today. On Tuesday afternoon clouds began to increase across the area and there was a cap cloud draped across the San Francisco Peaks.

Clouds cover the San Francisco Peaks as a winter storm approaches Arizona.
Clouds cover the San Francisco Peaks as a winter storm approaches Arizona.

Most, but not all, of Arizona received precipitation including Flagstaff. We have been without any significant precipitation since September 27 when 0.07″ of rain fell. Since then, we’ve had 0.01″ on November 17 and a Trace on December 21. That’s it. It’s been the driest period on record and the second latest first snowfall of the season. And it’s been warm.

Water vapor satellite image of the winter storm approaching Arizona.
Water vapor satellite image of the winter storm approaching Arizona.

Rain began to fall around 7:30 P.M. Tuesday evening then switched to snow around 10:15 P.M. as the cold front moved across the area. Prior to frontal passage we had several rounds of thunderstorms. At least one of these thunderstorms exhibited extreme right-mover characteristics as well as some weak rotation suggesting it may have been a supercell. With this winter storm Flagstaff received ~5″ of snow and 1.19″ of total water.

Location of lightning strikes as the cold front advanced across Arizona.
Location of lightning strikes as the cold front advanced across Arizona.

Although it was still mostly cloudy this morning, there was a gap in the clouds along the eastern horizon allowing sunshine to briefly illuminate the peaks shortly after sunrise.

San Francisco Peaks wrapped in early morning clouds.
San Francisco Peaks wrapped in early morning clouds.
Mormon Mountain and Mormon Lake at sunrise.
Mormon Mountain and Mormon Lake at sunrise.

The San Francisco Peaks are almost completely wrapped in clouds with only the summits visible. A few minutes later, the sun had risen high enough that it was above the clear gap and everything turned gray again.

This will be a short-lived episode as the forecast indicates a quick return to warm and dry conditions across the southwest.