Tis the Season for Night Shining Clouds


Noctilucent Clouds and Big Dipper

A bright display of noctilucent clouds last night prompts me to remind northerners to look north at this prime season for night shining clouds.

Noctilucent clouds (NLCs) can be seen only in summer and are best in the few weeks before and after (mostly after) summer solstice. I shot all these images in the middle of the night. Indeed, the two images above and just below are from 3 am on the morning of June 27.

NLCs are high altitude clouds at the edge of space some 80 kilometres above the Earth, far above any normal weather clouds. Their height allows sunlight streaming over the pole to illuminate them all night long.

Noctilucent Clouds over Pond
Noctilucent clouds at 3 am on June 27 over a prairie pond in southern Alberta. The NLCs were visible as an arc across the north for at least 2 hours and were still there as dawn twilight brightened at 3:30 am. This is looking due north with the bowl of the Big Dipper at upper left. Capella is at lower right. Shot with the 24mm lens.

Their cause is a mystery. They may form by water vapour condensing on meteoric dust particles.

They look luminescent, as if glowing on their own. But these are not auroras. They shine only by reflected sunlight.

And they have complex structures, with intricate waves and ripples.

Noctilucent Clouds (June 17, 2016)
A display of noctilucent clouds, the first good display of the season from my area of southern Alberta, on June 17/18. 2016. This is with a 105mm telephoto and the Nikon D750, and is the first frame of a 1000-frame time-lapse sequence. However, as the Sun dropped farther below the horizon the clouds did lose illumination and faded, from the top down.

And they move very slowly, as this time-lapse from June 17 shows.

Readers living at a latitude between 45° and 55° are best situated to see “NLCs.” From farther south the clouds will be below the horizon. From farther north the sky may be too bright with twilight and the angle of illumination wrong for optimum viewing.

For more information, check the Wikipedia article

Unlike auroras, there is no predicting when they might appear. Some nights when it is clear where you are, no NLCs appear. Perhaps that’s because of cloud much farther north blocking the path of light from the Sun on the other side of the planet to the clouds on our side of the Earth.

But by the end of July NLC season is coming to an end as the Sun drops farther below the northern horizon at night, and the nights get darker.

So over the next four weeks, look low in the north for night shining clouds.

— Alan, June 27, 2016 / © 2016 Alan Dyer / www.amazingsky.com 

 

Glows and Streaks in the Spring Sky


The Spring Sky over the Pioneer Farmstead

How many sources of skyglow can you pick out here?

There are at least five:

• the Milky Way (at left),

• green airglow (below the Milky Way),

• all too prevalent light pollution (especially reflected off the clouds coming in from the west at right),

• lingering blue twilight across the north (at left and right), common in May and June from my northern latitude,

• and even a touch of aurora right at the northern horizon at far left.

In this scene from May 28, the Milky Way arches over an abandoned pioneer farmstead from the 1930s and 40s near my home in southern Alberta.

Mars (very bright and in some clouds) and Saturn shine at lower centre, while Jupiter is the bright object in clouds at right just above the old house.

Arcturus is the brightest star here at upper right of centre, made more obvious here by shining through the clouds. The Big Dipper, distorted by the map projection used in the this panorama, is at upper right.

Technical: This is a 360° horizon to zenith panorama taken with the iPano motorized panning unit, using the 24mm lens at f/2.8 and Nikon D750 at ISO 6400, for a stitch of 28 panels, in 4 tiers of 7 segments each. Stitched with PTGui. South is at centre, north to either end. The original is 25,700 x 7,700 pixels.

Just after I shot the panorama I captured the International Space Station passing directly overhead in one of several passes this night.

ISS Pass #2 (May 28/29, 2016)
The second Space Station pass of May 28/29, 2016, at 1:40 a.m., with cloud moving in adding the glows to all the stars. Taken with the 8mm fish-eye lens from home. The Big Dipper is high in the west at right. Mars is bright at bottom, to the south. Several other satellites are in the sky as well. This is a stack of 3 exposures, each 2.5-minutes with the camera on the Star Adventurer tracker.

At this time of year the ISS is lit all night by the Sun that never sets for the astronauts. We see the ISS cross the sky not once but several times in a night at 90-minute intervals.

While the sky near solstice is never dark at my latitude, it does have its compensations and attractions.

— Alan, May 29, 2016 / © 2016 Alan Dyer / AmazingSky.com

 

Circles and Lines in the Dawn Sky


A classic 22° ice crystal halo around the waning crescent Moon, here overexposed, with the Moon between Jupiter and Mars in the morning sky on December 5, 2015. Seeing a halo around a crescent Moon is somewhat rare as they usually require the brighter light of the Full Moon. Venus is the brightest object at bottom closest to the horizon. The three planets, along with the stars Spica (above Venus) and Regulus (at top of frame) define the line of the ecliptic here in the dawn late autumn / early winter sky. I captured this scene from southeast Arizona near the Arizona Sky Village at Portal. This is a stack of 4 exposures from long to short (8s to 1/2s) to encompass the great range in brightness and not overexpose the crescent Moon too much. Images were layered in Photoshop and masked with luminosity masks. Automatic HDR techniques did not work well as the shortest image was too dark for ACR to find content to register in Merge ot HDR, and in Photoshop the HDR Pro module left visible edge artifacts. The camera was on the iOptron Sky Tracker to follow the sky and register the sky for all the exposures, thus the slightly blurred ground. Taken with the Canon 6D and 15mm full-frame fish-eye lens.

Cloud hid Comet Catalina but added a halo around the waning Moon, intersected by the line of the ecliptic.

I’m in Arizona, just inside the state line with New Mexico, on a quest to shoot Comet Catalina at dawn. Clouds prevented any view of the faint comet this morning but provided a fine consolation prize.

The waning crescent Moon was surrounded by an ice crystal halo, a rare sight around a thin Moon. The Moon was between Mars and Jupiter, heading toward a conjunction with Venus, below, on December 7.

The line of Venus, Mars, the Moon, and Jupiter, plus the stars Spica and Regulus defined the line of the ecliptic beautifully in the pre-dawn sky.

A classic 22° ice crystal halo around the waning crescent Moon, here overexposed, with the Moon between Jupiter and Mars in the morning sky on December 5, 2015. Seeing a halo around a crescent Moon is somewhat rare as they usually require the brighter light of the Full Moon. Venus is the brightest object at bottom closest to the horizon. The three planets, along with the stars Spica (above Venus) and Regulus (at top of frame) define the line of the ecliptic here in the dawn late autumn / early winter sky. I captured this scene from southeast Arizona near the Arizona Sky Village at Portal. This is a stack of 4 exposures from long to short (8s to 1/2s) to encompass the great range in brightness and not overexpose the crescent Moon too much. Images were layered in Photoshop and masked with luminosity masks. Automatic HDR techniques did not work well as the shortest image was too dark for ACR to find content to register in Merge ot HDR, and in Photoshop the HDR Pro module left visible edge artifacts. The camera was on the iOptron Sky Tracker to follow the sky and register the sky for all the exposures, thus the slightly blurred ground. Taken with the Canon 6D and 15mm full-frame fish-eye lens.
This is a stack of 4 exposures from long to short (8s to 1/2s) to encompass the great range in brightness and not overexpose the crescent Moon too much. Images were layered in Photoshop and masked with luminosity masks. Automatic HDR techniques did not work well as the shortest image was too dark for ACR to find content to register in Merge ot HDR, and in Photoshop the HDR Pro module left visible edge artifacts.
The camera was on the iOptron Sky Tracker to follow the sky and register the sky for all the exposures, thus the slightly blurred ground. Taken with the Canon 6D and 15mm full-frame fish-eye lens.

It was a show of circles and lines, real and imagined, in the morning sky.

With luck, clouds will clear to reveal Comet Catalina, which is likely fainter and less spectacular than hoped. But such is the way of comets. Regardless of what the comet does, it is a good time to be in the desert southwest, typing this blog on a sunny front porch under blue desert skies.

— Alan, December 5, 2015 / © 2015 Alan Dyer / www.amazingsky.com

 

Morning Star, the Milky Way, and the Zodiacal Light


Venus shines brightly, and nearly at its brightest at magnitude -4.7, in the dawn sky on a very frosty morning at 5 am, on September 17, 2015, from home in southern Alberta. Venus appears amid the faint glow of the Zodiacal Light, sometimes called the “False Dawn,” stretching vertically from the dawn horizon in the east, up and to the right, and reaching the Milky Way that runs down the frame from top centre to bottom right. Orion and the winter stars shine in the Milky Way, with Sirius above the trees at lower right. The Beehive Cluster, M44, appears as the small group of stars above Venus. The Pleiades, M45, is at top right. Mars is the brightest object left of Venus, with the bright star Regulus just below it and rising in the east. The stars of the Big Dipper are at far left at the edge of the frame. The sky is beginning to brighten with the real glow of morning.  This is a stack of 4 x 2-minute exposures, tracked and mean combine stacked, for the sky and 2 x 2-minute exposures, untracked and stacked, for the ground to minimize blurring in the starlit ground. The Canon 6D was on the iOptron Sky-Tracker, shooting at ISO 1250 with the 15mm full-frame fish-eye lens at f/3.5. The stacking with a mean combine stack mode smooths noise in both sky and ground.

Venus, now at its brightest as a morning star, shines amid the subtle glow of the Zodiacal Light. 

This was the scene this morning, September 17, on a very frosty dawn at 5 a.m. from my backyard in southern Alberta.

Here, Venus shines nearly as bright as it can be, at magnitude -4.7, in the dawn sky as a brilliant “morning star.”

Venus appears amid the faint glow of the Zodiacal Light, sometimes called the “False Dawn,” stretching diagonally from the dawn horizon in the east, up and to the right, and reaching the Milky Way that runs vertically down the frame from top centre to bottom right.

Orion and the winter stars shine in the Milky Way, with Sirius above the trees at lower right.

The Beehive Cluster, M44, appears as the small group of stars above Venus. The Pleiades, M45, is at top right.

Mars is the brightest object left of Venus, with the bright star Regulus just below it and rising in the east. The stars of the Big Dipper are at far left at the edge of the frame.

The sky is beginning to brighten with the real glow of morning. It was a marvellous dawn sky delight.

Technical notes:

This is a stack of 4 x 2-minute exposures, tracked and mean-combine stacked, for the sky and 2 x 2-minute exposures, untracked and stacked, for the ground to minimize blurring in the starlit ground. The Canon 6D was on the iOptron Sky-Tracker, shooting at ISO 1250 with the 15mm full-frame fish-eye lens at f/3.5. The stacking with a mean combine stack mode smooths noise in both sky and ground.

– Alan, September 17, 2015 / © 2015 Alan Dyer / www.amazingsky.com 

The Dancing Northern Lights


A still frame from a 865-frame time-lapse movie taken the morning of Sept. 9, 2015 from the back deck, using the Nikon D750 and 24mm lens for 2-second exposures for a fast cadence. Focus is soft.

The lights came out and danced in my sky in the early morning hours.

The early warning signs weren’t calling for anything too impressive for a display last night, September 8/9, but the sky surprised us with a fantastic display of Northern lights.

I shot with one camera – it was very late, or very early! – but shot enough frames to create this short 1.5-minute music video.

I photographed the sequence with a single fixed-camera aimed east toward a bright auroral curtain, showing fast pulsing forms common to the later stages of a substorm. But then a new bright curtain sweeps in from the north and the display brightens even more in a new substorm. The display then fades.

The exposures were taken over an hour from 1:30 a.m. to 2:30 a.m. MDT. Each was a 2-second exposure with an interval of 2 seconds, shot with the Nikon D750 at ISO 3200 and Sigma 24mm lens at f/2, for a total of just over 850 frames.

Music is my Adi Goldstein at AGSoundtrax.com.

— Alan, September 9, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Sunset over Horsethief Canyon


Sunset on August 1, 2015 at the Horsethief Canyon Viewpoint overlooking the Red Deer River, north of Drumheller, Alberta, on the Dinosaur Trail scenic drive. The name comes from the pioneer days when horses would get lost in the Badlands here and then re-emerge found, but with a new brand on them. The region is home to rich deposits of late Cretaceous dinosaur fossils. Just south of here is the world class Royal Tyrrell Museum, a centre of research into dinosaurs and prehistoric life.  This is a single-exposure frame (not HDR) from a 300-frame time-lapse sequence, with the Canon 6D and 16-35mm lens.

The Sun sets over the Red Deer River Badlands at Horsethief Canyon

This was sunset last night, Saturday, August 1, at the Horsethief Canyon Viewpoint overlooking the Red Deer River, north of Drumheller, Alberta.

The viewpoint is one stop on the Dinosaur Trail scenic drive that winds up and down the river valley, with a crossing just north of here by one of the few remaining river ferries in Alberta, the historic Bleriot Ferry.

The Canyon’s name comes from the pioneer days when horses would get lost in the Badlands here, then re-emerge found, but with a new brand on them.

The region is home to rich deposits of late-Cretaceous dinosaur fossils. Just south of here is the world-class Royal Tyrrell Museum, a centre of research into dinosaurs and prehistoric life.

This is a single-exposure frame (not HDR) from a 300-frame time-lapse sequence, with the Canon 6D and 16-35mm lens.

– Alan. August 2, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Worlds Amid the Sunset Clouds


The waxing crescent Moon below Venus low in the sunset colours of a July summer evening over the waters of Little Fish Lake, in southern Alberta. Jupiter is at upper right but much fainter.  This is a 3-segment panorama taken with the Canon 60Da and 18-200mm Sigma zoom.

The thin waxing Moon shines near Venus above the colourful clouds of sunset.

Tonight, July 18, was the evening of a close conjunction of the crescent Moon near Venus in the evening sky. From my latitude at 50° North, the conjunction was going to be low, and at risk of clouds.

In this case, the clouds added to the scene as they lit up with sunset colours.

You can see the Moon and Venus at centre, while fainter Jupiter is at upper right, and perhaps not visible on screen at this scale.

The location is one I used last month for the Venus-Jupiter meeting, Little Fish Lake and Provincial Park, north of Drumheller. It’s a quiet spot. This Saturday night there were just three families there camping.

I shot this telephoto panorama with my red-sensitive Canon 60Da, which is designed to record red nebulas well, but does a nice job on punching up sunsets, too!

Alas, the clouds that painted the sky so nicely here, moved in as the worlds set lower. I wasn’t able to shoot them closer to the horizon amid the deep colours of a late twilight. But I’ll settle for this image.

– Alan, July 19, 2015 / © 2015 Alan Dyer / www.amazingsky.com