Aurora!

One of the attractions of the Salmonberry tour in Fairbanks was the opportunity to see the northern lights.  Fairbanks is well-positioned with respect to the auroral oval so that on most evenings, if the sky is clear, one can see them.  And we were there at the vernal equinox– spring:  the weather was moderating, meaning that the daytime temps were approaching melting and at night they kept mostly above zero.  At this high latitude however, the days are lengthening rapidly, and in a few more weeks, there won’t be much night left to see northern lights.

It was nice that the tour was focused on aurora viewing.  There is always uncertainty: the aurora is not active every night, and clouds frequently obscure them when they are.  To maximize the chance that we would see some northern lights sometime during the tour, three nights were scheduled for such viewing.  Each took us to a viewing site away from the lights of Fairbanks and accommodated the needs of aurora viewers:  a warming house, coffee and snacks, and alternate activities in the event of poor viewing.  Oh, and a wifi connection so we could monitor the online real-time aurora activity reports being fed by satellites and observers on the ground. 

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“Coffee Table Nightscapes” goes to print!

I finally caught up with my blog postings of past nightscape photos to reach the ones I made this last year. And I have now completed their assembly into a printed photo book.

I didn’t realize when I started this project that the pictures would span 25 years, and that they happened to straddle the transition from film photography to digital. The chronological order reveals the change in technology as I pursued my various night sky targets.

For completeness, I posted the preface and introduction as blog entries, but their real place is in the leading pages of the printed book where all the photos are collected under one cover. I was pleased to be able to give copies of it to my family and close friends this holiday season. Not all of them have coffee tables, but I hope they find a place for it.

Although this marks the end of this particular project, I doubt that I am really done. As mentioned in the epilogue, the capabilities of cameras just keep improving and so I am now excited to start the next 25 years of taking pictures of the night sky!

Milky Way Sails the Playa

Racetrack Playa is a dry lakebed in Death Valley.  It is a vast expanse, miles by miles, of dried mud cracks.  It is flat and nearly level, the north end merely inches higher than the south.  The occasional stone can be found on the playa, delivered by erosion forces on the surrounding mountains, falling down and rolling out onto the lakebed.  They are stones, not boulders, maybe a foot or two across, heavier than is convenient to carry away, but not heavy enough to protect them from magic seekers.

And the magic they seek is that many of the stones are found at the end of a long, physically engraved trail, recording their traversal of the ancient lakebed.  How could these stones have moved across the dry playa?  It has been a mystery to geologists for years.  Various theories have been proposed, and some have been tested, but it is a difficult research project.  The stones lie inert for years, and then, when next inspected, they have moved.  With new trails marking their path!  This is the magic that the stone thieves are after.

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Polaris on the Playa

One of the active topics in modern photography is the distinction between “blends” (combining multiple exposures from a single camera viewpoint), and “composites” (which combine unrelated images into a synthetic scene).  Both are valid uses of photography, but I prefer to limit my efforts to the former, hoping to reveal some scientific beauty in the result.

In this case the relative motion of the stars is “stacked” (added) from 2,335 10-second exposures.  Each frame looks like a normal picture of the sky, but when accumulated creates the star trail effect.  The frames were selected from the period after “astronomical twilight” when the sun is more than 18-degrees below the horizon.  On this date, official night lasted over six hours, and the star trails cover more than 1/4 of a full circle (and even Polaris shows that it is not exactly on the north celestial pole).

Although it was “night”, it was not completely dark.  The moon was up and illuminated the scene until it set around midnight.  This allows the foreground to show, including the “sailing stone” with its path on the dry lakebed trailing behind it, a contrast of time scales against the motion of the sky.

A final detail to explain:  the streaks below and to the left are the result of trains of Starlink satellites moving across the sky.  Dozens of satellites follow each other into and out of the sunlight at their altitude, reflecting it down to our observing position on the playa and creating its own trail on this image.

For more of the backstory on making this image and the next, see “A Night on the Playa – Part 2“.

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19 May 2021
Racetrack Playa
Death Valley National Park CA
Canon EOS Ra with EFS 10-22mm
2335 exposures, 8 sec @ f/4, ISO 3200 (6-1/2 hours)


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Wupatki Startrails

“The Citadel” remains the focus for this startrail image.  The moon dominates the scene, and this blend of exposures shows its path among the stars.

The cloud persisted above the monument over the course of the exposure, growing and shrinking, but never moving away or evaporating.

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15 May 2021
Wupatki National Monument
Flagstaff AZ
Canon EOS 6D with Sigma 14mm f/1.8
458 exposures, 8 sec @ f/2, ISO 3200 (76 minutes)


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Wupatki Moon

“The Citadel”, one of the structures built by indigenous people who lived here from 500-1200 CE, provides a focus for a nighttime exposure.  The Arizona skies are clear except for a cloud condensed by the contrasting air flows over the monument. 

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15 May 2021
Wupatki National Monument
Flagstaff AZ
Canon EOS 6D with Sigma 14mm f/1.82 sec @ f/2, ISO 3200


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Moonflowers

I had another camera in the sunflower field.  This one faced south and caught the arcs of stars and planets near the ecliptic.  Eventually the full moon entered the scene.

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2 September 2020
Otsego MN
Canon EOS 6D with EF 17-40mm(@17mm)
Blended 10 sec intervals  at f/4, ISO 800, 1/2 hour elapsed


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Northern Sunflower Trails

I have long been fascinated by sunflowers.  On my travels across the prairies of the Dakotas I loved to encounter sunflower fields with their collective bright yellow heads all aimed in the same direction.  

It is generally known that sunflowers track the sun across the sky, from east to west.  I wondered what happens after sunset, when the flowers would all be facing west.  With no phototropism to guide it, how would they get ready for the eastern sunrise?  Would they be caught off-guard in the morning and suddenly swing their heads back at the risk of floral whiplash?  Or is there a gradual re-setting of the neck-stalk fibers back to an easterly gaze?

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Comet Neowise

A photogenic comet visits in a year when the world is shut down by a virus.  We can still appreciate its beauty and find an isolated area in a nearby park.  Photographing comets has become considerably easier in the twenty years since my previous attempts trying to capture Comet Hale-Bopp on film!

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Excelsior, MN
20 July 2020
Canon EOS Ra with 70-200mm (200)4 sec, f/2.8, ISO 1600


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