The Dancing Lights over Dinosaur Park


The Northern Lights over the badlands of Dinosaur Provincial Park, Alberta, on September 11, 2015. This is one frame from a 280-frame time-lapse sequence. Although, in this image the ground came from a later exposure in the sequence when passing car headlights lit the ground briefly on an otherwise dark, moonless night, to help sculpt the ground. This was with the Nikon D750 and 24mm lens for 15 seconds at f/2.8 and ISO 6400.

The Northern Lights dance over the badlands of Dinosaur Provincial Park, a World Heritage Site.

Aurora alerts called for a fine display on Friday, September 11. Forewarned, I headed to one of my favourite shooting spots at Dinosaur Provincial Park, and aimed three cameras at the sky. It didn’t take long before the lights appeared, right on cue.

An aurora and the autymn Milky Way over the Badlands of Dinosaur Provincial Park, Alberta, on September 11, 2015. The stars, constellations and Milky Way of the autumn and early winter sky are rising in the northeast, including the objects: the Andromeda Galaxy at top, and the Pleiades at bottom.  This is one frame from a 200-frame time-lapse sequence, though in this image the ground comes from a Mean Combine stack of 7 images to smooth noise but the sky is from one image, each 30 seconds at f/2.8 with the Rokinon 14mm lens and Canon 5D MkII at ISO 3200 on a dark moonless night.

The display started out with lots of promise, but did fade after 12:30 a.m., just when it was supposed to be peaking in intensity. I let the cameras run for a while but eventually stopped the shutters and packed it in…

…But not before I captured this odd bit of aurora in the east, shown below, that appeared as an isolated and stationary band pulsing up and down in brightness, but with little movement.

An odd isolated arc of aurora in the eastern sky over the badlands of Dinosaur Provincial Park, Alberta, on September 11, 2015. This arc sat stationary and pulsed up and down in brightness over a few seconds. It was in some frames but not others. The winter stars of Taurus, including the Pleiades cluster, and Auriga are rising in the east.  The sky here is from a single exposure but the ground came from a Mean Combine stack of 8 exposures to smooth noise. Each was 40 seconds at f/2.8 with the 14mm Rokinon lens and Canon 5D MkII at ISO 3200 on a moonless night.

I’ve seen these before and have never heard a good explanation of what process creates such an effect, with a patch of sky appearing to “turn on” and off.

You can see the effect at the end of the time-lapse compilation, linked below from Vimeo.

As usual, please enlarge to full-screen and watch in HD for the best quality.

Unfortunately, a patrolling park official checking on things, spoiled some frames with her truck’s headlights. It’s one of the hazards of time-lapse imaging.

As a final image, here are all the fish-eye lens frames stacked into one image, to create a single star trail showing the sky rotating about the celestial pole.

A composite stack of 198 images creating a circumpolar star trail image of the entire sky, with the motion of the stars and the Northern Lights over an hour recorded onto one frame.  The 8mm fish-eye lens take in almost all the sky, with the camera aimed northeast to the centre of the auroral arc, with Polaris, the centre of the sky’s rotation, at left. The scene is at Dinosaur Provincial Park in Alberta, from September 11, 2015.  Each exposure was 20 seconds at f/3.5 with the Sigma 8mm lens and at ISO 6400 with the Canon 6D. The ground comes from a stack of 16 images taken early in the sequence turned into a smart object and mean combined with Mean stack mode, to average out and smooth noise. The sky comes from 198 exposures, Lighten stacked using the Advanced Stacker Actions from StarCircleAcademy.com.
Each exposure was 20 seconds at f/3.5 with the Sigma 8mm lens and at ISO 6400 with the Canon 6D. The ground comes from a stack of 16 images taken early in the sequence turned into a smart object and mean combined with Mean stack mode, to average out and smooth noise. The sky comes from 198 exposures, Lighten stacked using the Advanced Stacker Actions from StarCircleAcademy.com.

It’s been a good week for auroras, with a promise of more to come perhaps, as we approach equinox, traditionally a good time for magnetic field lines to align, funnelling solar storm particles into our magnetosphere.

Keep looking up!

— Alan, September 13, 2015 / © 2015 Alan Dyer / www.amazingsky.com 

Ancient Solar Observatory at Fajada Butte


Sun over Fajada Butte at Chaco Canyon

Sunlight and shadows at Fajada Butte served to mark the seasons a thousand years ago.

In the distance is Fajada Butte at Chaco Canyon, New Mexico. It is one of the most famous sites in archaeoastronomy. A thousand years ago, people of the Chaco Culture used it to observe the Sun.

Fajada Butte at Chaco Canyon

At a site now off limits to preserve its integrity, a set of three rocks cast shadows and daggers of sunlight onto a carved spiral petroglyph.

Fajada Butte Sign At Chaco Canyon

People used the position of the projected beams of light as a calendar to mark time through the year. In truth, simply watching the changing position of the rising and setting Sun along the horizon, which was also done here at Chaco Canyon, would have worked just as well.

Fajada Butte Viewpoint at Chaco Canyon

I visited the site today, as part of a trek north through New Mexico, Arizona and into Utah. Chaco Canyon is one of the preeminent sites for archaeoastronomy, demonstrating how well people a thousand years ago (the site was occupied from the mid 800s to the mid 1100s) observed the sky.

For example, a half-day hike takes you to a famous pictograph on a rock face showing a bright star near the crescent Moon, a drawing some have interpreted as being an observation of the supernova of 1054 AD.

Grand Kiva at Chetro Ketl, Chaco Canyon

In its height, thousands of people lived in the pueblos at Chaco Canyon and surrounding area. This is the Great Kiva at the Chetro Ketl pueblo. Wood columns used to hold a wood roof over this structure to make a space for ceremony and ritual.

Iridescent Clouds at Chaco Canyon

I did a little solar observing myself while there. While walking through the maze of rooms at Pueblo Bonito I looked up to see iridescent clouds near the Sun, created by diffraction of sunlight from fine ice crystals.

Public Observatory at Chaco Canyon, New Mexico

In keeping with the site’s astronomical heritage, the Visitor Centre at the Chaco Culture Historical Park has a well-equipped observatory with several top-class telescopes (a 25-inch Obsession Dobsonian among them) and an outdoor theatre for regular stargazing sessions each weekend. This is a world-class Dark Sky Preserve and a World Heritage Site.

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