meteors – The Amazing Sky

December 2, 2020December 3, 2020

How to Photograph the Geminid Meteor Shower

The annual Geminid meteor shower peaks under ideal conditions this year, providing a great photo opportunity.

The Geminids is the best meteor shower of the year, under ideal conditions capable of producing rates of 80 to 120 meteors an hour, higher than the more widely observed Perseids in August. And this year conditions are ideal!

The Perseids get better PR because they occur in summer. For most northern observers the Geminids demand greater dedication and warm clothing to withstand the cool, if not bitterly cold night.

A Good Year for Geminids

While the Geminids occur every year, many years are beset by a bright Moon or poor timing. This year conditions couldn’t be better:

• The shower peaks on the night of December 13-14 right at New Moon, so there’s no interference from moonlight at any time on peak night.

• The shower peaks in the early evening of December 13 for North America, about 8 p.m. EST (5 p.m. PST). This produces a richer shower than if it peaked in the daytime hours, as it can in some years.

The two factors make this the best year for the Geminids since 2017 when I shot all the images here.

A composite of the 2017 Geminid meteor shower looking east to the radiant point. This is a stack of 40 images, each a 30-second exposure at f/2.5 with the Rokinon 14mm SP lens and Canon 6D MkII at ISO 6400. The images are the 40 frames with meteors out of 357 taken over 3.25 hours. The ground is a stack of 8 images, mean combined to smooth noise. The background base-image sky is from one exposure. The camera was on a fixed tripod, not tracking the sky. I rotated and moved each image in relation to the base image and around Polaris at upper left, in order to place each meteor at approximately the correct position in relation to the background stars, to preserve the effect of the meteors streaking from the radiant near Castor at centre.

What Settings to Use?

To capture the Geminids, as is true of any meteor shower, you need:

A good DSLR or mirrorless camera set to ISO 1600 to 6400.
A fast, wide-angle lens (14mm to 24mm) set to f/2.8 or wider, perhaps f/2. Slow f/4 to f/.6 kit zooms are not very suitable.
Exposures of 30 to 60 seconds each.
An intervalometer to fire the shutter automatically with no more than 1 second between exposures. As soon as one exposure ends and the shutter closes, the next exposure begins.
Take hundreds of images over as long a time period as you can on peak night.

Use an intervalometer to control the shutter speed, with the camera on Bulb. Set the interval to one second to minimize the time the shutter is closed.

Out of hundreds of images, a dozen or more should contain a meteor! You increase your chances by using:

A high ISO, so the meteor records in the brief second or two it appears.
A wide aperture, to again increase the light-gathering ability of the lens for those fainter meteors.
A wide-angle lens so you capture as much area of sky as possible.
Running two or more cameras aimed at different spots, perhaps to the east and south to maximize sky coverage.
A minimum interval between exposures. Increase the interval to more than a second and you know it’s during that “dark time” when the shutter is closed that the brightest meteor of the night will occur. Keep the shutter open as much as possible.

This sky chart looking east for December 13, 2020 shows the position of the radiant and the constellation of Gemini at about 7 p.m. local time. Orion is just rising in the east.

When to Shoot?

The radiant point of the shower meteors in Gemini rises in the early evening, so you might see some long, slow Earth-grazing meteors early in the night, streaking out of the east.

For Europe the peak of the shower occurs in the middle of the night of December 13/14.

For North America, despite the peak occurring in the early evening hours, meteors will be visible all night and will likely be best after your local midnight.

So wherever you are, start shooting as the night begins and keep shooting for as long as you and your camera can withstand the cold!

A single bright meteor from the Geminid meteor shower of December 2017, dropping toward the horizon in Ursa Major. Gemini itself and the radiant of the shower is at top centre. It is one frame from a 700-frame sequence for stacking and time-lapses. The ground is a mean stack of 8 frames to smooth noise. Exposures were 30 seconds at ISO 6400 with the Rokinon 14mm lens at f/2.5 and Canon 6D MkII.

Where to Go?

To take advantage of the moonless night, get away from urban light pollution to as dark a sky as you can. Preferably, put the major urban skyglow to the west or north.

While from brightly lit locations the very brightest meteors will show up, they are the rarest, so you’d be fortunate to capture one in a night of shooting from a city or town.

From a dark site, you can use longer exposures, wider apertures and higher ISOs to boost your chances of capturing more and fainter meteors. Plus the Milky Way will show up.

The Geminid meteor shower of December 13, 2017 in a view framing the winter Milky Way from Auriga (at top) to Puppis (at bottom) with Gemini itself, the radiant of the shower at left, and Orion at right. The view is looking southeast. This is a composite stack of one base image with the brightest meteor, then 20 other images layered in each with a meteor. The camera was not tracking the sky, so I rotated and moved each of the layered-in frames so that their stars mroe or less aligned with the base layer. The images for this composite were taken over 107 minutes, with 22 images containing meteors picked from 196 images in total over that time. Each exposure was 30 seconds with the Rokinon 14mm SP lens at f/2.5 and Canon 6D MkII at ISO 6400.

Where to Aim?

You can aim a camera any direction, even to the west.

But aiming east to frame the constellation of Gemini (marked by the twin stars Castor and Pollux) will include the radiant point, perhaps capturing the effect of meteors streaking away from that point, especially if you stack multiple images into one composite, as most of my images here are.

The Star Adventurer star tracker, on its optional equatorial wedge to aid precise polar alignment of its motorized rotation axis.

Using a Tracker

Using a star tracker such as the Sky-Watcher Star Adventurer shown here, makes it possible to obtain images with stars that remain untrailed even in 1- or 2-minute exposures. The sky remains framed the same through hours of shooting, making it much easier to align and stack the images for a multi-meteor composite.

A tracked composite showing the 2017 Geminid meteors streaking from the radiant point in Gemini at upper left. This is a stack of 43 exposures, each 1-minute with the 24mm Canon lens at f/2.5 and filter-modified Canon 5D MkII camera at ISO 6400, set fast to pick up the fainter meteors. These were 43 exposures with meteors (some with 2 or 3 per frame) out of 455 taken over 5 hours. The background sky comes from just one of the exposures. All the other frames are masked to show just the meteor.

However, a tracker requires accurate polar alignment of its rotation axis (check its instruction manual to learn how to do this) or else the images will gradually shift out of alignment through a long shoot. Using Photoshop’s Auto-Align feature or specialized stacking programs can bring frames back into registration. But good polar alignment is still necessary.

If you aim east you can frame a tracked set so the first images include the ground. The camera frame will move away from the ground as it tracks the rising sky.

A composite of the 2017 Geminid meteor shower, from the peak night of December 13, with the radiant in Gemini, at top, high overhead. So meteors appear to be raining down to the horizon. This was certainly the visual impression. This is a stack of 24 images, some with 2 or 3 meteors per frame, each a 30-second exposure at f/2.5 with the Rokinon 14mm SP lens and Canon 6D MkII at ISO 6400. The images are the 24 frames with meteors out of 171 taken over 94 minutes. The ground is a stack of 8 images, mean combined to smooth noise. The background base-image sky is from one exposure. The camera was on a fixed tripod, not tracking the sky.

Using a Tripod and Untracked Camera

The simpler method for shooting is to just use a camera (or two!) on a fixed tripod, and keep exposures under about 30 seconds to minimize star trailing. That might mean using a higher ISO than with tracked images, especially with slower lenses.

The work comes in post-processing, as stacking untracked images will produce a result with meteors streaking in many different orientation and locations, ruining the effect of meteors bursting from a single radiant.

To make it easier to stack untracked images, try to include Polaris in the field of the wide-angle lens, perhaps in the upper left corner. The sky rotates around Polaris, so it will form the easy-to-identify point around which you can manually rotate images in editing to bring them back into at least rough alignment.

Covering the steps to composite tracked and untracked meteor shower images is beyond the purview of this blog.

But I cover the process in multi-step tutorials in my How to Photograph and Process Nightscapes and Time-Lapses ebook, linked to above.

The images shown here were layered, masked and blended with those steps and are used as examples in the book’s tutorials.

A trio of Geminid meteors over the Chiricahua Mountains in southeast Arizona, with Orion and the winter stars setting. I shot this at the end of the night of December 13/14, 2017 with the rising waxing crescent Moon providing some ground illumination. This is a stack of one image for the ground and two fainter meteors, and another image with the bright meteor. The camera was on a Star Adventurer Mini tracker so the stars are not trailed, though the ground will be slightly blurred. All were 30-second exposures at f/2.8 with the 24mm Canon lens and filter-modified Canon 5D MkII at ISO 5000.

Keeping Warm

Keeping yourself warm is important. But your camera is going to get cold. It should work fine but its battery will die sooner than it would on a warm night. Check it every hour, and have spare, warm batteries ready to swap in when needed.

Lenses can frost up. The only way to prevent this is with low-voltage heater coils, such as the DewDestroyer from David Lane. It works very well. Other types are available on Amazon.

Good luck and happy meteor hunting!

December 23, 2017December 23, 2017

Chasing Meteors

Geminid Meteor Radiant in Gemini

Meteors were raining down the sky on the peak night of the Geminid meteor shower.

Back in August, when I wrote my column for the November-December issue of our Canadian magazine SkyNews, I noticed how good the circumstances were this year for the annual Geminid meteor shower. Normally one of the best showers of the year, if not the best, the Geminids were really going to perform in 2017.

The Moon was near new so its light would not interfere. For western North America, the peak of the shower was also timed for midnight on the night of December 13/14, just when the radiant of the shower was high in the sky.

Raining Geminid Meteors — The Geminids rain down the sky from the radiant in Gemini high overhead on peak night.

So in August when I saw the favourable combination of circumstances, I decided a meteor chase was in order. While the shower would be visible from home, Geminid peak night in December is often bitterly cold or cloudy at home in Alberta.

So I planned a trek to Arizona, for the shower and the winter sky.

While skies at home proved decent after all, it was still a chase worth making, with the shower visible under the perfectly clear and dry skies of southeast Arizona.

My chosen site was the Quailway Cottage near the Arizona Sky Village, the chosen dark sky site for many amateur astronomers, and at the foot of the Chiricahua Mountains. Skies are dark!

Sky Dust - Interplanetary and Interstellar — The Zodiacal Light (left) and Milky Way over the Chiricahuas.

The Zodiacal Light was brilliant in the southwest sky for several hours after sunset. A tough sighting at this time of year from most sites, this glow was obvious in the Arizona sky. It is sunlight reflecting off cometary dust particles in the inner solar system.

Geminid Meteor Shower in the Winter Milky Way — Geminids streaking from Gemini as the winter sky rises.

On the peak night, the visual impression was of meteors appearing at a rate of at least one a minute, if not more frequently.

Geminid Meteor Radiant in Gemini — A tracked composite looking up toward Orion and Gemini.

The images here are all composites of dozens of exposures taken over 2 to 5 hours, stacking many meteors on one frame. So they do provide an exaggerated record of the shower. Meteors weren’t filling the sky! But you certainly did not have to wait long for one to appear, making this one of the best meteor showers in many years.

Geminid Meteors over the Chiricahuas — Geminids falling over the Chiricahuas as Orion sets at the end of the peak night.

Most of the Geminids were of average brightness. I didn’t see, nor did the camera catch many very bright “bolides,” the really brilliant meteors that light up the ground.

Bright Geminid Meteor Descending — A bright Geminid pierces Ursa Major.

Nevertheless, this was a night to remember, and a fine way to end what has been a superlative year of stargazing, with a total solar eclipse, great auroras, and for me, a wonderful stay under southern skies on an April trip to Australia.

All the best of the season to you and your family and friends. Clear skies!

Here’s to 2018, which begins with a total eclipse of the Moon on January 31.

December 14, 2015

Meteor Shower over the VLA

Raining Meteors over the VLA Dishes

Meteors from the Geminid shower rain over the dishes of the VLA radio telescope.

Sunday night was a prime night for the annual Geminid meteor shower, one of the best of the year. To capture it, I traveled to the Plains of San Agustin in the high desert of New Mexico.

It’s there that the National Radio Astronomy Observatory operates the 27 dishes of the Very Large Array radio telescope, one of the most photogenic – and photographed – astronomical facilities in the world.

I set up at a viewing point near the entrance, to look northwest over the dishes, arrayed that night, and all season, in its most compact configuration, with all the dishes clustered closest together.

It was an active meteor shower! One particularly bright meteor left a persistent “train” – a smoke trail that lasted over 15 minutes. It creates the fuzzy cloud around the meteor at right. The bright bolide is on two frames, as the shutter closed then opened again as the meteor was still flying! So its bright streak got cut in two. Pity!

I shot with two cameras. The image here is from one, using a 35mm lens to shoot 334 frames over 3 hours. Each exposure was 32 seconds at f/2 and at ISO 3200.

I’ve taken about two dozen of the frames, the ones with meteors, and stacked them here, with the sky and ground coming from one frame. The camera was not tracking the sky.

Bands of natural airglow and clouds illuminated by the lights of Albuquerque to the north add colour to the sky.

I would have shot for longer than three hours, but this was a very cold night, with a brisk wind and temperatures below freezing. A snowstorm had even closed some roads the day before. Three hours was enough on the high plains of San Agustin this night.

May 25, 2014October 3, 2014

What Was That Glow in the Sky?

Here’s a time-lapse of the strange glow of light that moved across the northern sky on the night of the Camelopardalid meteor shower.

What I thought was an odd curtain of slow-moving, colourless aurora — and I’ve seen those before — has many people who also saw it suspecting it was a glow from a fuel dump from an orbiting satellite. Perhaps.

This short time-lapse of 22 frames covers about 22 minutes starting at 11:59 pm MDT on May 23 (as logged by the camera’s GPS). Each frame is a 60-second exposure taken at 2 second intervals. I’m playing them back at one frame per second.

The camera was on a tracking platform to follow the stars — thus the ground slowly rotates. This was one of the cameras I had operating the night of May 23-24 to capture meteors from the Camelopardalid meteor shower. The shower was a dud, but …

The most interesting thing my cameras did catch was this odd glow which started large and diffuse and then became more defined as it got smaller and moved off (or so it appears) to the north, then fades away. My photos (and I have it on frames from another camera), and photos taken by other observers across North America, show a faint satellite moving along south to north parallel to the cloud’s long axis. Is this the culprit that caused the cloud? If so, it would have to be very high to be seen from a wide range of longitudes – astronomers in Manitoba and Minnesota also saw and shot it.

But any fuel dumps I’ve seen always have clouds that start small and concentrated then become large and diffuse. This did the opposite.

I’ll await further analysis and explanation.

P.S.: You can watch a better version of the movie here at my Flickr site.

August 13, 2012August 13, 2012

Perseid Meteors and Planets over a Mountain Lake

It was quite a night, and a wonderful dawn. This was the scene at the end of a night of falling stars.

A trio of Perseid meteors zips down at left, while at right a trio of solar system worlds rises into the pre-dawn sky. The overexposed waning Moon is flanked by Jupiter above and Venus below. Jupiter shines near the Hyades star cluster and below the Pleiades cluster.

I took this shot (it is actually a composite of three shots, each with its own meteor) on the morning of Sunday, August 12 on the peak night of the annual Perseid meteor shower, widely publicized this year due to the lack of a Moon for most of the night, and the convenience of falling on a weekend. The scene is looking east over Lake Minnewanka in Banff National Park, Alberta, one of the few places in this part of the Rockies you can look east to a reasonably unobstructed sky.

Notice the glitter path on the water from not only the Moon but also Venus.