Astronomy author and photographer Alan Dyer presents amazing sky sights
Author: Alan Dyer
Alan Dyer is retired from a career as a writer and producer of science programs for science centres and planetariums. He is one of Canada’s best-known astronomy writers and serves as a contributing editor to SkyNews magazine. He also serves as a contributing editor to Sky and Telescope, writing frequent reviews of equipment.
He has co-authored several best selling guidebooks for amateur astronomers, including, with Terence Dickinson, "The Backyard Astronomer’s Guide." He recently published the multi-media eBook "How to Photograph and Process Nightscapes and Time-Lapses," available on the Apple iBooks Store.
Alan is a member of the exclusive The World at Night photography group (www.twanight.org).
As an amateur astronomer, his interests include astrophotography and deep-sky observing (he compiled some of the popular deep-sky observing lists in the annual RASC Observer's Handbook). Alan takes the opportunity as often as possible to visit the southern hemisphere to pursue both observing and photography under southern skies.
His other obsession, eclipse chasing, has taken him to every continent, chalking up 15 total solar eclipses. Asteroid 78434 is named for him.
Prospects looked bleak for seeing the January 31 total eclipse of the Moon. A little planning, a chase, and a lot of luck made it possible.
A mid-winter eclipse doesn’t bode well. Especially one in the cold dawn hours. Skies could be cloudy. Or, if they are clear, temperatures could be -25° C.
I managed to pull this one off, not just seeing the eclipse of the Moon, but getting a few photos.
The secret was in planning, using some helpful apps …
Because this eclipse was occurring before dawn for western North America the eclipsed Moon was going to be in the west, setting.
To plan any shoot the first app I turn to is the desktop planetarium program Starry Night™.
Shown above, the program simulates the eclipse with the correct timing, accurate appearance, and location in the sky at your site. You can set up indicators for the fields of various lenses, to help you pick a lens. The yellow box shows the field of view of a 50mm lens on my full-frame camera, essential information for framing the scene.
With that information in mind, the plan was to shoot the Moon over the Rocky Mountains, which lie along the western border of Alberta.
The original plan was a site in Banff on the Bow Valley Parkway looking west toward the peaks of the Divide.
But then the next critical information was the weather.
Not good! Home on the prairies was not an option. While Banff looked OK, the best prospects were from farther south in the Crowsnest Pass area of Alberta, as marked. So a chase was in order, involving a half-day drive south.
But what actual site was going to be useful? Where could I set up for the shot I wanted?
I needed a spot off a main highway but drivable to, and with no trees in the way. I did not know the area, but Allison Road looked like a possibility.
The TPE app shows the direction to the Sun and Moon to help plan images by day. And in its night mode it can show where the Milky Way is. Here, the thin blue line is showing the direction to the Moon during totality, showing it to the south of Mt. Tecumseh. I wanted the Moon over the mountains, but not behind a mountain!
With a possible site picked out, it was time to take a virtual drive with Google Earth.
The background map TPE uses is from Google Earth. But the actual Google Earth app also offers the option of a Street View for many locations.
Above is its view from along Allison Road, on the nice summer day when the Google camera car made the drive. But at least this confirms there are no obstructions or ugly elements to spoil the scene, or trees to block the view.
But there’s nothing like being there to be sure. It looks a little different in winter!
After driving down to the Crowsnest Pass the morning before, the first order of the day upon arrival was to go to the site before it got dark, to see if it was usable.
I used the mobile app Theodolite to take images (above) that superimpose the altitude and azimuth (direction) where the camera was aimed. It confirms the direction where the Moon will be is in open sky to the left of Tecumseh peak. And the on-site inspection shows I can park there!
There is one more new and very powerful app that provides another level of planning. From The Photographer’s Ephemeris, you can hand off your position to a companion mobile app (for iOS only) called TPE 3D …
It provides elevation maps and places you on site, with the actual skyline around you drawn in. And with the Moon and stars in the sky at their correct positions.
While it doesn’t simulate the actual eclipse, it sure shows an accurate sky … and what you’ll frame with your lens with the actual skyline in place.
Compare the simulation, above, to the real thing, below:
Zooming out with TPE 3D provides this preview of a panorama I hoped to take.
It shows Cassiopeia (the W of stars at right) over the iconic Crowsnest Mountain, and the stars of Gemini setting to the right of Tecumseh.
Here’s the real thing, in an even wider 180° view sweeping from south to north. Again, just as predicted!
Between the weather predictions – which proved spot on – and the geographical and astronomical planning apps – which were deadly accurate – we now have incredible tools to make it easier to plan the shot.
If only we could control the clouds! As it was, the Moon was in and out of clouds throughout the 70 minutes of totality. But I was happy to just get a look, let alone a photo.
The next total lunar eclipse is in six months, on July 27, 2018, but in an event visible only from the eastern hemisphere.
The next TLE for North America is a more convenient evening event on January 20, 2019. That will be another winter eclipse requiring careful planning!
I present a new 4-minute music video (in 4K resolution) featuring time-lapses of the Milky Way.
One of the most amazing sights is the Milky Way slowly moving across the sky. From Canada we see the brightest part of the Milky Way, its core region in Sagittarius and Scorpius moving across the souther horizon in summer.
But from the southern hemisphere, the galactic core rises dramatically and climbs directly overhead, providing a jaw-dropping view of our edge-on Galaxy stretching across the sky. It is a sight all stargazers should see.
I shot the time-lapses from Alberta, Canada and from Australia, mostly in 2016 and 2017.
I include a still-image mosaic of the Milky Way from Aquila to Crux shot in Chile in 2011.
Do watch in 4K if you can! And in Full-Screen mode.
Locations include Writing-on-Stone and Police Outpost Provincial Parks, and Banff and Jasper National Parks in Alberta.
In Australia I shot from the Victoria coast and from inland in New South Wales near Coonabarabran, with some scenes from the annual OzSky Star Safari held each April.
On a very clear night, Orion shines over the skyline of Calgary.
As I live in the country, it’s not often I shoot the stars from urban sites, and certainly not from downtown Calgary. But the combination of a clear night and a speaking commitment in Calgary provided a chance to see what was possible under ideal conditions.
The lead image is real – I did not paste an image of the sky taken at some other time or place over the skyline image.
However, the sky image is a longer exposure (10 seconds) than the ground (3 seconds) in order to bring out the stars better, while keeping the city lights under control with no overexposure. So it is sort of a high dynamic range blend.
The other factor that helped reveal stars as faint as shown here (fainter than what the naked eye can see) is the use of a light pollution reduction filter (a NISI Natural Night filter) to penetrate the yellow sky glow and provide a more pleasing colour to the sky.
Earlier in the night, during twilight when urban light pollution is not so much of an issue, I shot the waxing crescent Moon setting over the skyline.
This is a panorama image made from high dynamic range blends of various exposures, to again accommodate the large range in brightness in the scene. But I did not use the NISI filter here.
These images demonstrate how you can get fine astronomy images even from urban sites, with planning and timing.
To that end, I used my favourite app, The Photographer’s Ephemeris, to determine where the sky elements would be as seen from a couple of viewpoints over the city that I’ve used in the past.
The blue spheres in the left image of TPE in its Night mode represent the Milky Way. That chart also shows the direction toward Orion over the city core.
The right image of TPE in its Day mode shows the position of the Moon at 6 pm that evening, again showing it to the left of the urban core.
Other apps are capable of providing the same information, but I like TPE for its ease of use.
The first total lunar eclipse in 2.5 years provides lots of opportunities for some great photos.
On the morning of January 31, before sunrise for North America, the Full Moon passes through the umbral shadow of the Earth, creating the first total eclipse of the Moon since September 27, 2015.
The pre-dawn event provides many photo opportunities. Here’s my summary of tips and techniques for capturing the eclipsed Moon.
But First … What is a Lunar Eclipse?
As the animation (courtesy NASA/Goddard Space Flight Center) shows, an eclipse of the Moon occurs when the Full Moon (and they can happen only when the Moon is exactly full) travels through the shadow of the Earth.
The Moon does so at least two times a year, though often not as a total eclipse, one where the entire disk of the Moon is engulfed by the umbra.
When the Moon is within only the outer penumbral shadow we see very little effect, with a barely perceptible darkening of the Moon, if that. I don’t even list the times below for the start and end of the penumbral phases.
It’s only when the Moon begins to enter the central umbral shadow that we see an obvious effect. That’s when the partial eclipse begins, and we see a dark bite appear on the left edge of the Moon. The shadow appears to creep across the Moon to darken more of its disk. While it looks like the shadow is moving across the Moon, it is really the Moon moving into, then out of, the umbral shadow that causes the eclipse.
At this eclipse the partial phases last about an hour before and after totality.
Once the Moon is completely immersed in the umbra, totality begins, and lasts 77 minutes at this eclipse, a generous length. However, in North America, only sites in the western half of the continent get to see all or most of totality.
Where is the Eclipse?
As the chart above shows, the Pacific area including Hawaii, Australia, and eastern Asia can see the entire eclipse with the Moon high in the evening or midnight sky.
Most of North America (my tips are aimed at North American photographers) can see at least some part of this eclipse.
From the eastern half of the continent the Moon sets at sunrise during either totality (from the central areas of North America), or during the first partial phases (from eastern North America). Those in the east can take advantage of interesting photo opportunities by capturing the partially eclipsed Moon setting in the west in the dawn twilight.
However, the most dramatic images of a deep red Moon in the western sky, such as above, will be possible only from the west. And even then, the further north and west you live, the better your view.
Even from the southwestern United States the Moon sets just after the end of totality, requiring a site with a low and clear horizon to the west in order to see the whole event.
I live in Alberta, Canada, and the diagrams I provide here are for my area, where the Moon sets during the final partial phase. I offer them as examples of the kinds of planning you can do to ensure great photos. But exactly where the Moon will be during totality, and where and when it will set on your horizon, will depend on your location.
The latter two apps present the sightlines toward the Moon overlaid on a map of your location, to help you plan where to be to shoot the eclipsed Moon setting behind a suitable foreground.
When is the Eclipse?
While where the Moon is in your sky depends on your site, the various eclipse events happen at the same time for everyone, with differences in hour due only to the time zone you are in.
Here are the times for the start and end of the partial and total phases.
Note that all times are A.M., in the early morning, before sunrise, on January 31. Go out at 6 P.M. on the evening of January 31 and you’ll be 12 hours too late. You missed it!
All times are A.M. on January 31. “—“ means the event is not visible; the Moon has set.
The time of moonset at your site will vary with your location. Use planning apps to calculate your local moonset time.
Picking a Site
No matter where you are in North America you want a site with a good view to the west and northwest, preferably with a clear view of a relatively unobstructed but photogenic horizon.
While having an eclipse occur at dawn (or at dusk) does limit the amount of eclipse we can see, it has the benefit of providing many more photo opportunities of the eclipsed Moon above a scenic landscape or foreground element.
From eastern North America you will have to be content with images of the partially eclipsed Moon setting, similar to the image above of a rising partially-eclipsed Moon.
From the centre of the continent, where the Moon sets during totality, the dim, reddened Moon is likely to disappear into the brightening sky. Remember, when the Moon is full it sets just as the Sun rises. So shots of a red Moon right on the horizon aren’t likely to be possible. The Moon will be too dim and the sky too bright.
From sites in the west, the Moon will set either just at the end of totality or shortly afterwards, making the Moon brighter and more obvious in the sunrise sky, as the foreground in the west lights up with red light from the Sun rising in the east.
It is that same red sunlight filtered by our atmosphere that continues on into our planet’s shadow and lights the Moon red during totality.
Picking a Technique
Lunar eclipses lend themselves to a wide range of techniques, from a simple camera on a tripod, to a telescope on a tracking mount following the sky.
What you use depends not only on the gear you have on hand, but also on your site. It might not be practical to set up loads of gear at a scenic site you have to trek into — especially when you have to set up in the wee hours of a cold winter morning.
You could set up earlier that night on January 30, but only if your site is safe enough to leave the gear unattended while you sleep.
Keep it simple!
Option 1: Simple Camera-on-Tripod
The easiest method is to take single shots with a moderate wide-angle or normal lens with the camera on a fixed tripod. No fancy trackers are needed here.
If the sky is bright with twilight, you might be able to meter the scene and use Auto exposure.
But earlier in the night, with the Moon in a darker sky, as I show above, use Manual exposure and try settings of 1 to 10 seconds at f/2.8 to f/4 at ISO 400 to 1600. That’s a wide range, to be sure, but it will vary a lot depending on when you shoot and where you are, factors that will affect how bright the sky is at your site. Just shoot, check, and adjust.
Option 2: Advanced Camera-on-Tripod
A more advanced method is to compose the scene so the lens frames the entire path of the Moon from the start of the partial eclipse until moonset.
As shown above, that will take at least a 35mm lens on a full frame camera, or 20mm lens on a cropped frame camera.
Take exposures every 15 to 30 seconds if you want to turn the set into a time-lapse movie. But a still-image composite with the lunar disks well separated will need shots only every 5 to 10 minutes.
Such a composite takes good planning and proper exposures to pull off, but will be true to the scene, with the lunar disk and its motion shown to the correct scale as it was in the sky. That’s in stark contrast to the flurry of ugly “faked” composites that will appear on the web by the end of February 1, ones with huge telephoto Moons pasted willy-nilly onto a wide-angle sky. Don’t do it!
Exposures for any lunar eclipse are tricky, whether you are shooting closeups or wide-angles, because the Moon and sky change so much in brightness.
For wide-angle composites, you can expose just for the bright lunar disk and let the sky go dark. Exposures for just the Moon will range from very short (about 1/500th second at ISO 100) for the partials, to 1 to 2 seconds at ISO 400 for the totals, then shorter again (1/15 to 1/2 second at ISO 400) for the end shots in twilight when the Moon and sky may be similar in brightness. That’ll take constant monitoring and adjusting throughout the shoot.
As I did below, you’d then composite and layer the well-exposed disks into another background image exposed longer for the sky, likely shot in twilight. To maintain the correct relative locations of the lunar disks and foreground, the camera cannot move.
That technique works best if it’s just a still image you are after, such as below.
The above image is a composite of the April 4, 2015 total lunar eclipse from Monument Valley, Utah. That eclipse occurred under similar circumstances as this month’s eclipse, with the eclipse underway as the Moon set in the west at sunrise.
By comparison, the composite here is made of a few selected frames out of hundreds I took at 15-second intervals, and with each frame exposed for the sky, for use in a time-lapse movie. In this case, the Moon became overexposed at the end as it emerged from the umbra.
Indeed, if it’s a time-lapse movie you want (see the video linked to below), then each frame will have to be exposed well enough to show the sky and landscape.
While this method will overexpose the partially-eclipsed Moon, the Moon will darken and become better exposed throughout totality when the same long exposure for the reddened Moon might also work for the sky, to pick up stars. Exposures will have to shorten again as the sky brightens with twilight.
Again, constant baby-sitting and adjusting the camera will be needed. So if it’s cold where you are prepare for a frigid multi-hour shoot. I doubt you’ll be able to leave the camera on Auto exposure to run on its own, not until at least bright twilight begins.
Option 3: Telephoto Close-Ups
The Moon is surprisingly small (only 1/2-degree across) and needs a lot of focal length to do it justice.
For an “in-your-face” close-up of the eclipse you’ll need a 300mm to 800mm (!) lens. Unfortunately, the Moon and sky are moving and any exposures over 1 to 2 seconds (required during totality) will blur the Moon badly if its disk is large on the frame.
If you don’t have a tracking mount, one solution is to keep the Moon’s disk small (using no more than a fast f/2.8 200mm lens) and exposures short by using a high ISO speed.
Or plan to shoot with a telephoto only when the Moon is low in the sky, as I did above, when you can include the horizon which you would want to be sharp anyway. Framing the Moon and horizon won’t need a super telephoto.
The sky will then also be brighter and require short exposures that don’t need to be tracked. However, how bright and obvious the Moon will be will again depend on your location. This may or may not be a practical option, certainly not if the Moon is setting during mid-totality where you are.
Option 4: Tracked Telescopic Close-Ups
If you have a mount that can be polar aligned to track the sky, then more options are open to you.
You can use a telescope mount or one of the compact and portable trackers, such as the Sky-Watcher Star Adventurer or iOptron Sky Tracker units. While these latter units work great, you are best to keep the payload weight down and your lens size under 300mm.
That’s just fine for this eclipse, as you really don’t need a frame-filling Moon. The reason is that the Moon will appear about 4 degrees away from the bright star cluster called the Beehive, or Messier 44, in Cancer. As shown above, a 200mm to 300mm lens will frame this unique pairing well.
Even so, exposures to show the cluster properly might have to be long enough that the Moon overexposes, even at mid-totality. If so, take different exposures for the Moon and stars and composite them later, as I did below.
If you do want to shoot with more focal length, a monster telephoto lens will work, but a small telescope such as an 80mm aperture f/6 to f/7 refractor will provide enough focal length and image size at much lower cost. But either way, the lens or telescope should be mounted on a solid equatorial telescope mount, and polar aligned to track the sky.
For the sharpest lunar disks, use the Lunar tracking rate.
Exposures will vary from as short as 1/500th second at ISO 100 to 200 for the barely eclipsed Moon, to 4 to 16 seconds at f/6 to f/8 and at ISO 400 to 1600 for the Moon at mid-totality.
As I did above, during the deep partial phases shoot both long exposures for the red umbra and short exposures for the bright part of the Moon not yet in the umbra. Merge those later with High Dynamic Range (HDR) techniques and software, or with luminosity masks.
Even if you’re not sure how to do this now, shoot all the required exposures anyway so you’ll have them when your processing skills improve.
Option 5: Time-Lapse Close-Ups
With a tracking telescope you could fire shots every 30 seconds or so, and then assemble them into a time-lapse movie.
But as with wide-angle time-lapses, that will take constant attention to gradually and smoothly shift exposures, ideally by 1/3rd-stop increments every few shots during the partial and total phases.
If you track at the lunar rate, as I did in the still image below and in the music video linked to at bottom, the Moon will stay centred while it drifts though the stars.
Track at the sidereal rate and the stars will stay more or less fixed while the Moon drifts through the frame from right to left (west to east). But that takes even more careful planning to position the Moon correctly at the start of the sequence so it remains “in frame” for the duration of the eclipse and ends up where you want at the end, which will occur with the Moon low in a bright sky.
Again, planetarium software such as Starry Night, which can be set to display a camera frame, is essential to plan the shoot.
Either way, do take care to accurately polar align your mount, or you’ll be confronted with the monumental task of having to manually align hundreds of images later. Trust me, I know!
I would consider the telescopic time-lapse method the most challenging of techniques.
Considering the hour of the night and the likely cold temperatures, your best plan might be to keep it simple. It’s what I plan to do. I’ll be happy to get a few good wide-angle still images, and perhaps a tracked telephoto close-up of the Moon and Beehive as a bonus.
While there is another total lunar eclipse (TLE) in six months on July 27/28, it is not visible at all from North America.
Our next TLE occurs 12 Full Moons, or one lunar year from now, on the night of January 20/21, 2019, when all of North America gets to watch totality at a more reasonable hour, though perhaps not at a more reasonable temperature.
I leave you with a music video of the last TLE, on September 27, 2015 that incorporates still and time-lapse sequences shot using all of the above methods.
Mars and Jupiter are meeting up in the morning sky. Soon they’ll be joined by the Moon.
Here’s a heads up for one of the best planet conjunctions of the year. Mars and Jupiter are now close together in the dawn sky to the south, and getting closer!
Above is the actual view on the morning of January 4, with Jupiter the brightest of a trio of objects. Mars is reddish and in the middle. The object at right is the star Alpha Librae, also known as Zubenelgenubi in Libra.
As shown in the simulation above, on the morning of January 6 Mars and Jupiter will be only 1/3rd of a degree apart (20 arc minutes), so close that dimmer Mars might not be obvious to the naked eye next to bright Jupiter. But use binoculars to show the planet pair.
The next morning, on January 7, they will appear almost as close, as Jupiter climbs higher past Mars.
As shown here, on the morning of January 11 the waning crescent Moon will sit only 4 degrees from the planet pair, with all three worlds gathered close enough for binoculars to frame the scene.
With sunrise coming late on winter mornings, it doesn’t take an early rise to take in the dawn scene. Make a note to take a look about 6:30 to 7:00 a.m. over the next week.
POSTSCRIPT added January 6:
Here’s the real scene from the morning of January 6, with Mars and Jupiter just 16 arc minutes apart, very close but still easy to distinguish with the naked eye. Jupiter did not overwhelm Mars.
New Year’s Day proved to be a busy one for sky sights from home in southern Alberta.
Clear skies and warming temperatures allowed me to capture a trio of sights on January 1: Mercury in the morning, a unique mirage called the Fata Morgana in the afternoon, and the rising Full Moon in the evening.
On January 1 elusive Mercury was at its greatest elongation away from the Sun in the morning sky. This placed it as high as it can get above the horizon, though that’s not high at all at the best of times.
I captured Mercury before dawn as a bright star in the colourful twilight, using a telephoto lens to frame the scene more closely.
At this time the temperature outside was still about -24° C, as a cold snap that had plunged the prairies into frigid air for the last week still held its grip.
But by the afternoon, warmer air was drifting in from the west, in a Chinook flow from the Rockies.
As evidence of the change, the air exhibited a form of mirage called the Fata Morgana, named after the sorceress Morgan le Fay of Arthurian legend. The illusion of castles in the air was thought to be a spell cast by her to lure sailors to their doom.
The mirage produced the illusion of bodies of water in the distance, plus distorted, elongated forms of wind turbines and farm buildings on the horizon. The cause is the refraction of light by layers of warm air aloft, above cold air near the ground.
By evening the mirage effect was still in place, producing a wonderful moonrise with the Full Moon writhing and rippling as it rose through the temperature inversion.
As the lead image at top shows, at moments the top of the disk had a green rim (almost a distinct green flash), while the bottom was tinted red.
Here’s a short time-lapse video of the scene, shot through a small telescope. The lead image above and below is a composite of four of the frames from this movie.
This was also the largest and closest Full Moon of the year, what has become popularly called a “supermoon,” but more correctly called a perigean Full Moon.
A lunar cycle from now, at the next Full Moon, the Moon undergoes a total eclipse in the dawn hours of January 31 for western North America. This will be another misnamed Moon, a “blue Moon,” the label for the second Full Moon in a calendar month.
And some will also be calling it a “supermoon,” as it also occurs close to perigee – the closest point of the Moon to Earth in its monthly orbit – but not as close a perigee as it was at on January 1.
So it will be less than super, but it will nevertheless be spectacular as the Full “blue” Moon turns red as it travels through Earth’s shadow.
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.
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 Cottagenear the Arizona Sky Village, the chosen dark sky site for many amateur astronomers, and at the foot of the Chiricahua Mountains. Skies are dark!
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.
On the peak night, the visual impression was of meteors appearing at a rate of at least one a minute, if not more frequently.
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.
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.
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.