Exploring the Earth and Sky of the West

Posts tagged “astrophotography

Comet NEOWISE: Update and Photos

A comet and its tail appears in the pre-dawn sky with a mountain range and valley fog in the foreground

Comet C/2020 F3 (NEOWISE) continues to put on a stellar show for skywatchers in the northern hemisphere. Over the past week, the comet has moved into the evening sky, making a trip out to see it somewhat more palatable than it was when I first highlighted the comet 11 days ago. Last week, I had the pleasure of viewing the comet twice in one night while camping on the east flank of Mt. St. Helens. High clouds prevented a great view at sunset, but had mostly cleared just four hours later when the comet rose again in the northeast. Just below and to the left of the comet was the distant cone of Mt. Rainier. Low clouds in the river valleys below us made for a spectacular view:

A comet and its tail appears in the pre-dawn sky with a mountain range and valley fog in the foreground

Comet NEOWISE rises over the distant cone of Mt. Rainier as seen from Mt. St. Helens.

A comet and its tail appears in the pre-dawn sky with a mountain range and valley fog in the foreground

Comet NEOWISE on the morning of July 13, 2020.

Unfortunately, the comet has dimmed noticeably over the past few evenings. While we still have a few days until its closest approach to Earth, the comet has receded from the Sun enough that its activity is likely beginning to wane. The next few nights will likely provide the final chance to see this comet and its tail with the unaided eye (until it returns ~6,800 years from now that is!) The waxing moon will begin to interfere by later this week and by the time the moon leaves the evening sky a few weeks from now, the comet will likely have faded from naked eye visibility. To see it, look northwest 1-2 hours after sunset. The comet will appear a little below the bowl of the Big Dipper, and is far enough north now that viewing is significantly better from more northerly locations. More details on spotting the comet can be found here: https://earthsky.org/space/how-to-see-comet-c2020-f3-neowise

Good luck!


Sunset to Sunrise at Bryce Canyon

Sunrise at Bryce Canyon lights up rock formations

Sunrise light illuminates rock formations at Bryce Canyon National Park

Sunset, nighttime, and sunrise are probably the three most exciting times for photography, and I got to hit all three on a quick trip to Bryce Canyon National Park this past weekend. I experienced a brilliant sunset, hiked into the Bryce amphitheater by moonlight, joined the masses for sunrise, and was back in my own home less than 24 hours after walking out the front door. I feel incredibly lucky to live close enough to such wonders that trips like this are possible. This impromptu trip was facilitated by the unseasonable heat wave currently gripping Southern Utah. On Sunday night, the overnight low at Bryce barely dropped below freezing (about 15 degrees above average for this time of year) making a quick camping trip a reasonable proposition.

This was actually my first trip to Bryce Canyon in the winter months. While snow has made itself scarce in Southern Utah the last few weeks, and most of the snow had melted away from the hoodoos, there was still quite a bit of the white stuff left on the north facing slopes, making for a gorgeous complement to the ruddy hoodoo hues.

Before hitting the trail for sunset, I took time to drive out to some of the overlooks at the south end of the park. Bryce Canyon may be known for hoodoo hiking, but south of the main amphitheater lie some truly mind-blowing views of the Grand Staircase and Colorado Plateau. The Paunsaugunt Plateau on which Bryce Canyon sits rises to elevations of more than 9,000 feet, allowing commanding views of the surrounding terrain. I truly believe that the view from Yovimpa Point is one of the best on the planet (albeit difficult to photograph), with a viewshed stretching from the North Rim of the Grand Canyon, to Navajo Mountain and Lake Powell near Page, to the 11,000 monolith of Powell Point and the Aquarius Plateau.

Panoramic view from Farview Point, Bryce Canyon National Park

Looking east from Farview Point. Note how all the snow has melted from the south facing slopes, but much remains on the north aspects

As the sun dropped lower, I headed out on the trail to Tower Bridge. In hindsight I should have taken a picture of the mud, but I guess I was too preoccupied trying not to lose a boot to the bright orange morass. With winter freeze/thaw cycles still in full swing, the trails were all littered with fragments of rock fallen from the cliffs and hoodoos above, a good reminder of the primary process responsible for creating this unique landscape.

Hoodoos, fins, and walls at Bryce Canyon National Park

Late afternoon sun illuminates hoodoos, fins, and walls along the trail to Tower Bridge at Bryce Canyon National Park

Bristlecone Pine and snow at Bryce Canyon National Park

A scraggly Bristlecone Pine (Pinus longaeva) between residual snow patches along the trail to Tower Bridge

View of Powell Point from Bryce Canyon National Park

A classic Bryce view at sunset: looking northeast towards Powell Point (10,188′) and the Aquarius Plateau

Moonrise over Powell Point and the Sinking Ship, Bryce Canyon National Park

The full moon rising over Powell Point and the Sinking Ship

My visit happened to coincide with a full moon so Milky Way photographs were out of the question. The light made it quite easy to navigate the trails looking for interesting photo opportunities. In several hours of wandering around the amphitheater, I don’t think I turned my headlamp on once. It was seriously bright out there.

Stars and constellations above Bryce Canyon

The constellation Orion hovers over the hoodoos of Bryce Canyon National Park

Star trails above Thor's Hammer, Bryce Canyon National Park

Star trails above Thor’s Hammer, Bryce Canyon National Park

With the photo above, I was hoping for longer star trails but after just half an hour, my camera battery died. After scrambling to replace it, I discovered that someone (who shall remain unnamed…) had forgotten to charge their spare camera battery. With only enough power on the spare for a few dozen more exposures, I decided to pack it in for the evening rather than continuing with the star trials, and save my remaining juice for sunrise…which turned out to be a good call.

While Bryce is beautiful at any time of day, sunrise is truly the golden hour. Because most of the amphitheater faces east, sunlight creates so many interesting light patterns among the hoodoos that one almost can’t decide where to look. This was the 2nd morning since the switch to daylight savings, and the crowds reflected the fact that sunrise was now at a quite palatable 7:30 AM.

Limber Pine in sunrise light at Bryce Canyon National Park

A famous and tenacious Limber Pine (Pinus flexilus) at Sunrise Point observes yet another sunrise

Hoodoos at sunrise, Bryce Canyon National Park

Hoodoos at sunrise, Bryce Canyon National Park

People watching sunrise at Bryce Canyon National Park

The crowds assemble for sunrise at Bryce Canyon National Park


Top 10 from 2014

As in past years, with the coming of the New Year I decided to take a look back at all the photos I took in 2014 and select some of my favorites to share with you here on the blog. Between finishing graduate school (yippee!) and making a permanent (for now) move from the Pacific Northwest to Colorado, I had less time to devote to photography than in previous years. Nevertheless, picking out my favorite photos was difficult as usual and a good reminder that I was fortunate to have the opportunity to experience and photograph a a number of new places in the past year, from the coasts of Olympic National Park to remote alpine basins in the Rocky Mountains.

Without further ado, here are my ten favorite photos from 2014 in chronological order. Here’s wishing you all a healthy and happy new year!

1. Tulip Fields at Sunset, Skagit Valley Tulip Festival, Washington

Filed at Skagit Valley Tulip Festival

Held annually in April, the Skagit Valley Tulip Festival is a must see for any spring visitor to NW Washington, photography buff or not. On weekends, especially sunny ones, the tulip fields that spread out across the Skagit Valley about an hour north of Seattle are overrun, making photography difficult. Fortunately, I lived only about a half hour away and was able to visit on a less-busy weekday evening in order to photograph the picture-perfect bulbs in their prime and without the crowds.

2. American Bison, Yellowstone National Park

A solitary bison in Yellowstone National Park

I’m going to come clean: this is the only photo on this list taken from the confines of my car! I was departing Yellowstone at the end of an impromptu day-trip to the park while attending a geology conference in Bozeman when I spotted this solitary bison along the road. Fortunately, no vehicles were coming up behind me so I was able to grab my camera and capture the glow of the late afternoon sunlight and the diffuse reflection of the bison in a pool of late-season snow melt.

3. Milky Way, Airglow, and Light Pollution from Hurricane Ridge, Olympic National Park, Washington

Milky Way and airglow from Hurricane Ridge, Olympic National Park

Living near Seattle doesn’t exactly do wonders for one’s chances of observing rare celestial events. What’s one to do? Get above the clouds of course! I was thrilled to be visiting Olympic National Park during the peak of the Cameleopardalids meteor shower in May. In order to get an unobstructed view, we made the drive up to Hurricane Ridge just before midnight in hopes of catching some meteors. As you may recall, the meteor shower fizzled spectacularly but all was not lost: I was able to capture this panorama of the summer Milky Way emerging from the disgusting Seattle light dome (over 50 miles away as the crow flies) as it rose in the west. Despite the light pollution, I also managed to capture the ghostly green glow of an atmospheric phenomenon known as “airglow” (which I’ve written about previously) and the low lying clouds smothering the Elwah River Valley several thousand feet below.

4. Giant Green Anemone (Anthopleura xanthogrammica), Olympic National Park

Close-up of a Giant Green Anemone in Olympic National Park

I developed a slight infatuation with seeking out and photographing marine life during my two years in Western Washington. Timing trips to the coast with some of the lowest tides of the year helped me discover a wide variety of anemones, nudibranchs, sea stars, urchins, and much more. Anemones were perhaps my favorite group to photograph, their neon-colored and delicate tentacles waving back and forth in the surf.

5. Panorama from Hole-in-the-Wall, Rialto Beach, Olympic National Park

Panorama from top of Hole-in-the-Wall, Rialto Beach, Olympic National Park

Rialto Beach is one of the most popular spots in Olympic National Park…for obvious reasons. The short 2-mile hike to Hole-in-the-Wall was one of my favorite experiences this year. Once reaching the famous rock formation, we found an nearly entirely overgrown path that led us up to a viewpoint on the crest of Hole-in-the-Wall, getting us away from the surprisingly scant Memorial Day crowds and immersing us in expansive views of sea stacks, rocks, and islands along the Olympic coast.

6. Summer Wildflowers at Ice Lake, San Juan Mountains, Colorado

Wildflowers at Ice Lake

Despite my ravings about Rialto Beach in the previous photo, our trek to Ice Lake in the San Juan Mountains of Colorado was hands down my favorite hike of the year, and one of my most memorable ever. My only regret about this day was that we weren’t prepared for an overnight (or at least a hike back to the car in the dark!), which means I missed out on what was surely a epic sunset from the basin. Click the link above for more photos of this spectacular place.

7. Ice Lake Panorama, San Juan Mountains, Colorado

Panorama of Ice Lake, San Juan Mountains

Did I mention Ice Lake was spectacular? It snagged two of the coveted spots on the top 10 list. That means you have to go.

8. Circumpolar Star Trails from Escalante Canyon, Colorado

Star Trails from Escalante Canyon

Photographing star trails is a bit more complex in the digital age than it was with film. This was only my second legitimate attempt, but I was happy with how it turned out. Extremely long single exposures suffer from a variety of maladies so this photo is actually a composite of over 100 consecutive 30″ exposures (for the stars), and one 3″ exposure for the foreground juniper which I illuminated with a headlamp. In post-processing, I had the pleasure of removing more than a dozen aircraft which passed overhead during the hour or so it took to gather the series of exposures. I elected not to remove the two meteors (astronomical objects flashing through the frame are fine by me) but I’m looking forward to doing some more star trail photography from places not on major transcontinental flight paths.

9. Exclamation Point, Black Canyon of the Gunnison, Colorado

Black Canyon of the Gunnison from Excalmation Point

I love this photo because it exemplifies how the canyon got its name. Despite being taken at 10 o’clock in the morning, the narrow gorge carved into dark Precambrian metamorphic rocks remained shrouded in shadow, while its surroundings (and portions of the canyon bottom) are basking in the bright, mid-morning sunshine. This photo was taken from an overlook on the remote and seldom visited North Rim of Black Canyon, which offers the most spectacular views into the narrowest portion of this amazing gorge and is truly worth the effort to visit.

10. Waving Aspen and Grasses, Rocky Mountain National Park, Colorado

Waving aspen tree, Rocky Mountain National Park

I didn’t purchase any new camera gear this year, but was the recipient of a 9-stop neutral density filter for my birthday, a filter I’ve been wanting to experiment with for a while now. That filter allowed me to take this photo, a 30″ exposure at f/22 in broad daylight, and capture the motion of a colorful aspen and meadow grasses waving in the wind on a autumn day in Rocky Mountain National Park.

 

 

 


Photographing the Night Sky from Colorado

Colorado is a great place for those of you who, like me, are perpetually torn between looking up and looking down. Colorado’s spectacular geologic landscapes keep me occupied during the day, but at night a whole different world opens up overhead. Colorado is a great place to look at and photograph the night sky for several reasons:

  • It’s relatively dark. With the exception of the Front Range megalopolis (where I now live), there are few egregious sources of light pollution, especially when compared to just about every state east of here.
  • It has the highest average elevation of any state. This is important because looking through the Earth’s atmosphere at the stars is like looking through a glass of water at a friend sitting next to you. The higher you go, the thinner the atmosphere becomes, and the better and steadier your view of the night sky.
  • It has good weather. Clear skies can be found regularly throughout the year, unlike in the black hole of astronomy known as the Pacific Northwest.
  • It has lots of public land where you can theoretically spend all night outside taking photos without fear of getting shot.

I spent a good chunk of this past summer honing my astrophotography skills and if you’ve never tried your hand at it, I encourage you to give it a try. It has certainly made me a better all-around photographer. First and foremost, astrophotography is an exercise in patience, both at the camera itself and then in front of the computer afterwards, and patience is a valuable virtue in all aspects of photography. Ironically, as comfortable as I am outside under the stars, astrophotography actually pushes out of my comfort zone photographically. Apart from minor brightness or contrast adjustments and cropping, I tend to eschew significant post-processing of my photos. When photographing the night sky though, some quality alone time with Photoshop and Lightroom is pretty much a necessity in order to get something that looks good.

Milky Way stretching from horizon to horizon.

The summer Milky Way spans the sky from horizon to horizon as seen from near Delta, Colorado. The galactic center is located just above the southern horizon (right).

I’m not here to give you a step-by-step guide to night sky photography, that’s been done before (try here, here, or here), but simply to encourage you to try it. All you really need to get started is a DSLR, a tripod, some patience, and somewhere dark. Like ACTUALLY dark. Sadly, light pollution has gotten so bad that most people reading this will have never seen a truly pristine night sky. Driving to the suburbs does not qualify as “dark”. Here in the Denver/Boulder/Fort Collins light pollution-opolis, even after driving two hours up to 12,000 feet in Rocky Mountain National Park, you’ll still only see roughly HALF as many stars as can be seen with the naked eye from a truly dark location. To see if there are any pristine night skies near you, check out this nifty site, which is basically Google Maps with an overlay of light pollution severity. You’re looking for areas with the darkest black color and as you’ll see, they are becoming few and far between.

What’s great is how many different ways there are to incorporate the night sky into your photos. With wide-field astrophotography, the entire night sky is the star of the show (pun intended). Accomplished by using fast, wide-angle lenses combined with relatively short exposures (30 seconds or less, unless you have a motorized mount), this method can reveal spectacular detail in the night sky unseen by the human eye, such as the spectacular interstellar dust lanes in the Milky Way. If you pair the Milky Way with a terrestrial landscape illuminated by moonlight, the possibilities for composing spectacular nightscapes become nearly infinite.

Milky Way center close-up

Close-up of the center of the Milky Way Galaxy. Dark arms of starlight-obscuring dust, star clusters, and emission nebulae (pink) are visible in this 1-minute exposure.

Longer exposures (or lots of short ones “stacked” together) document the motion of the stars across the night sky. I have a soft spot for star trails because they are a beautiful reminder that the world we live in is in constant motion; the dramatic and graceful arcs traced out by the stars are due to OUR rotation, not the stars.  Star trails centered around the North Star (Polaris) can be especially striking since the north star is almost exactly above the rotational axis of the Earth, and thus moves very little throughout the night.

Star Trails over Escalante Canyon, Colorado

Star trails (centered on Polaris) over Escalante Canyon, Colorado

Probably the most challenging type of astrophotography, and really the only one that requires specialized (often expensive) equipment, is telescopic imaging. My experience in this category is limited, given the aforementioned factors (donations always happily accepted!), but I’ve tried it on a handful of occasions by using friend’s equipment or telescopes at observatories I have worked at. Telescopic astrophotography allows detailed images of galaxies, star clusters, and nebulae, many of which are not even visible to the naked eye. While good images can be obtained by fitting a DSLR to a telescope (below, center and right), the best images are obtained using stand-alone CCD cameras optimized for astrophotography (below, left).

Deep-sky images taken with telescope

A variety of galaxies and nebulae imaged via telescope. 

Some objects, like the Moon, are big and bright enough that a telescope is not needed to get decent images. I got this photo of last month’s total lunar eclipse with a standard 55-200mm zoom lens, and even had enough light gathering ability to capture the planet Uranus less than a degree away from the Moon!

Total lunar eclipse October 2014

Total lunar eclipse on October 8 2014, as seen from Fort Collins, CO

Beyond the technical challenge, what ultimately thrills me most about astrophotography is being able to capture photons that have been en route towards us across the vast universe for dozens, hundreds, or even millions of years. After that long of a journey, it feels like our duty to ensure that at least some of those photons have the honor of being recorded in some state of permanence. Give it a try and it won’t be long before you find yourself in the middle of nowhere waiting for your camera to finish a 1-hour exposure. A perfect change to sit back and ponder the vastness of the universe looming over your head.

 


Capturing Cosmic Dust with a Camera: the Zodiacal Light

Cameras can be strange machines. We tend to think of cameras as devices that faithfully record the nature of the landscape around us, which they do…at least most of the time. When this paradigm does break down, it is usually because the camera has failed to record something important, something that made a moment or an experience worth remembering. Oftentimes when this happens, we become disappointed. How many times have you been scrolling through vacation photos and lamented at how poorly they turned out? Sometimes we even realize the limitations of the camera in the moment itself. Perhaps you’ve experienced something akin to standing on the rim of the Grand Canyon at sunset and becoming so resigned to the fact that no photograph will ever satisfactorily capture the grandeur in front of you that you begin to ponder the option of chucking your camera into the great chasm below.

On rare occasions though, the camera delights us by managing to capture even MORE than meets the eye. After returning from a recent camping trip to the San Juan Islands in northwest Washington, I was surprised to find an unexpected apparition in some of the long-exposure photographs I took from our campsite on the west coast of San Juan Island.

Getting to the San Juans is no easy task; it took me about 5 hours to get there, even though “there” is just 35 miles by air from my front doorstep. As a result, the islands can feel remote and isolated, but standing along the coast at night is a not so gentle reminder that you’re actually only about eight miles across the Haro Strait from Victoria, a metro area of more than 300,000 people. Taking advantage of a somewhat rare, perfectly clear Pacific Northwest evening, I took a series of 15 second exposures looking west across the strait which I composted into this 180 degree panorama:

SanJuanIsland_NightSky_Panorama

Click photo to embiggen!

The first thing you notice is the egregious light pollution from Victoria. Even the skyglow from Vancouver, five times further away but seven times more populous, is visible through the tress. Amongst all of the artificial light sources though, some natural ones still manage to shine through. The faint tendrils of the winter Milky Way just barely register on the camera’s sensor but the bright winter constellations of Orion, Canis Major, and Taurus forcefully punch their way through. If you look really closely, you’ll see a faint, slightly elongated, pale blue glow hiding in-between the lights of Victoria and Sidney. This is a phenomenon known as the zodiacal light, and it’s what took me by surprise when I started putting these images together. Here’s an annotated version to help you out:

SJI_Panorama_Annotated

See it? It’s a slightly different color than the light domes and isn’t as round and symmetrical as the light radiating from the cities, but rather looks squished and creeps upward into the sky at an angle. What really betrays the nature of this mysterious glow is its location: it coincides almost perfectly with the ecliptic, the plane of our solar system which is also the apparent path that the Sun, Moon, and planets follow as they move across the night sky.

What does this have to do with the zodiacal light? Well, it turns out that the plane of our solar system is home to lots and lots of dust. Not the dust made of dead skin cells and carpet fuzz you find around your house, but rather interplanetary dust particles made mostly of carbon, silicon, and oxygen. These dust particles are really small, on the order of 10 micrometers in diameter, about the size of a mold spore. The exact source of this dust is controversial; most of it is thought to be the result of collisions between comets and asteroids although some may be leftover from the formation of the solar system itself, tiny pieces of debris that never got incorporated into a planet. Regardless of where it cam from, the dust is really good at reflecting sunlight. Just after sunset (or just prior to sunrise), the angle between the Sun, dust, and Earth is such that the light reflected of the surfaces of the innumerable dust particles reaches our eyes (or cameras) here on Earth, giving rise to the zodiacal light.

When you consider how small the dust is (and that the dust particles are on average more than 2 miles apart from one another!), it’s not hard to understand why the zodiacal light is so faint and difficult to spot. Due to a quirk of celestial geometry, spring is a great time to observe it from the northern hemisphere, but even then spotting it with the naked eye requires extremely dark skies. The conditions in the San Juans, while darker than many spots in Western Washington, are far too light polluted. However, digital cameras are MUCH more sensitive to faint sources of light than the human eye. It’s actually rather common for a camera to detect things in the night sky that aren’t visible otherwise. On the night I saw the aurora borealis for the first time about a year and a half ago, its presence was first betrayed to me as a faint green glow hugging the horizon on my camera’s LCD screen, hours before it became bright enough to see with the naked eye. If not for my camera’s ability to detect it, I would have been fast asleep instead of standing in a marshy field near the Canadian border when the aurora dramatically brightened a few hours later and streamers began appearing all over the sky.

Have you ever captured anything on camera that you found surprising? Share your thoughts or stories in the comments below.


Airglow: Denizen of the Dark Sky

I’ve been an astronomy nut ever since my parents gave me a small reflecting telescope for my 10th birthday. I located Saturn, complete with its too-good-to-be-true rings, within 10 minutes of setting it up for the first time, although my parents refused to believe me until they had a look for themselves. I majored in astronomy, own a telescope that barely fits in my car, and come to think of it, every “real” job I’ve ever had has involved astronomy. NASA’s Astronomy Picture of the Day has been my homepage for longer than I can remember.

Given my disposition towards both astronomy and photography, it seems superfluous to say that I’ve always enjoyed astrophotography.  Taking photographs of celestial objects presents a set of challenges not encountered by photographers who go home after the sun dips below the horizon, the majority of which revolve around the fact that most astronomical objects are rather dim, requiring long exposure times and extra equipment to capture.

Quite frequently I’ll get asked if I’ve ever seen any UFOs while gazing up at the sky. My standard response is that, while I’ve certainly seen a lot of weird *#&@ in the sky, I’ve yet to see anything that didn’t ultimately have a logical explanation, even if it took a little head-scratching to figure it out (high altitude weather balloons are the worst!).

A prime example of this occurred this past summer during a nighttime observing and photography session. I was attempting to get a 180 degree panorama of our home galaxy, the Milky Way, stretching across the summer night sky. I had my camera mounted on a tripod head that compensates for the rotation of the Earth, allowing me to take exposures several minutes in length while avoiding star trails in my images. It was dark and clear enough that I was able to get some good shots of the summer Milky Way and its complex and sinuous inky-black interstellar dust lanes, as well as some decent shots of some galaxies and nebulae through a telescope:

MIlkyWayThe Milky Way in the constellations of Scorpius and Sagittarius. This portion of the Milky Way is home to the nucleus of our galaxy, making the Milky Way appear brighter here than anywhere else in the sky.

Lagoon_NebulaThe Lagoon Nebula, also known as M8, a vast cloud of hydrogen gas giving birth to new stars. A “stellar nursery” as astronomers like to say.

While my shots of the galactic center in the southern sky were turning out well, as I began to pan my camera around to the east and then finally north, I noticed that faint but noticeable bands of diffuse red and green light were creeping into my image.

DSC_2917

My immediate thought was sensor noise. The CCD chip on my old DSLR (a Nikon D70) had a habit of heating up during repeated long-exposures. This thermal radiation from the sensor manifested itself as a bright purple/pink haze occupying one corner of the photo, making any attempt at serious astrophotography futile. Perhaps something similar was happening here. I quickly ruled this out for a number of reasons. Most importantly, the apparition was showing itself only in photos taken towards the north, meaning that the source couldn’t be the camera, but rather something in the sky itself. The colors ruled out high clouds, and it wasn’t in the proper direction to be the result of artificial light pollution. The closest city of any significant size to the northeast was several hundred miles away.

Whatever it was, neither myself or any of my observing companions could see it with the naked eye.  A bit eerie perhaps, but not at all uncommon. Many astronomical phenomenon are too faint to see without long-exposure photographs. In fact, the first time I saw the aurora borealis, I captured it with my camera several hours before it became bright enough to see with the naked eye.

A auroral display was actually my second thought. What I was seeing in my photos definitely resembled one. Red and green are the colors produced by nitrogen and oxygen, the two primary components of our atmosphere, after being excited by collisions with magnetic particles brought to Earth by the solar wind. Most auroral displays consist of some combination of these two colors and what I was photographing appeared only in the northern sky which fit the theory to a tee.  Furthermore, the Sun had been especially active in the week or so prior. It was perfect except for one slight problem: I was in Colorado.

Auroras in Colorado are definitely not unheard of….but not exactly common either. One thing was certain: if an aurora HAD crept this far south, then the northern portions of the country would simultaneously be getting the show of a lifetime. A quick check of spaceweather.com, the one stop shop for up-to-the minute aurora information, showed this was not the case. Strike two.

I actually didn’t figure this one out until many days later, when I inadvertently ran across an article about some Pacific Northwest photographers who had captured something called “airglow” in some photos of the Milky Way taken at Mt. Rainier around the same time. A momentary glance at their photos and I knew I had my answer.

Milky_Way_Pano

Here’s the final panorama I produced. The airglow (red and green splotches at left) was changing rapidly enough that it caused major headaches trying to stitch the images together. Consequently I didn’t quite get my 180 degree panorama, there’s a bit missing on the northern end (lower left).

Airglow is exactly what it sounds like (a rare thing in science, I know…): glowing air. Incoming solar radiation and cosmic rays ionize oxygen and nitrogen atoms in our atmosphere during the day and then then these atoms regain their electrons at night, emitting light in the process. This is similar to what happens during an aurora, except that it’s happening ALL THE TIME. Airglow is always there, it’s just really, really faint; you need to be somewhere extremely dark to have a chance of seeing it, even with a camera. Even a miniscule amount of light pollution will render it invisible. It does tend to be brighter when solar activity is high, although it is not nearly as dependent on the solar cycle as its brighter cousin, the aurora.

So what began as an unidentified and undesirable annoyance in my photos (and when trying to stitch together my panorama, boy it sure was!) turned out to be a rarely captured celestial phenomenon I had never even heard of, much less one that I had intended on photographing that evening.  Next time someone asks me about UFOs, I’ll just refer them to this page.


The Sword of Orion

The Orion Nebula, composite of three 60″ monochromatic images taken in R, G, and B filters, SBIG 11000XM CCD Camera, Celestron C14, images processed using IRAF and stacked using Photoshop Elements. Taken from Whitman College Hall of Science.