Exploring the Earth and Sky of the West

Posts tagged “night sky

From Washington to Zion

Cliffs of white and tan rock are streaked by dark red coloring, and dusted by a light layer of white snow.

Between work, weather, and the ongoing pandemic, my camera has seen relatively little use the last few months. Here in central Washington, it is inversion season. Atmospheric inversions occur when relatively warm air passing over the Cascade Range traps colder air below in the valleys of the Columbia River Basin. These pools of cold air can persist for weeks, bringing cold temperatures, freezing fog, and poor air quality. Fun, fun, fun! Here’s what things have looked like in recent days:

A thin layer of fog and pollution sits in broad valley.
On many days, getting above the inversion and into the sunshine requires only a short drive or hike to the crest of one of the many low basalt ridges that crawl across central Washington. Here, some pollution and fog lingers in the Upper Yakima Valley below.
Other days, even a 1500 foot climb doesn’t get one above the fog. Here, rime ice coats the sagebrush on Rattlesnake Dance Ridge, Yakima River Canyon, Washington.

Stuck inside, I’ve been working on a project to organize and categorize over a decade’s worth of photos. It’s been fun to come across long forgotten gems and months and months of photos that I never even got around to editing in the first place. I plan to post some of the highlights as I come across them.

While I post only a tiny fraction of the photos that I take here, looking back through the archives, I’ve noticed one especially glaring omission over the past few years: Zion National Park. Zion is one of my favorite landscapes on Earth, and for a little over three years we lived just 20 minutes from the north end of the park. I was surprised to discover that I haven’t shared any images from Zion since I started this website and blog almost a decade ago. In order to rectify that, here’s a look back at some of my favorite photos from Zion National Park:

Cliffs of white and tan rock are streaked by dark red coloring, and dusted by a light layer of white snow.
The Altar of Sacrifice after a February storm, Zion National Park, Utah
An isolated mesa dotted with trees is perched above cliffs of white sandstone
An isolated mesa, Zion National Park, Utah
An ornate brown, white, and orange butterfly perched on a leaf
California Sister (Adelpha californica), Zion National Park, Utah
A small creek flows through a canopy of green cottonwood trees with cliffs of red rock in the background
La Verkin Creek, Zion National Park
Stars and planets dot the sky over cliffs and canyons of red rock
The night sky from the Kolob Canyon area of Zion National Park, Utah. Light pollution from Cedar City, UT is visible on the horizon at left.
A tan lizard with brown and yellow spots and a thick black neck stripe rests on some rocks
Great Basin Collared Lizard (Crotaphytus bicinctores), Zion National Park, Utah
A lizard sits on a ledge of orange sandstone with a small arch in the background
An unidentified lizard hangs out next to a small sandstone arch, Zion National Park, Utah
Vast expanses of white and tan rock dotted with small trees and shrubs
Vast expanses of sandstone slickrock in Zion National Park, Utah
A river winds through the bottom of a deep canyon with sheer rock walls
Zion Canyon from Observation Point
A bighorn sheep with short horns peer down from a ledge of rock
A desert bighorn sheep (Ovis canadensis nelsoni) in Zion National Park, Utah
A trail winds through pine trees and vast expanses of white sandstone
Clouds build over the White Rim Trail, Zion National Park, Utah
stars streak across a purple sky, with cliffs of red rock and lots of trees in a canyon below
Star trails over the La Verkin Creek drainage, Zion National Park, Utah
White and red boulders sit in a dry wash with towering orange cliffs above
A dry wash in the Kolob Canyon section of Zion National Park, Utah

Does the Milky Way Really Look Like That?

The Milky Way is visible in the night sky over a smoke filled lake.

The Milky Way stretches from horizon to horizon with some clouds hovering near the horizon.

The summer Milky Way from Cedar Breaks National Monument in southern Utah.

Capturing stunning images of the night sky has become much easier in recent years. The low-light performance of modern cameras (and even my six-year old Nikon D750) far outpaces the capabilities of cameras made even a decade ago. Recently, I was flipping through some old astronomy magazines from the early 2000s and was shocked not only by the (low) quality of the wide-field astrophotography of the day, but also by the incredibly expensive gear used to produce those images at the time. 20 years ago, it was extremely difficult to capture a detailed image of the Milky Way without a high-end camera and an expensive tracking mount.

Today, even some phone cameras can capture passable images of the Milky Way. Stunning panoramas of our galaxy stretching from horizon to horizon are now a dime a dozen on social media. Given the advanced abilities of today’s cameras, it is natural to wonder: “Does the Milky Way really look like that?” Do the spectacular Milky Way images we see plastered across the internet accurately represent what the human eye can see? Or is this incredibly rich detail only visible to a high-tech camera sensor? Or, more nefariously, could these images simply be the result of some Photoshop trickery? The answer, perhaps not surprisingly, is a combination of all three!

Let’s begin by discussing one way in which most Milky Way images are not representative of what the human eye would see: color. The Milky Way will always look monochromatic to the naked eye. However, the reason why has to do more with the physiology of the human eye than any deception on the part of the photographer. Let me explain.

Some photographers do like to crank up the saturation of their Milky Way images beyond belief. Night sky photos with vibrant blues, purples, oranges, and pinks are the tell tale signs of digital embellishment. Rather than point fingers, I’ve created my own version below to illustrate:

A photograph of the Milky Way with extremely vibrant colors

An image of the Milky Way (and a meteor) over Mt. Adams in Washington state…with the saturation slider cranked up to 100 in Adobe Lightroom.

To be clear, these colors aren’t real. This is Photoshop trickery, pure and simple. Here’s what the same image looks like without the saturation increase:

A photograph of the Milky Way galaxy hovering over a tall volcanic peak.

The same image, with natural color.

Much more subdued, certainly, but look closely and you’ll see that there is still some color there! Here’s the good news: those colors ARE real! Notice the pale green sky behind Mt. Adams. That’s airglow, a phenomenon caused by gas molecules in our atmosphere re-emitting energy they absorbed during the day in the form of ultraviolet radiation from the Sun. If you open the photo full screen and look really closely, you can also see some small pink-ish blotches along the plane of the Milky Way. These are hydrogen gas clouds—stellar nurseries if you will—glowing with the characteristic ruddy hue of ionized hydrogen.

Now for the bad news: while these subtle colors are “real”, you’ll never actually see them with the naked eye. Why not? To sum it up, our eyes suck at seeing colors at night. We see using two different sets of cells in our retinas: rods and cones. The cones are what allow us to see color. Unfortunately, the cones only work when there is lots of light entering our eyes, like during the day. Our rods are mostly responsible for our night vision and they are, sadly, colorblind. This is why the night sky (and low light scenes in general), always appear in shades of gray. Only a few of the brightest stars and planets emit enough light to trigger our color-seeing cones. The diffuse glow of the Milky Way does not.

Cameras on the other hand don’t have rods and cones. They are much better at picking up color in low light, so they naturally produce images that are more vibrant than what we actually experience…no editing necessary!

With this in mind, let’s remove the color entirely from our Milky Way image:

A photograph of the Milky Way galaxy with all color removed

Our Milky Way image converted to black and white, a more accurate approximation of what the human eye sees at night.

With the color out of the picture, is this now what the Milky Way actually looks like to the naked eye? Yes…under certain circumstances.

Look closely at the Milky Way in the image above. Notice the detail. It’s complex. It’s interesting. Some parts are brighter, others fuzzier, with dark blotches and voids winding sinuously from upper left to lower right. The Milky Way is a complex place, and this manifests itself in our view of it from Earth. In this regard, this photo actually does a pretty good job of depicting what the Milky Way actually looks like. You CAN see this detail and complexity with your own eyes…provided that a few things are true:

#1: You have a dark sky. For most people, light pollution prevents the Milky Way from being seen in its full glory. If you want to see the kind of detail shown in a photo like this one, you need to be somewhere dark. Not “turn off the porch light” dark. Not “drive out to the edge of town” dark. Not even “drive an hour up into the mountains” dark. Light pollution is incredibly pervasive and the view of the Milky Way can be degraded for literally hundreds of miles from a major city. Even some of the most remote wilderness areas in the United States are still awash in the glow of artificial light. Places like eastern Oregon, central Idaho, northern Nevada, and southern Utah are among the few locales where you can still experience a pristine night sky. A view of the Milky Way from anywhere else simply doesn’t compare.

#2: Your eyes are dark adapted. Remember the rods from earlier? While our rods allow us to see fairly well in low light, they need at least 20-30 minutes of darkness in order to reach peak sensitivity. This period is known as “dark adaptation” and it is a key ingredient of a successful stargazing session. Gazing at the Milky Way before your rods have had time to fully dark adapt is like looking at a Van Gogh or Monet with dark sunglasses on; you miss many of the finest details. If you walk out of a brightly lit RV or tent and look skyward expecting to see the Milky Way like it appears in a photo, you’ll be quite disappointed. Even using a headlamp or checking the time on your phone while waiting for your eyes to dark adapt can inhibit the process. For this reason, astronomers typically use red lights at night because our rods are less sensitive to that color, making it easier to preserve night vision.

#3: You are in the right place at the right time. We live in the suburbs of the Milky Way galaxy. When we look toward the center of the Milky Way (downtown), it looks brighter, because we are looking at a greater concentration of stars, gas, and dust. When we look away from the center, it looks dimmer. Images like the one I’ve been using in this post are taken looking downtown…toward the galactic center. This portion of the Milky Way is only visible during certain times of year. In late fall, it’s behind the Sun, making it rather difficult to photograph or see. Late evening in the summer and early fall, or early morning in the Spring is the ideal time to catch it. At other times of year, when the galactic outskirts grace our sky, the Milky Way is much more ho-hum. You’ll also want to avoid the Moon, whose glow will mostly overwhelm the diffuse and relatively faint Milky Way.

If all three of these things are true, then yes, the black and white image above is a good representation of what the Milky Way looks like to the naked eye. Sadly, only about 20% of North Americans can even see the Milky Way from their homes, much less see it under ideal circumstances. Light pollution has masked the view of our home galaxy to the point that most of us no longer know what it should look like. Ecologists call this “shifting baseline syndrome”, a phenomenon in which each successive generation comes to regard the state of the environment around them as “normal”. In other words, as we degrade our environment, we gradually forget what things used to be like, or, in this case, look like.

While increasingly rare, such a view of the Milky Way is one of the most spectacular sights in the natural world. I vividly remember a backpacking trip I took over a decade in Aoraki/Mt. Cook National Park in New Zealand. The Milky Way appeared so bright that it cast shadows on the ground, and I was able to read a book (albeit barely…) by its light. Oddly enough, sometimes the “darkest” skies are actually the brightest because so many stars are visible.

Fortunately, light pollution is an easy problem to fix. Many outdoor light fixtures are poorly designed and allow light to escape upward into the night sky. While our modern lives certainly require light at night, that light is almost always needed on the ground, not up in the sky. Illuminating the sky or the crown of a tree makes no one safer or more secure from hazards real or imagined. Light fixtures that direct light downwards (known as “fully shielded” fixtures) eliminate much of the problem. Cities that use such lights, like Flagstaff, Arizona (where I grew up), produce substantially less light pollution than other cities of comparable population. You can see the summer Milky Way from downtown Flagstaff…a city of nearly 100,000 people. Simple actions can go a long ways toward preserving the view of the Milky Way for future generations. (For more on what you can do to combat light pollution, check out the great work being done by the fine folks over at the International Dark Sky Association.)

The Milky Way is visible in the night sky over a smoke filled lake.

A view of the Milky Way over Crater Lake in southern Oregon. A layer of smoke from the 2020 Oregon & California wildfires is seen near the horizon.


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!