How to See the Northern Lights from Jackson Hole, Wyoming

How to See the Northern Lights from Jackson Hole, Wyoming

The Myths

First let’s dispel some myths about the northern lights.

  • Northern lights can only be seen from Canada and Alaska (in North America).
    The northern lights (aka, aurora borealis) have been viewed as far south as Alabama and Arizona in recent years. In one of the strongest storms in recorded history, they were even seen in Hawaii. The strength of the northern lights (and thus how far south they’re visible) is dependent upon the strength of the impact of an incoming Coronal Mass Ejection. Put simply, the sun occasionally has reactions on its surface that send solar energy hurtling into space. If one of those outbursts happens to impact Earth, it causes a reaction in our magnetosphere. This reaction is the northern lights, and can appear colorful if strong enough (though cameras always pick up the color). So, the stronger the impact, the farther south the northern lights can be seen.

  • Northern lights are only visible in the winter.
    While the sun does have its own seasons, they have nothing to do with the seasons on Earth. Therefore, the previously mentioned eruptions are occurring throughout year. I personally have now seen the northern lights in every month here in Jackson Hole. In fact, both of these myths originated from essentially the same origin. Seeing the northern lights in northern Canada or Alaska is admittedly much easier. There are frequently much smaller reactions occurring in our magnetosphere that are much easier to see at those latitudes, and therefore much more reliable. The farther south you go from there, the harder the predictability. At the same time, since those areas also get 24 hours of daylight during the summer, you can’t see them at all in the summer, so you have to go in the winter since that’s the only time of year there’s enough darkness to see them. But where there’s night, there’s still a chance to see them.

How to Read the Northern Lights Forecast

On the right is a screenshot from a website that we frequently check, called SpaceWeatherLive. More specifically, it’s a screenshot from their Auroral Activity page. What this shows is six different readouts from NOAA about reactions that are occurring relating to the northern lights. (Note that this is only a screenshot and not live data.) While it can appear confusing and too much to understand at first, it’s actually really simple. For starters, I really only pay significant attention to two of the graphs.

The Kp-Index

Northern Lights Forecast

One of the most frequently checked graphs when looking for northern lights is the Kp-Index. In simple(r) terms, this measures the disruption of the horizontal distribution of the geomagnetic activity. It’s measured using an arbitrary scale from 0-9. A value of 0 means that even Fairbanks, Alaska would have difficulty in seeing the northern lights. 1-3 is most common, and that’s what is frequently seen in those northern latitudes of northern Canada and Alaska. A 4 would push them down into southern Canada, while a 5, in the right conditions, might just barely be visible on the northern horizon here in Jackson Hole. To see them well, we typically need at least a 6. If the Kp were to reach 7, it would be seen as far south as southern Utah and Colorado. The scale tops out at 9, and that’s when people in Mexico and Hawaii would be able to see them.
More information on the Kp-Index can be found here.

The Direction of the IMF (Bz)

While most people look at the Kp-Index to see a rough estimate of activity, it’s actually the direction of the interplanetary magnetic field (IMF) that has the biggest effect on auroras. If the IMF is trending southward, that will allow the coronal mass ejection to have a more significant reaction with our magnetosphere. This is typically northward facing, with the occasional dip southward. However, if it trends southward consistently and has a negative value of at least -5 (the lower the better), then things are looking good. Here in Jackson Hole, we’d want those values to push below -10 to be sure we’re getting a good show. During a really good reaction, it will be around -15 or so.
More information on the Direction of the IMF can be found here.

Finding the Best Location

In Jackson Hole, your best bet is to head out to the Antelope Flats area for the large wide open views away from light pollution. Unfortunately, there is currently too much light pollution in Jackson to be able to see them with the naked eye, and possibly even with a camera, so heading north up to the flats is the best location. Likewise, the backside of the National Elk Refuge might also make for good viewing. For those of you in Wilson and Teton Village, the Moose-Wilson Road just inside the south entrance of Teton Park is also an ideal location. There’s not quite as much light pollution produced by Teton Village as Jackson, and the large meadows before the road turns to dirt is a large enough area to get a clear view to the north, with multiple pullouts in the area. Please respect private property and their driveways if you’re out there though.

Basic Camera Settings

If you’re interested in capturing the northern lights on your camera, you’ll absolutely need your camera on a tripod. Also, auto settings will not work. The settings you’ll want to aim for are as wide of an aperture as you can get (f/2.8 or lower, ideally). You’ll want your ISO somewhere around 3200 (depending on your camera’s capabilities). Your shutter speed will depend on the intensity of the auroras. If they’re very strong and clearly visible, you can set it to about six seconds or so. Anything more will blur the ribbons of the auroras. If they’re weaker and in the northern horizon, you’ll need a longer shutter speed to absorb the distant light, so 20 seconds would be good in that case. Last, make sure your lens is set to manual focus and set it for infinity (if possible). Otherwise, focus it on a point of light as far away as possible, then set it to manual focus so it doesn’t try to focus again.

Conclusion

You should now be all set to see and hopefully capture the northern lights! If you have any questions or comments, feel free to leave them in the comments below.

How to Find Comet C/2014 Q2 Lovejoy

If you’re looking for a New Year’s miracle in astronomy, Comet C/2014 Q2 (Lovejoy) is about the closest thing to it. Discovered back in August, the comet was never supposed to achieve naked-eye visibility, but it already has! It will continue to brighten when it’s expected to peak some time around January 7th where it will be near Rigel and the Orion constellation. As of this writing, it’s currently on its way out of Lepus and heading higher and higher into the night sky.

Sky And Telescope Lovejoy Map

Moonlight will distract from getting a perfectly clear viewing through early January as we reach a full moon on January 4th, but the moon will start setting later and later after that, making the second week in January ideal for watching the comet. Don’t get too discouraged now though! With a pair of binoculars aimed in the right direction, the comet can be easily found and viewed, and since it’s growing in brightness, it will get even easier to spot with the naked eye.

The comet was named after Terry Lovejoy from Australia who has found several comets in recent years. It was 4,000 dimmer than it is now when he first discovered it and its rotation around our sun takes roughly 11,500 years! Due to the planets’ effects on the comet, it’s expected to return in roughly 8,000 years.

Check out the great printable map from Sky & Telescope on the right to see exactly where to look. For more detail and information on the comet, you can also read their article on Comet Lovejoy.

Astrophotography on a Budget

Astrophotography can seem like a daunting hobby to jump into. Indeed, there are definitely learning curves to overcome, but if it’s something you’re interested in pursuing, our astronomers are always happy to help you along in your goal to capture some deep sky objects with your camera. To help you get started, I’ve written up a simple guide to help you get going!

The Camera (of course!)

Naturally, the first thing you’ll need is a camera to photograph the night sky with. Though many options exist, we’re going to stick to the more budget-minded route since that’s where most people will be coming from. The most accessible option would be to get a DSLR camera, such as a Canon Rebel. Under normal, daylight circumstances, both Canon and Nikon reign supreme in the field of photography. With deep space photography, however, Canon has embraced the market much more noticeably than their competitors. This is primarily because Canon sells a modified version of their 60D camera called the 60Da. What’s the difference? (Besides the ‘a’?) Every camera comes with a filter that covers the sensor that makes the sensor more sensitive to visible light. The 60Da comes with a modified filter that is able to "see" more light than the standard filter (or your eyes), specifically Hydrogen-alpha particles. Hydrogen-alpha particles are important to astrophotography because they make up a significant amount of matter in many deep space objects. If you already own a camera in the Canon line, you can have that custom modified to have that filter replace the standard filter since the process is relatively simple and routine (though very tedious). Keep in mind though that this will void any warranty on the camera.

For my own astrophotography, I bought a used Canon Rebel T4i and sent it off to Hap Griffin to have him do the modification. He’s done hundreds of modifications and only charges a small fee added onto the cost of the filter. Given what’s involved with the modification, I found it well worth the price.

Of course this could be enough to get you started with some wide shots of the Milky Way Galaxy, for example, but to really zoom in and get some deep space objects, you’ll need a way of moving your camera with the stars. You’ll discover soon enough that the stars move much quicker than you think, and getting a crisp shot zoomed in on an object simply won’t work with your camera fixed on a tripod.

To remedy this, three solutions are available to allow your camera to actually pan with the stars, giving you the opportunity to take as many shots as you need of any visible object in the night sky.

Vixen Polarie

Vixen Polarie

For those with a limited budget, the Vixen Polarie is a great option that will mount on top of a tripod. Your camera then attaches to the device which keeps it turning against Earth’s rotation so your camera stays fixed on the stars.

A couple of key specifications to keep in mind: it will only allow up to seven pounds of weight, so mounting heavier lenses probably won’t be a good idea for this particular unit. The Vixen Polarie will shine however, with lighter, prime lenses.

The battery life is also an important item to keep in mind. At near room temperature, the Vixen Polarie will last for roughly four hours on two AA batteries. On colder nights, that time will drop of course, not leaving you too much time to capture fainter objects.

For more information about the Vixen Polarie, visit their website here.

iOptron Skytracker

iOptron Skytracker

For those willing to spend just a bit more than the Vixen Polarie, the iOptron Skytracker is well worth the extra money. The setup and operation is roughly the same as the Polarie, mounting onto a tripod, but the iOptron Skytracker supports 7.7 pounds and will also last for 24 hours at near room temperature on four AA batteries. Again, that time will drop in colder weather, but in that category, the Skytracker beats the other two options listed here.

This is the unit that I use and have been very pleased with the overall functionality and usability of it.

For more information on the iOptron Skytracker, visit their website here.

AstroTrac

AstroTrac TT320X-AG

The AstroTrac retails for about twice the price of the other two options, but is solidly built, lightweight, and combined with the wedge (sold separately), can support the heaviest of lenses for reaching deeper into space, supporting up to a whopping 33 pounds. Its battery life on eight AA batteries is 10 hours, which isn’t too bad, but you’ll definitely want to look into rechargeable batteries for this device. For the price, its features and functionality are unrivaled. Polar alignment is also significantly easier than both the Polarie and Skytracker, something that can easily take a few nights to really understand.

For more information on the AstroTrac, visit their website here.

Polar Alignment

Each device will have to be polar aligned, that is, aligned with the north star, Polaris. This is to ensure accurate panning and rotating. This step can be a learning curve in itself, and each device handles it slightly differently. The AstroTrac handles the alignment the simplest and smoothest, while the Polarie and Skytracker are a bit more cumbersome, but can still get the job done well enough once the quirks of each system are learned (ie, tightening knobs causing the alignment to shift slightly). In order to successfully align each device, a polar scope or similar tool will be required to hook onto the unit, and each will have instructions on how to correctly align the unit.

Why Prime Lenses

Many people instinctively want to get their best telephoto lens and zoom all the way into an object. After hours and hours of exposures, what they’ll find is that there’s a slight inconsistency found throughout all their photos, ruining the entire night of work. The reason is that as the temperatures begin dropping over night, the temperature changes will cause the lens itself to "creep" slightly throughout the night, changing both the focus and zoom. To avoid this, most people recommend using a prime lens, meaning, the lens itself is only one fixed focal length. A few popular examples are 50mm, 105mm, and 400mm. One trick I’ve found to avoiding this is to also use Canon’s 100-400mm L lens, which is one of the few on the market that can be "locked" to a certain zoom anywhere in its range. This has so far proved to be an effective workaround to the "creeping" which affects other telephoto lenses.

Image Capture and Post-Processing

Deep Sky Stacker

To capture your image, you won’t be taking a single exposure. There would be too much noise to be cleaned up and if your polar alignment is only slightly off, you’ll see trails from all your objects. Instead, the system that works for most people is to take a series of individual shots and "stack" together in a program such as Deep Sky Stacker (discussed below). That way, if a jet or satellite happens to fly through your image, you haven’t lost hours of work.

I’ve often simply set my camera to 30 seconds, which is what most cameras will max out at before going to Bulb exposure where you can specify a longer length. How many exposures you capture is entirely up to you. You can get a nice image with 20 shots, for example, but the more you capture the more information can be brought out in the stacking process. Some people will even capture objects for multiple nights in a row throughout each night. This will give you the most detail and bring out the faintest objects.

Think you’re done once you’ve gotten a bunch of shots? Not quite. This is just one of many learning curves. To counter the noise that will built up in your stacked images, you’ll need a series of what are called Dark Frames. This can be 15 or so images with the camera settings set exactly as your other exposures, but with the lens cap on. In simple terms, this will simply let the post-processing software know what’s noise, and what’s supposed to be in the final image.

As mentioned, Deep Sky Stacker is the preferred image stacker for most amateur and even professional astronomers, and it’s free! There’s a vast amount of features and options, many of which you’ll never click on, but it’s best to give the Frequently Asked Questions a quick overview before jumping right in.

Conclusion

In astrophotography, the word, budget, can be a very relative term. All the gear and techniques listed here though, are the least expensive ways to get in on the fun. If you have any questions, feel free to leave some in the comments, or come out to a free stargazing event where we’ll be happy to answer a couple of questions. If you’d like a more personalized experience, we’re also available to do private astrophotography sessions with you as well.

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