auroras

A while back, when I was still getting settled into the world of digital SLR photography, I found mention in a forum at dpreview.com of a possible approaching aurora storm. For as long as I can remember I'd been intrigued by auroras, I think everyone must be. I had seen them on two occasions, but only slightly. On both occasions all I could see was an angry red glow on the Northern horizon. The reason is that I don't live far enough North to see most auroras, those two occasions had to be outstandingly powerful aurora displays for me to be able to see them at all. Especially for me to be able to see them through the light pollution around here.

The post on dpreview mentioned a web site that has info for monitoring "space weather", the goings on in the area of space just outside Earth's atmosphere, or in the extreme upper atmosphere. Although I never saw anything from the display that the poster had been writing about, I started keeping an eye on that web site. Basically I REALLY wanted to see an aurora, I mean the real deal, lights in sky. Not just a vague red glow that looks more or less like light pollution.

For months I kept an eye on that web site, in time finding a page that collected info from a bunch of sources. It just happens that that site is run by a local astronomy group that I joined once, but never really did anything with and left after a year. On a side note, I think I should try joining again. I have no telescope of my own, but they have TWO observatory mounted telescopes that I'll bet would be great to plug my camera into.
http://www.stargazing.net/naa/cool.htm
That's the site, if anyone wants to check it out. It's just a collection of imagery from other sources, most of which you can click on to get further info. I can attempt to explain what all that is, but for now just understand that the SOHO pictures are taken from a satellite planted firmly at the Lagrange point between the Earth and the Sun, it can watch the sun continuously, and the others are from ground based observatories.

When I started out I didn't know what most of it meant, but as I watched I learned what was normal behavior on the graph image (click on it to see the graphs in more detail). I didn't know what proton flux was, but I knew what the proton flux chart did when a coronal mass ejection, or CME (a cloud of plasma ejected from the sun by a solar flare) hit the the magnetic field of the Earth. Similarly I had learned to look for a BIG "thump" on the magnetometer graph, which normally shows a fairly smooth, regular sine wave pattern. The KP index seems to be a measure or prediction of overall auroral activity, the larger the values the bigger the display.

For months I watched it. Once or twice I waited eagerly as a big CME headed Earthwards, only to either be blocked from seeing anything at all from overcast skies or else it just didn't make a strong enough display for me to be able to see anything. It became a part of my daily routine. Check email, check the space weather. After a while I started checking it less often, I was thinking that I'd probably have to go to Alaska or Northern Canada to see anything. But then one night, November 8th, 2004, I idly brought up the site. If it had been a scene in a movie, the background music would have gone from slow and boring to fast paced in an instant. The tension would build as I brought up the page with a picture of a model of the North Polar Auroral Oval. What was typically a boring yellow was a massive, bright red disc. The image predicting the area that the display would be visible in, which normally barely touches Northern Canada, was a similar bright red and covered most of the continental United States. There was a massive jump on the magnetometer graph, showing a huge impact on the Earth's magnetic field. For a moment I only stared. It was big, if anything was going to be visible from Illinois, THAT was. According to the visibility map it would be visible from Northern Florida!

Then I ran upstairs and looked out the window. Many times in the past I'd done so, and strained to see the slightest of lights in the sky only to see nothing. But I saw them. There were lights moving all over the sky. I think I literally blinked my eyes in disbelief and then looked again, to see if they'd gone away. They were still there.

It was winter, and still cold outside, but I didn't stop to put on a jacket. I slipped my shoes on and ran outside. There they were, flashes of light moving over nearly half the night sky. I probably giggled, it was so much more than I thought I'd ever be able to see from Illinois.
I ran inside and grabbed the backpack I kept my camera in and my tripod (and a jacket this time) and headed back out and briskly walked to a nearby neighborhood park that had trees that would block the streetlights so I could get a better view without the glare, and also hopefully let my eyes acclimate to the dark a bit more. As I was setting up the tripod I was thinking that it would be just my luck that a police car would pull up and I'd get hassled, technically the park does close at dusk. But there was no way I was missing that.

I had no idea how to take pictures of auroras, so I pretty much did a little bit of everything. Short high ISO shots, long low ISO, wide, zoomed in, the works. And every instant that the camera was busy taking a picture my head was craned skyward, I wanted to see every moment of that amazing display.
I was still giddy. For the first time I finally understood what auroras looked like! The pictures had never fully made sense to me, I gathered that they didn't quite show what it really looked like. Pictures show curtains of multicolored light hanging in the sky. But what I saw was flashes of light, unpredictably appearing and disappearing. Often the light would streak across a portion of the sky. And on the Northern Horizon a solid curtain of light, slowly moving up, the closest thing to what I'd seen in the pictures.
The one other thing I made sure to grab was my mp3 player. While I watched the display of tremendous energy in the sky I listened to spacey electronic music, mostly Apollo 440 I think. I made sure to check if I could hear anything from the auroras first, I'd read that some people claimed to hear a sound from auroras but that no mechanical device had ever been able to record anything. I couldn't hear anything either, but Naperville isn't exactly silent even in the middle of the night.

After about 45 minutes of taking pictures and staring at the sky the display began to taper off. After milking the waning display for everything I could I finally packed up and headed back home.

Of course I was sad it was over, but I knew it couldn't last forever. What was important was that I'd caught it, I'd finally seen what I'd wanted to see for so long. In a way it was less significant because I hadn't had to go anywhere to see it, but at the same time it was all the more amazing. When I was back at my computer I checked a map that showed the location of reports of visible auroral activity. Most of the US was covered in dots. It reminded me of what a tremendous event I'd just witnessed. Just as the visibility map had predicted, people had been able to see a red glow on the horizon in Northern Florida. Texas too. You just don't see auroras in Texas, it's was incredible!

As you can probably tell, it made a big impression on me. In terms of Disney World, I will always remember lying in my hotel bed after a day at the parks, and thinking about Journey Into Imagination at Epcot. It was a magical moment. The auroras were in many ways more special, because it was a random act of nature that I had no control over. I wasn't even in the right place, it was just that it was the right time that made almost any place the right place.

I didn't want to go to sleep that night because I knew that it would feel less real when I woke up the next day. It did, it's the sort of thing where I start thinking that the memories seem too unreal. But this time, I HAVE PICTURES TO PROVE IT!

Here's the deal, they're not as beautiful as many aurora pictures I've seen. I can't escape the light pollution, the sky just isn't as pristine as it is in many aurora pictures. I couldn't avoid getting streetlights in many of the shots either, but in a way that makes them more dramatic because you can see just how bright the auroras were.
As to the color, I didn't see much color. It's the nature of the human eye. We have two kinds of light receiving cells in our eyes, rod and cone cells. Rod cells are the "high ISO" cells, they can see very low levels of light but respond slower to changes. So actually they're kind of high ISO and slow shutter speed. But they don't see color, all they see is light and dark. The same thing happens when using telescopes, if you're dark adapted and can see faint objects they appear colorless. So I have no idea what color the auroras really were. It's clear that my camera saw color, but in terms of white balance.. I have NO idea what to do. How the heck do you white balance emission light coming off of oxygen and nitrogen in the upper atmosphere? There is no white point. So all I did was adjust the colors to try to make them pleasing, and I exaggerated the saturation a bit for dramatic effect.

I think you'd still get better images if you were farther North, these can't compare to what I've seen taken from higher latitudes. But to understand what you see in these, I think that the light was being made by blobs of light sweeping up from the horizon. I didn't see a solid curtain of light there at all. The shots of the solid curtain on the Northern Horizon didn't seem to come out clearly, I can't find any pictures that show what I saw of that.

Anyway, I haven't seen any other displays since then, although it's possible that I missed an even bigger one in 2005 because of weather. Partially it's been because the solar activity has been declining towards solar minimum, the period of time where the sun has the least activity in terms of sunspots and solar flares. But we've FINALLY officially passed solar minimum and are heading back to solar max. The bad news is that it takes an average of 11 years for a complete cycle, so we've got half of that until we're back to maximum. It's not fixed, it can be shorter or longer, but that's the average. Some models are predicting a very energetic maximum though. It doesn't have to be max to get good displays either, the display I saw was when the sun was already well past max. But we've been in the doldrums lately, we've had very little activity at all. I can't believe how low the solar X-rays have been. A C class flare was on the weak side back around when the display I saw happened (not just for that night, but for those months in general) but lately a C flare is big, the x-ray graphs have been almost flat lines whereas usually they're a bit livelier. Usually the question is if a particular sunspot group is likely to erupt into a large enough solar flare. Now the question is "are there any sunspots AT ALL?".

I still check the space weather page out of habit, but the chances of anything big happening are EXTREMELY low. We still get auroras, but they're only visible to people further north, or at least people with less light pollution. In the mean time this site:
http://www.spaceweather.com/

keeps me updated on other happenings in the sky. Interesting atmospheric optics like sundogs, meteor showers, shuttle and space station overpasses, and other such things. Most of this stuff is within easy reach of pretty much any camera, the only requirement being a tripod for the night stuff.

I know this has been a huge post, normally I try to keep things down in size (not that you'd know from reading it, I don't do terse or concise), but there was no way I could post these pictures with a big story. It was too big an event. Plus.. I get to relive it when I tell other people about it. The pictures themselves aren't fantastic, you can find much better ones at the spaceweather site. What makes my shots special is that they were taken in a suburb of Chicago instead of a fjord in Norway or someplace in Alaska.

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Those are brilliant looking! Great job.

 

Nice work I would love to be able to shoot that some time. I live in Florida so probably not gonna happen any time ever.

 

Last year a good friend of mine called me excitedly about lights in the sky. I drove out to see and the aurora was in full bloom. Looking very much like your pictures. As you so apply put it, it is a big event which fades in your memory over time. Thank you for reminding me of that night.

May I ask, what lenses you used? I was not prepared and didn't want to miss it so I left my camera at home.

 

That was just the Canon "kit lens", 18-55mm. It's not a great lens, not a terrible one (although some people absolutely hate it). It was all I had at the time, although I still haven't acquired anything that can go that wide, so if I want 18mm I still have to use it. A wider aperture would probably be useful, I think the shorter exposure pictures are more useful, rather than seeing a big blur of light you get a better idea of what the individual flashes of light are like. Although from what I've seen from people in more Northern latitudes... I think there may still be other types of auroral behavior that I have't seen, some of those pictures sure look like immense curtains of lighting hanging in the sky.

If I'm still active on this forum when the next good batch of CMEs roll around (it could be a few years down the road) I'll be trying to post warnings giving estimates for time of impact. That was part of my reason doing this, just to mention that if I happen to make a post saying "OMG, we just a massive X class flare and it was positioned ideally, in a day or two we might be having a big CME impact, stand by for further details" you understand why I sound so insane. It'll be because I'm geeked that I might have a chance to see auroras again.

Plus a bit of my disaster fascination kicks in. CMEs CAN cause terrestrial effects.. they can damage satellites that we rely on, they can cause power outages (although it sounds like we've gotten a lot better at preventing that, those massive CMEs didn't seem to cause any power issues, at least that I'd heard of), but.. they fall a bit short of being a disaster. But I can't help but think about the massive cloud of plasma headed our way, and the sort of energy that it carries. Early on there's sometimes a burst of relativistic protons (really fast, really high energy particles) that can also damage satellites and which poses a potential health risk to astronauts, that stuff is dangerous because we hardly get any warning, they're going almost as fast as light (there is research under way to better predict them, I gather they're not fully understood now). I think the ISS and Space Shuttle are adequately shielded, but if it caught an astronaut out on a space walk I think it has the potential to sicken them to the point of requiring bone marrow tranfusions to survive. The satellite imagery on that page that I linked to will show the effects of a proton bombardment, the images get all speckled as the protons hit the CCD imagers.

I'm sure that NASA keeps a close watch on any sunspots that are likely to cause such an event and would cancel spacewalks if there was a risk of such a bombardment, but I can't help thinking about the sort of incredible energy being unleashed upon the planet. It really makes me appreciate our magnetic field and our atmosphere (the magnetic field keeps the CMEs away, and the atmosphere is what stops the protons).

At the moment though... not so much. The solar flare ratings go a-b-c-m-x, with x being the most intense. It's an exponential scale, instead of going 1-2-3 it goes 10 to the power of one, ten to the power of two.. well, it's to negative powers, but the point is it's not a linear scale. Every step up means the steps themselves are bigger. I'm trying to emphasize how much bigger X is than C. And C is the last "big" flare we had. I'm not sure, but I think one of the satellite detectors is to the point where it can't detect the average x-rays, they're too weak. Good times for satellite operators, boring times for me.