Aurora!

September 28, 2011 • 6:41 am

When I was younger, I made a bucket list of four things I wanted to see before I turned into worm food.  They were the Taj Mahal, Mount Everest, Machu Picchu, and the northern lights.  I’ve now seen the first three, but not yet the last.

But I can do it vicariously: from EarthObservatory comes this stunning photograph of the aurora australis, the southern lights, taken only a few days ago (Sept. 17) from the International Space Station. It was taken between Madagascar and northern Australia, and you can see the station’s solar panels.

Be sure to click to enlarge:

If you want even more of a stunner—a video of the lights moving and flickering—be sure to watch either the high-resolution movie or the low-resolution movie appearing on the site, which compresses 23 minutes of time-lapse photos into a 35-second movie.  At the end of the movie you can see a bunch of wildfires and human-set fires in Australia.

And here’s how auroras are produced (also from the site):

In this case, the space around Earth was stirred up by an explosion of hot, ionized gas from the Sun—a coronal mass ejection—that left the Sun on September 14, 2011.

The pressure and magnetic energy of the solar plasma stretches and twists the magnetic field of Earth like rubber bands, particularly in the tail on the night side. This energizes the particles trapped in our magnetic field; that energy is released suddenly as the field lines snap the particles down the field lines toward the north and south magnetic poles.

Fast-moving electrons collide with Earth’s upper atmosphere, transferring their energy to oxygen and nitrogen molecules and making them chemically “excited.” As the gases return to their normal state, they emit photons, small bursts of energy in the form of light. The color of light reflects the type of molecules releasing it; oxygen molecules and atoms tend to glow green, white or red, while nitrogen tends to be blue or purple. This ghostly light originates at altitudes of 100 to 400 kilometers (60 to 250 miles).

h/t: Diane G.

47 thoughts on “Aurora!

  1. Yes, it’s the one thing I want to see before I “pop my clogs”. I figured that Iceland may be the most congenial place from which to achieve my goal.

      1. You must have been eating at the wrong places. One of the best meals I ever had was on a day tour of the northwest fjords. The driver called ahead to report the size of our group, and when we arrived at this country inn outside of Borgarness for lunch, waiting for us was the best meal of freshly-caught salmon I have ever had. After the driver called, someone was sent out to catch the fish. Wow! Talk about fresh – our lunch was swimming in the morning, done by noon.

  2. I, too, have yet to see the aurora. I very much doubt I’ll ever see the Taj Mahal or Everest, and Machu Picchu is only theoretically a less remote possibility…but I hope to have the opportunity sometime in the next few years, during the current maximum, to make my way far enough north to be able to see them.

    I suppose it’s not entirely impossible that they’ll make it as far south as Arizona, but I ain’t holdin’ my breath, that’s for sure.

    Cheers,

    b&

  3. The explanation that Jerry included states it’s caused by high-speed electrons. I assume that the thickness of the hull and little windows of the ISS is thick enough to block beta rays, but what about brehmsstrahlung x-rays? I wouldn’t be too keen on sitting by the window above an active aurora.

  4. Grew up in Anchorage AK. Just get away from that nasty light-polluted city in the followinf years during the dead of winter (and in a clear spell), and you’ve got a good chance of seeing them.

    (esp as you’re closer to the magnetic north pole than if you were on the other side of the planet)

    We’ve seen them in Colorado Springs – after we figured out what they were. (we mistakenly thought they were the lights of Denver, until they started dancing around). They’ll be much more impressive in the Northeast, I’d think. Why not treat yourself to an exciting dead-of-winter vacation in lovely Nunavut?

      1. I would LOVE to visit Nunavut though I doubt I could afford it, or that my conscience would allow me the carbon expediture which woill ultimately, sadly, ruin it.

        1. I heard that when the Northwest Territories split, there was a poll on what name to give the part that wasn’t called Nunavut. The most popular name was “Bob”.

    1. Wow. I have to keep up. I didn’t know magnetic North is zipping towards Russia @ 65 km/yr. Now in Arctic ocean N of Canada, though latest estimate of where it is seems tough to come by.

    1. I saw them long ago when I spent a night on the dunes at Grand Marais. That is the most spectacular star field I can recall seeing, and the aurora was great.

      It was at least 35 years ago but I’ll bet it hasn’t changed that much around there.

  5. Back in 1978 or so, a very active aurora was visible in Milwaukee. I was with some friends and a few bottles of mead at the Lake Michigan beachfront, and there was this vast, blue and green curtain across the sky over the lake. Milwaukee is at about 43° North, so they get at least that far south. I don’t think I’ll ever get to those other three.

  6. In terms of ‘congenial’ places from which to see them, don’t forget Fairbanks, Alaska (or, more appropriately, outside the city away from the light pollution).

    1. Here’s a photo my bro took (no special equipment besides a snowmobile) outside Fairbanks, in Nov 2003.

      I wish I could preview. Hope this works.

      if not, here’s a direct link.

  7. If you have trouble viewing the video [e.g. QuickTime Player or alternative not installed] ~ it’s HERE on YouTube at various resolutions with music added. There’s a few YouTube uploads of it, but the above is the best one that I could find

  8. Jerry,

    It’s a great list – all four are on my own, and I’ve so far visited Everest and Machu Picchu. But if I were to cut my own list right down, I wouldn’t be able to leave off … Venice.

    I thought I’d seen so many photos I almost didn’t need to bother, but the first incomparable sight, as I floated down the Grand Canal on vaporetto #1 late one summer afternoon, brought a definite moistness to my eye.

    If you haven’t been there, you must add it. Please.

    1. Personally, I’m quite ambivalent about Venice, primarily because it seems to be a tourist destination and only a tourist destination. And I hear that the smell can be quite intolerable at times.

      Florence, now that’s different. Florence is number 1 on my “return to” list.

      Pisa, with its leaning tower…meh. Aside from the area where the cathedral and tower are located, it’s a big nothing. And the tower itself is — well — just evidence of bad engineering followed by an overcommitment to a failed plan.

  9. I’ve never seen an aurora but would really like to. Someone told me you can hear a humming or crackling sound coming from it. Is that true?

        1. Both times I have seen it, I heard a humming, crackling sound. I was away from city/traffic noise though.

          Also, both times I was stationed at Great Lakes Naval Training Center. So between Milwaukee and Chicago might be too far south for normal displays, but still possible.

    1. I definitely heard a faint sizzling in Anchorage. There were no above-ground electrical wires there. In addition to explanations in the articles Michael Fischer linked to, it could be that the needles on all the pine trees around me had something to do with it. (or perhaps the fur on my parka that surrounded my face) It sounded to me like a singing saw, except way up there at the upper threshold of human hearing.

  10. Go up to the arctic circle and see it. It’s magic! And while you are at it you can see arctic ice before it disappears.

    1. You can access an animation here showing ice shrinkage from this season:

      http://earthobservatory.nasa.gov/IOTD/view.php?id=52230&src=eoa-iotd

      In 2007—the last time sea ice reached similarly low levels—conditions were ideal for melt. Skies were clear, wind patterns thinned the ice, and warm air temperatures melted the ice. Weather patterns in 2011, by contrast, were typical. This means, NSIDC scientists say, that the ice was thin and spread out before the melting even started in the summer of 2011. It is a sign that Arctic sea ice is thinning. Indeed the last five years include the five lowest sea ice extents since records began in 1979, and much of that trend has been caused by global warming, says NASA Cryosphere Program manager Tom Wagner in his video interpretation of the 2011 sea ice record (43 MB MPEG-4).

      (hotlink at the site)

  11. I saw a spectacular show in the late 1970s in the north of Skye at just over 57N. The display filled half the sky at times and my wife and I both heard a distinct susurration that we first thought varied with the intensity of the display, but were not so sure after watching for an hour. I should say that the night was so quiet that we could easily hear our own pulses as ‘squeaks’ in our ears and we could see to walk by the auroral light. The temperature was about 3 degrees.
    My long – suffering and shivering wife finally persuaded me to return to a log fire and a glass of Talisker. Do see the aurora, but choose your company as carefully as I did, or do it alone.
    I’ve seen Everest from a plane window, and doubt that I shall see your other two.

  12. I’ve seen the Taj Mahal, but not the others. It sounds like those lights should have been visible across most of southern Australia but I didn’t hear anything about it.

  13. On the topic of Taj Mahal, here is a popular Urdu couplet (in translation) giving a different spin to the whole thing:

    “An emperor, by constructing the Taj Mahal,
    Has mocked at the love of the poor like us,
    My sweatheart, you should meet me somewhere else.”

  14. Sorry you weren’t around as far south as NYC during the Sun Spot eleven year cycle “maximum, maximum” in the winter of 1954-55. The aurora got so stirred up that mobile telephones (pre cellular)in NY were talking to those in Philadelpia. That service was in the 150 MHz band which nomally is “line of sight.” The sun spots stirred up a giant reflector at the pole and Hams had a field day but mobile phones were yelling at each other,”Get off my line!” They sould hve been yelling, ‘Get off my frequency!”

    1. Thanks, that explains something. I distinctly remember being awakened around 3am in Northern Virginia when I was around 6 (1956) to try to see the Aurora. I didn’t see anything, but apparently there was some reason to expect that we might have seen something. So then when in Stockholm in early ’80s I figured I might have a chance to see it/them. People hardly knew what I was asking about. And so have still never seen them. Sigh.

  15. We get them every few years in Ottawa (45degN), though of course they tend to be washed out a bit if you’re not well out of town. And no doubt not as spectacular as they are further north.

  16. Today’s (30 September) Astronomy Picture of the Day is an aurora photo. The Picture’s caption reads:

    “On September 26, a large solar coronal mass ejection smacked into planet Earth’s magnetosphere producing a severe geomagnetic storm and wide spread auroras. Captured here near local midnight from Kvaløya island outside Tromsø in northern Norway, the intense auroral glow was framed by parting rain clouds. Tinted orange, the clouds are also in silhouette as the tops of the colorful shimmering curtains of northern lights extend well over 100 kilometers above the ground. Though the auroral rays are parallel, perspective makes them appear to radiate from a vanishing point at the zenith. Near the bottom of the scene, an even more distant Pleiades star cluster and bright planet Jupiter shine on this cloudy northern night. “

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