I’m sure what I can say about this, except that it’s oddly engaging.
I’ve been to VLA*, many years ago to do a video for an educational activity, and I don’t recall seeing them behave quite this way. Maybe I should’ve waited until night time.
Tip o’ the side lobe to my pal and science nerd Jeri Ryan on Google+.
* Yes, I know the name was recently changed to the Karl G. Jansky Very Large Array, but I’ll be honest: I don’t like the new name. If they had just called it the Jansky Array that’d be fine. But if the old name was clunky, it had an easy acronym. Now the name is longer and the acronym harder! So to me, it’ll always be the VLA. And get off my lawn.
I was fooling around with helioviewer.org, watching the flare in different wavelengths of light detected by NASA’s Solar Dynamics observatory, when I switched to 17.1 nanometers — in the far ultraviolet. At that wavelength, the glowing plasma that flows along the Sun’s magnetic field lines is very bright. The images were so beautiful, so incredible, I made a video animation of them, covering the time range of January 26, 2012 at midnight to January 28 at noon (UTC), which includes the huge X2 solar flare that erupted on the 27th. The video shows huge loops of magnetism on the Sun’s surface, glowing plasma flowing along them… and then 48 seconds in the flare changes everything. Watch:
Holy wow! Isn’t that awesome? Make sure you watch in in HD, and make it full screen to get the whole effect.
What you’re seeing is Active Region 1402, a sunspot cluster. This is a tangled collection of magnetic field lines piercing the surface of the Sun. Like a bar magnet, there are two poles to each loop, a north and a south pole. The gas on the surface of the Sun is so hot it has electrons stripped off, so it’s strongly affected by the intense magnetic field, and flows along these towering loops, which can reach heights of 300,000 km (180,000 miles) in this region.
The loops are tied to the plasma, too, and this material is twisting and roiling as it rises and sinks. The lines get tangled, and like a short circuit they can snap and reconnect. When they do, they release vast amounts of energy as a solar flare. In the video you can see the messy, disorganized loops getting more and more tangled up. Then KABLAM! The flare itself is not visible because it happened too quickly to be seen on this timescale (see the video yesterday for that). But you can see the effect on the magnetic field loops! They suddenly become far more organized, tight, and calm.
The Sun is fiendishly complex, and astonishingly beautiful. Clearly, to our brains, these things are connected. Remember, too: this beauty, this magnificence, is brought to you by science. Without our curiosity and our need to understand the Universe better, you would never have been able to watch in awe as superheated plasma arcs dwarfing the Earth itself grew and collapsed on the surface of a star one hundred fifty million kilometers away.
Think of that the next time someone says science takes away the beauty and mystery of life.
Photographer Alistair Chapman traveled to Tromso, Norway — 300 km north of the Arctic Circle — to capture video of the aurorae from the recent spate of solar storms. What he caught on camera is remarkable: shimmering, waving, dancing lights moving in real time!
[Make sure you set it to 720p; Chapman says higher-def footage is coming soon.]
That’s amazing. Aurorae video is generally done with time lapse to show the movement, which is usually slow. I’ve often wondered just how fast the movement really is; I always figured fluctuations in the solar particle density, speed, and magnetic fields would produce real-time changes in the lights, but I’d never seen anything like this! After a search of YouTube I actually found several more.
I know some people will think this is fake, and I had my skeptic hat on while watching it. Note that in most time lapse you can see the stars move; in this they don’t, indicating (unless it’s a complete fake) short periods of time during the filming. Given that, plus the existence of other video like it, I’m thinking this is real.
Mind you, the movement you’re seeing isn’t a physical motion. It’s not like solid curtains of material are flapping. The lights are caused by atoms in the upper atmosphere getting hit by subatomic particles blasted out by the Sun, caught by our Earth’s magnetic field, and funneled down into our air. These particles dump energy into the atoms, moving the electrons up in energy (called excitation). The electrons then jump back down, emitting light in the process (de-excitation). As I said in an earlier post, it’s like needing energy to jump up stairs, but releasing it as you jump down.
Different atoms have different energy levels for the electrons — think of it as more or less spacing vertically between steps in a staircase — so the energy emitted is different, resulting in different colors emitted. That’s why we see green, red, purple… they come mostly from oxygen and nitrogen in the air. So as the magnetic field fluctuates, the particles are sent shooting down in different places, giving the appearance of motion while the atoms themselves don’t move.
The physics is complex and interesting, but the beauty of these lights is, to use another term, magical. Not in the fantasy sense, but in the sense of the emotional response we have to them. They are simply breathtaking in these videos, and are a wonderful by-product of our tempestuous Sun.
Active Region 1402, the same sunspot cluster that blew out a solar flare and caused all the ruckus last week, is still being feisty: just before rotating to the other side of the Sun, it erupted in an intense, pulsing solar flare that actually was much more powerful than the one that happened last Monday. This was an X2 class flare, making it more than twice as energetic as Monday’s.
Happily, the flares were on the edge of the Sun’s disk, so the bulk of the radiation was aimed away from the Earth, but it still makes for some pretty dramatic footage. Using helioviewer.org I created a video showing about 2.3 hours of the Sun as seen by NASA’s Solar Dynamics Observatory. It shows the Sun in the extreme ultraviolet (at a wavelength of 19.3 nanometers if you wanna get geeky), where magnetic activity is seen easily. Watch the upper right corner of our friendly star… and make sure you make it HD and full screen.
Isn’t that awesome? The flare got so bright the automatic software dimmed the rest of the Sun to compensate, giving you an idea of just how powerful these flares can be: at peak, they can give off several percent of the entire Sun’s brightness in one small spot! I love how you can see it pulsing over the course of several minutes; I counted 10 separate flaring events. Each pulse was from a snapping of the Sun’s magnetic field lines, a cascading series created when the first one went off and triggered the rest. And each released mind-numbing amounts of energy — tens of thousands of times our entire planet’s nuclear arsenal combined. Also, you can see the arcing loop around the flare site; that’s plasma trapped in a field line. It erupts outward, but bear in mind the scale: it’s several hundred thousand kilometers across, roughly the distance from the Earth to the Moon, and it blasts away from the Sun like the devil himself is after it.
Like I said: awesome.
You might have noticed the flare looked like an elongated diamond. That’s not real! It’s a digital artifact; what’s happening is the flare got so bright it overwhelmed the pixels in the SDO detector. These collect light like a bucket collects rain. If too much light hits them, they overflow into the neighboring pixel. This flare was so bright it flooded the detector, and created that effect — technically called blooming.
We haven’t seen much of an effect from this flare — just a minor radiation storm that’s at the lowest end of the scale, nothing to worry about — since it wasn’t pointed at us. Had this been in the center of the Sun’s disk, well. That might’ve given me my chance to finally see some aurorae from Colorado. Not this time, though, and sunspots generally don’t last long enough to make it all the way around the Sun again (which takes about 30 days to spin once). But the Sun has a lot of magnetic energy still up its sleeve, and we’ll be seeing more flares like this as we approach the peak of the cycle in 2013 and 2014.
The solar storm that erupted from the Sun yesterday reached the Earth today at about 15:00 UTC (10:00 a.m. Eastern US time). The wave of subatomic particles has been impacting the Earth’s magnetic field, and we’re starting to see some auroral activity:
Isn’t that lovely? That was taken at 18:00 UTC today from a webcam in Abisko, Sweden. Can you see the handle of the Big Dipper right below the green curtain? [More aurora webcam sites are listed below.]
The two biggest questions I’m getting on Twitter and Google+ are 1) is there any danger to this storm, and b) can I see the aurora from [my location]?
First, no, we’re not in any danger from this event. Even though it sounds terrifying — an explosion the equivalent of billions of nuclear weapons launching hundreds of millions of tons of subatomic particles Earthward at speeds of million of kilometers per hour! — we’re pretty well protected down here on the surface. The Earth’s magnetic field catches the particles, and most of those get dumped harmlessly in our upper atmosphere. That can create the aurora displays, but won’t dose everyone with radiation and give them superpowers.
Sorry. [UPDATE (19:00 UTC): a ground current surge was reported in Sweden, but so far that's the only physical impact I've heard of.]
But the aurorae are pretty cool, and that brings us to the second question. The answer depends on where you are, and when it’s dark out. As I write this, activity is on the rise. Here are some live webcams for aurorae, some of which are showing spectacular activity! Note they only show views when it’s nighttime locally:
I’m getting conflicting info on potential aurorae tonight; the webcams in Scandinavia listed above are showing strong (and gorgeous) activity, but the prediction for Canada and the US appear moderate at best. But don’t let that discourage you! If you have clear skies, go outside once it’s good and dark and take a look. Even if there’s no aurora, you can see Venus and the thin crescent Moon to the west right after sunset, and that’s always a plus. And if things perk up, you might get a nice light show to the north, too!
Around 04:00 UTC on Monday morning, January 23, 2012, the Sun let loose a pretty big flare and coronal mass ejection. Although there have been bigger events in recent months, this one happened to line up in such a way that the blast of subatomic particles unleashed headed straight for Earth. It’s causing what may be the biggest space weather event in the past several years for Earth: people at high latitudes can expect lots of bright and beautiful aurorae.
I’ll explain what all that is in a second, but first here’s a video of what this looked like from NASA’s SOHO satellite.
Wow! Make sure you set it to high def.
So what happened here? The sunspot cluster called Active Region 11402 happened.
Sunspots are regions where the magnetic field lines of the Sun get tangled up. A vast amount of energy is stored in these lines, and if they get squeezed too much, they can release that energy all at once. When this happens, we call it a solar flare, and it can be mind-numbing: yesterday’s flare exploded with the energy of hundreds of millions of nuclear bombs!
In the image above, the sunspots are caught in mid-flare, seen in the far ultraviolet by NASA’s Solar Dynamics Observatory (it’s colored green to make it easier to see what’s what). We think of sunspots as being dark (see the image of AR 11402 below), but that’s only in visible light, the kind we see. In more energetic ultraviolet light, they are brilliant bright due to their magnetic activity.
A huge blast of subatomic particles was accelerated by the explosion. The first wave arrived within a few of hours of the light itself… meaning they were traveling at a significant fraction of the speed of light!
But shortly after the flare there was a coronal mass ejection: a larger scale but somewhat less intense event. This also launches particles into space, and these are aimed right at us. The bulk of the particles are traveling at slower speeds — a mere 2200 km/sec, or 5 million miles per hour — and is expected to hit us at 14:00 UTC Tuesday morning or so. That’s basically now as I write this! Those particles interact with Earth’s magnetic field in a complicated process that sends them sleeting down into our atmosphere. We’re in no real danger from this, but the particles can strip the electrons off of atoms high in the air, and when the electrons recombine the atoms glow excite the electrons in atoms high in the air, and when the electrons give up that energy the atoms glow. That’s what causes the aurorae — the northern and southern lights.
If you live in high latitudes you might be able to see quite the display when it’s dark — people in eastern Europe and Asia are favored for this, since this happens after sunset there. But the storm is big enough and will probably last long enough that everyone should check after dark: look north if you live in the northern hemisphere and south if you’re south of the Equator. There’s no way in advance to know just how big this will be; it might fizzle, or it might be possible to see it farther away from the poles than usual. Can’t hurt to look! Also, Universe Today has been collecting pictures of aurorae from the solar blast earlier this week. No doubt they’ll have more from this one as well.
As I said, we’re in no real danger here on Earth, and Universe Today has a good article describing why the astronauts are probably not in danger on the space station, either. Even if this were larger storm, the astronauts can take shelter in more well-protected parts of the station, too. Bigger storms can hurt us even on Earth by inducing huge currents in power lines which can overload the grid. That does happen — it happened in Quebec in March of 1989 — and it may very well happen again as the Sun gets more active over the next few years. [UPDATE: a ground current surge from today's event was reported in Norway.]
But we should be OK from this one. If you can, get outside and look for the aurorae! I’ve never seen a good one, and I’m still hoping this solar cycle will let me see my first.
On Sunday, I did a live video chat on Google+ where I took astronomy and space questions from folks and answered them as best I could. It was a lot of fun, with several hundred people showing up! I did some minimal editing of the session and put it on YouTube for your enjoyment:
The video resolution is not that great, I know, and I’m working on solutions for that. I’m looking into recording the feed locally on my PC so that I can upload a better version. If you have suggestions, I’m listening (but anyone starting a PC vs Apple war will be eviscerated; be ye fairly warned, says I).
I’m also always happy to get suggestions from people too. I have plans to do this on a weekly basis, and would love to improve it. Whaddaya got?
[P.S. In the "Related posts" below I have some links to the old Q&BA v.1.0 videos. Those got to be so time-consuming I had to stop doing them, but things have gotten much better since then! I'm looking forward to doing this more often now.]
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
"If things worked the way I wanted them to, any reporter about to do another 'sensational' story on deadly meteors would consult this volume, and bang! common sense would find its way into the news. How strange would that world be?" -- Adam Savage, Mythbusters
"Reading this book is like getting punched in the face by Carl Sagan. Frightening, but oddly exhilarating." -- Daniel H. Wilson, author of How to Survive a Robot Uprising
But shortly after the flare there was a 
