Yesterday, an active region on the sun – basically, a collection of magnetically active sunspots – popped off a series of flares that were actually fairly energetic. NASA’s Solar Dynamics Observatory caught the action in this video:
Neat! These shots were in the ultraviolet, where flares are easier to spot.
Sunspots are where the Sun’s complex magnetic field pokes through the surface. The field lines store ridiculous amounts of energy (did you see my BAFact for today?), and allow plasma – superheated, ionized gas – to flow along them. Think of these field lines like a pillowcase full of tightly wound springs. If one of them snaps – which can happen if they get too close to each other, for example, or when the churning surface of the Sun ratchets up the tension in the field lines beyond their capacity to restrain themselves – it blasts out its energy, which then snaps other lines, which release their energy, and so on. You get a cascade of explosions, resulting in a solar flare.
Flares can be pretty small, or hugely huge. Scientists categorize them by the amount of X-ray energy released, so we have low-energy C class, medium M class, and yikesingly X class. This flare from yesterday just edged into X class territory, so it was decent, but not too bad. Happily it was on the edge of the Sun, and the blast was directed away from Earth, so it’s not expected to affect us. For further reassurance, there have been 14 previous flares since this new sunspot cycle began a couple of years ago, and we’re still here.
However, as the Sun spins, this active region is rotating toward us. If it stays active, we could see some interesting events from it that can cause aurorae on Earth. The odds of anything bad happening – power outages, or loss of satellites, for example – are low, but not entirely zero. I personally am not too worried about it, but it’s always good to keep our eyes on our nearest star. It can pack quite a punch, and we’re still a year or so away from the peak of the current sunspot cycle.
Image credit: NASA/SDO
Early this morning, while you were sleeping, or working, or reading Twitter, the Sun had different plans: it erupted, blasting an immense tower of plasma upward off its surface:
[Click to enheliosenate.]
This image was taken by NASA’s Solar Dynamic Observatory at 08:15 UTC this morning. The scale of it is staggering. The Sun is 1.4 million kilometers across – 860,000 miles – so this plume was at least 400,000 km long. Going back through the images, it had been brewing for hours, but really got its start around 05:00, meaning it erupted upwards at well over 100,000 km per hour. That’s fast enough to cross the face of our planet in less than 8 minutes.
By the way, did I mention the total mass of such a prominence is billions of tons? And the Sun does this kind of thing all the time.
We’re in no real danger from an eruption like this, especially this one: it’s on the Sun’s limb, so it was heading away from us. But these events can trigger storms like coronal mass ejections, where billions of tons of material is sent hurtling across the solar system at mind-crushing speeds. Those can interact with our magnetic field, creating havoc with our satellites and causing power outages.
But that’s why we keep an eye – many eyes, in fact – on our Sun. Never forget: our Sun is a star, with all the power and fury that implies. The better we understand it, the better we can protect ourselves from it when it gets angry.
Image credit: NASA/SDO. Tip o’ the welder’s glasses to Camilla SDO.
In August, the Sun erupted in an epic explosion: a towering arc of material blasted off the surface and into space. The images of it were incredible enough, but the folks at NASA/Goddard Space Flight Center put together an astonishing high-def video of the eruption as seen by the Solar Dynamics Observatory, the Solar Terrestrial Relations Observatory (or STEREO), and the Solar Heliospheric Observatory (SOHO):
Yowza. Set it to hi-res and make it full screen. Try not to drool.
They have more images, videos, and higher-resolution stuff on the GSFC Multimedia site. You really want to go there and take a look.
Our Sun is gorgeous, and dangerous, and amazing. These pictures and videos are more than just beautiful; they are telling us about the mechanisms and processes occurring both on the surface and inside our nearest star. Given the impact this can have on Earth, the more we know, the better.
On August 31, the Sun threw a major tantrum. It started with a vast arc of material towering over its surface, a stream of plasma flowing between two sunspots. Sometimes these collapse back down to the Sun’s surface, but this one exploded, blasting hundreds of millions of tons of material out into space.
SDO captured this ridiculously awesome picture of the arc just before it erupted:
Holy solar hissy fit! [Click to enfilamentenate.]
This picture is a combination of two images, both in the extreme ultraviolet part of the spectrum (30.4 and 17.1 nanometers, to be specific), where magnetic activity is easy to spot. The bright spot to the upper left is a sunspot, which are normally dark in optical light, but shine brightly in the UV. The filament, as the arch is called, is so big it’s hard to comprehend: it was something like 300,000 kilometers (nearly 200,000 miles) across! That’s nearly enough to extend from the Earth to the Moon.
Having a hard time picturing that? Yeah, me too. Happily, NASA provided an image with the Earth for comparison. Yegads. And there are more images of the event on the NASA/Goddard Flickr page.
Stephen Ramsden is an astronomer who runs the Charlie Bates Solar Astronomy Project, and he saw it while at Dragon*Con! I was at D*C but totally missed this, but he got a very cool picture too. As you can see in this picture, it was erupting when he caught it. I’m kicking myself to have missed the solar observing at the con, and next year I’ll be sure to take a look. I’d hate to miss something like this again!
For his non-profit Charlie Bates Solar Astronomy Project, Stephen takes solar telescopes across his region and uses them to teach people (including kids!) about the Sun and its effect on us. I’ll note he accepts donations to help him do this. Hint hint.
Finally, I’ll add that this amazing solar eruption traveled outward at about 1500 kilometers per second (900 miles/second) and nicked the Earth’s magnetic field on September 3, sparking aurorae in extreme latitudes. This had little real impact on us, but I gently remind you the Sun is still not at its peak. It’ll reach the max of its cycle next year sometime, and the biggest flares and other storms tend to happen a few months after the peak. It’s hard to say if this will do any damage – loss of satellites and power blackouts are possible, though no direct harm to humans on Earth can happen – but we’ll see. The most likely outcome is aurorae, so keep your browser tuned to the NOAA Space Weather Prediction Center and SpaceWeather. If we do get aurorae, those are great places to let you know.
Images credit: NASA/GSFC/SDO; Stephen Ramsden
’tis the season for solar storms, and I’m hearing reports that Active Region 1504 (the same sunspot featured in a dramatic video I posted recently) has been getting feisty, blowing out some flares and causing auroral activity here on Earth.
Photographer Brad Goldpaint was in the right place at the right time Saturday night to see some of this: he went to Crater Lake, Oregon, and at 3:30 a.m. local time on June 17th he took this surpassingly beautiful picture of a somewhat rare event: pink aurorae!
[Click to recombinate.]
Gorgeous! And weird. The colors you see in aurorae depend mostly on what’s in the air. Literally! A solar storm is an eruption of subatomic particles launched from the Sun at high speed. These interact with the Earth’s magnetic field, which, through a complicated process, sends those little beasties down into our air. They slam into the molecules and atoms in the upper atmosphere, blasting off electrons like bullets hitting concrete and sending out shrapnel.
When electrons recombine with the atoms and molecules, a little bit of energy is released in the form of light, and the color of that light depends on what’s doing the emitting. Oxygen atoms, for example, tend to glow green and/or red. Oxygen molecules (two atoms combined, like the kind we breathe) glow blue. Nitrogen molecules can glow either red or blue. Here’s a diagram from the excellent Atmospheric Optics website:
I love it when people take electromagnetic phenomena (like aurorae) and convert them to sounds. Light and sound are very similar from a physics standpoint — both are waves, though very different kinds of waves. Still, if you take the wavelength (color) and amplitude (intensity) of light, you can convert them mathematically to pitch and volume of sound. It’s not telling you anything physical or real, but it might give you insight into some phenomena… or it might just be cool, like this video which translates the March 7, 2012 solar storm into sound for your listening pleasure.
Nifty, isn’t it? And the big storm sounds like a lion’s roar, which is appropriate, at least. If you want more insight into this, Emily Lakdawalla posted about it, as did Universe Today. And check out the Related Posts below for links to more things like this.
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:
As for seeing them wherever you are, that’s tough to say. The Geophysical Institute has a map showing predicted activity for North America, for example, and NOAA’s Space Weather Prediction Center has a continuously updated map showing auroral activity for both hemispheres. Universe Today has a guide on how to see the aurorae, and Astronomy magazine has a discussion of aurorae, too.
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!