Tag: coronal mass ejection

Will you see the lights tonight?

By Phil Plait | January 24, 2012 11:45 am

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:


Fairbanks, Alaska

Yellowknife, Canada

Tromso, Norway

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!

Related posts:

The Sun aims a storm right at Earth: expect aurorae tonight!
Time lapse: The Aurora
JAW DROPPING Space Station time lapse!
Stunning Finnish aurora time lapse

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

The Sun aims a storm right at Earth: expect aurorae tonight!

By Phil Plait | January 24, 2012 6:00 am

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.

Although big, this flare was classified by NASA as being about M9 class — powerful, but not as energetic as an X class flare. One of those popped off last September, and shortly after that a smaller M flare erupted, which also triggered a gorgeous plasma fountain called a filament on the Sun’s surface.

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.

Image credit: NASA/SOHO; NASA/SDO

Related posts:

Awesome X2-class solar flare caught by SDO
Gorgeous flowing plasma fountain erupts from the Sun
NASA’s guide to solar flares
The comet and the Coronal Mass Ejection

The comet and the Coronal Mass Ejection

By Phil Plait | October 4, 2011 9:30 am

On October 1, a bright comet screamed into the Sun, and apparently disintegrated. This happens pretty often, actually, but in this case, just minutes later, the Sun blew out a pretty hefty coronal mass ejection, a huge explosion of magnetic energy that can release billions of tons of material.

Some people have speculated that these two things are related (including times when this has happened in the past). Are they? We have videos of the event from three different satellites, giving us three angles on what happened, providing clues on what really occurred.

To shed some light on this — haha — I made a short video explaining this, including the footage of the comet collision and CME as seen by the three satellites:

[It helps to set the video resolution to 720p to see the details in the satellite views.]

So my guess is that while it’s possible, it’s not probable. CMEs happen all the time, so I’d expect a few to happen around the same time as comets flying past the Sun just by coincidence. We don’t have any physical reason to think they’re related, and when they are examined more closely, the CMEs usually don’t come from a spot near the Sun where the comet traveled. Still, it’s worth looking into, at least to build up a statistical case on way or the other.

The folks at SOHO — the Solar Heliospheric Observatory — have a post up with more info. Also, if you want to see the three satellite videos on their own, here is the SOHO video
the STEREO A video, and the STEREO B video.

Very special thanks to SungrazerComets on Twitter for making the three original satellite animations. That’s a good stream to follow if you want the latest on comets making death dives onto our star. [UPDATE: @SungrazerComets just posted an excellent and thorough article about this topic, too!]

Image credits: NASA, SOHO, STEREO

Related posts:

Amazing video of comet on a solar death dive
The Sun blasts out a flare and a huge filament
Solar storm tracked all the way from the Sun to Earth
STEREO sees an ethereal solar blast

Solar storm tracked all the way from the Sun to Earth

By Phil Plait | August 20, 2011 7:00 am

Yesterday I wrote about scientists being able to see sunspots as they form deep inside the Sun, well before they rise to the surface.

Around the same time, more news about the Sun was released as well. And I was ready to write up a fancy schmancy post talking all about it, I really was. It would be about how my old friend Craig DeForest used data from NASA’s Solar TErrestrial RElations Observatory (aka STEREO) to track a coronal mass ejection (CME) — a huge blast of subatomic particles chock full o’ magnetic energy — all the way from the solar surface to the Earth… but then those folks at NASA’s Goddard Space Flight Center put together this terrific video explaining it really well, saving me the effort!

Very very cool. Here is a still from the actual animation of the blast:

[Click to embiggen.]

In this graphic, the Sun is on the right and the Earth on the left. The horizontal scale is logarithmic, which means it’s highly compressed; as you get farther away from the Sun (that is, looking more to the left) the step size gets bigger. That allows a lot of space to be shown in a relatively small graphic. The green arrow shows the location of the CME, still well before it hit the Earth (if you click to get the complete image, you’ll see several frames as the CME headed our way; the planet to the right of Earth is a representation of Venus).

It’s hard to overstate just how faint this thing is; it took a huge amount of detailed processing to tease out the weak signal from the much brighter background of stars, the Milky Way, and other sources. Now let me phrase this next bit carefully. I know a lot of scientists, and many of them are the best of the best. Geniuses. I’ve known Craig for a while now (we used to work down the hall from each other at Goddard), and so when I tell you he is among the smartest people I have ever met, then hopefully you will understand the full import of this.

So this work is fantastic. Not only is it really beautiful and simply cool, it is also very important. A big CME carries a heckuva whallop with it, and can damage or destroy satellites and cause blackouts here on Earth. Nailing down their arrival times is extremely important, and has always been difficult. Craig’s process using STEREO data can potentially reduce that uncertainty, and in the process save a lot of cash and grief. In this game, minutes count.

As the Sun ramps up its activity toward the peak in 2013 and 2014, this technique, and STEREO itself, will come in handy, I’d wager. But then, that’s why we do this stuff!

Related posts:

STEREO sees an ethereal solar blast
One piece of solar flare
STEREO scoping
The whole Sun catalog

CATEGORIZED UNDER: Astronomy, Cool stuff, Science, Top Post

Sun blows out another big one, expect aurorae tonight!

By Phil Plait | August 5, 2011 5:00 am

On August 4 at about 04:00 UT, the Sun let loose with another big flare, this one ranking as an M 9.5 or so on the standard flare classification, bigger than the one earlier this week. It also triggered a coronal mass ejection, which means we may get some effects here on Earth.

First, the way-cool video:

[Set the resolution to 720p or 1080p for the best view. Note: In the video title I said this happened on August 3. It did, in my time zone! It was August 4th in Universal Time, however. Sorry about any confusion.]

This is in the far ultraviolet, where energetic events like these show up well. The bright regions are actually sunspots, which are dark to our eye but are pretty glowy in the UV. At 03:57 UT the magnetic field lines in the spot reconnected, starting a cascade that released all the energy they contained. This caused the flare that’s fairly obvious in the video. But you can also see material blasting away from the area, some falling back down. Finally, there are wispy tendrils of material arcing up that fade away.

What you don’t really see here (but SpaceWeather has an animated GIF of it) is that this also sparked a coronal mass ejection (CME), a much larger explosion of energy that blasted roughly a billion tons of subatomic particles away from the Sun at the terrifying speed of nearly 2000 km/sec (1200 miles/sec). The energy involved in an event like this will crush your sense of scale to dust: it’s the equivalent of the detonation of 500 million one-megaton nuclear bombs.

Of course, the 150 million kilometers between us and the Sun is a pretty big buffer. As the CME expands the energy spreads out a lot, and by the time it reaches here it’s much weaker, though still significant. Now, don’t panic: this happens a lot, and generally isn’t too big a deal to us on the ground. This flare and CME were big but not nearly as big as the Sun can put out. However, it is expected this material will hit the Earth’s geomagnetic field sometime today, probably around 14:00 UT (10:00 a.m. Eastern US time). If it does, it will probably spark aurorae at high to medium latitudes. I live in Boulder, so I’ll be out tonight looking for them. You can check the NOAA Solar Weather page to see if you are inside the expected region to see the northern lights from this.

I doubt we’ll see many satellite or cell phone problems from this, though it’s possible. This sunspot (technically named Active Region 1261) still seems pretty agitated, so we may yet see more from it. It’s rotating to the opposite side of the Sun, though, so it most likely won’t do anything to us after this.

… but, as I’ve been pointing out, we’re at the start of the solar cycle. It won’t peak until 2013 or so, and it’s around then we’ll probably see the big fireworks. Again, we probably won’t be affected here on Earth — in 2003 we had some huge events, and we survived — but brownouts and damage to satellites are always possible. I’ll be keeping my eye on all this, and you’ll hear about it as soon as I do.

Related posts:

The Sun lets out a brief flare
The Sun lets loose a huge explosion
STEREO sees an ethereal solar blast
INCREDIBLE solar flare video

SDO's first year in space with bonus voting

By Phil Plait | April 26, 2011 7:00 am

NASA’s phenomenal Solar Dynamics Observatory has spent just over a year in space. During that time it has ceaselessly observed the Sun, returning incredibly detailed and exquisite images and videos. In high resolution we’ve seen sunspots, flares, coronal mass ejections, filaments, prominences, and towering loops of magnetic plasma.

To celebrate, the folks at SDO put together this video featuring 12 of their favorite clips. I’ve written about several of these myself in the past year (see Related Posts below). Make sure you set the resolution to 720p!

You can go to the SDO page to get a list of what you’re seeing.

In a related bit of news, NASA is asking people to vote on their favorite short video from SDO. Many of those clips are also in the above video, but they’re also listed separately on the NASA contest page. I know which one is my favorite… but I’m not telling.

The voting closes May 5th.

Related posts:

When the Earth takes a bite out of the Sun
An eclipse from space with a two-way Moon
kaBLAM! Footage of the X-class solar flare
Sunspot 1158 ain’t done yet
First earthward-heading solar flare of the cycle
The birth of sunspot cluster
Arc of dissent
A huge lopping prominence on the Sun
The Sun blasts out a flare and a huge filament
SDO lunar transit: now with video!

STEREO sees an ethereal solar blast

By Phil Plait | April 18, 2011 5:25 pm

On March 19, 2010, the Sun’s magnetic field erupted, launching a billion tons of plasma into space in an event called a coronal mass ejection. This particular CME headed right for Earth, but had no effect on us (except perhaps sparking some aurorae). It was captured from the side by NASA’s STEREO spacecraft — actually, two spacecraft, labeled A and B, which are far ahead and behind the Earth in its orbit around the Sun. A pretty nifty video of the STEREO A observations of this CME has just been released:

[Note: I suggest upping the resolution to 1080, and then making this full screen.]

The Sun is off to the right, and you can see the loops and glow from the plasma as it left the Sun at high speed — about 350 km/sec (210 miles/sec). That’s fast enough to reach us here on Earth in about 5 days. And yup, those are stars you’re seeing in the background. At the distance to the CME, the scale of the video is about 48 million km (30 million miles) across.

On its way to Earth, this CME plowed past a satellite called ACE, designed to study subatomic particles ejected by the Sun (as well as from galactic and extragalactic sources, too). This means that CMEs like this one can be studied as they erupt, have their internal structures traced as they expand, and then studied as they impact us as well. As more are observed, we’ll learn about how these giant eruptions are formed, and what impact they have on Earth.

The goal too is to understand them well enough to be able to predict their impact on us. A big CME can damage satellites and cause power grid outages on Earth, which can result in billions of dollars in economic loss. If they can be accurately predicted, it can potentially save us a lot of grief.

Video credit: Anthony Williams / NASA / Richard Harrison

Related posts:

kaBLAM! Footage of the X-class solar flare
The whole Sun catalog
The Sun blasts out a flare and a huge filament
The Sun rises again

CATEGORIZED UNDER: Astronomy, Pretty pictures

Bad Universe Episode 3 airs Tuesday April 19

By Phil Plait | April 18, 2011 7:00 am

Well, it’s been a while coming, but I’m pleased to let y’all know that the third and final episode of "Bad Universe" will air on The Discovery Channel tomorrow, April 19, at 11:00 a.m. Eastern (US) time — but of course, check your local listings.

The episode is entitled "Death Stars", and is about the effects of solar flares and nearby supernovae. Like the other two, this was a lot of fun to put together, though the trip to Sandia Lab still haunts me a bit… but I won’t give that away. You’ll just have to see. I actually haven’t seen the final cut since we put it together late last year, so to be honest when I watch it tomorrow it’ll be a bit like seeing it again for the first time.

Speaking of which, my daughter will be in school when it airs, so I won’t watch it until we can see it as a family. That means I won’t be live-tweeting or anything like that.

And to answer the inevitable question: I don’t know if the network is picking it up as a series or not. I expect the ratings of the airing tomorrow may play into that, so tell a friend! Or tell a few dozen.

I hope you like it, and have at least as much fun watching it as I did making it.

CATEGORIZED UNDER: Bad Universe, TV/Movies

kaBLAM! Footage of the X-class solar flare

By Phil Plait | February 17, 2011 11:06 am

NASA’s Solar Dynamics Observatory has a nice video of the solar flare and coronal mass ejection from February 15th which I uploaded to YouTube:

[More formats are available at NASA’s SDO site.] Whoa! We’re in no major danger from this event, but wow, that’s cool. So what did you just see?

As I described in an earlier post, Sunspot 1158 is an active region on the Sun, with a lot of magnetic energy stored up. That energy got released with a bang on Tuesday, creating a solar flare — essentially a magnetic bomb on the surface of the Sun — and a coronal mass ejection (CME) — a huge eruption of subatomic particles blasting outward from the Sun.

The flare can be seen as the sudden bright flash just below and to the right of the center of the Sun’s disk. At the same time you can see an expanding circle of light centered on the Sun. That last bit is the CME. We see these launching off the Sun quite often; usually headed off to the side, looking like a big loop or light-bulb shape moving off. When they head straight Earth, though, they look like a circle that expands as it approaches. That’s how you can tell we’re in the way!

As I mention in the other post (and in Chapter 2 of my book Death from the Skies!), flares and CMEs can present a real danger to Earth, though this particular event wasn’t too worrisome. The most likely outcome is some disruption in radio communications, but more happily it also means potentially intense aurorae, northern and southern lights. SpaceWeather.com is always a good place to look for images of these beautiful events. There may be some aurorae tonight from this event, in fact. The NOAA Space Weather Prediction Center posts aurora maps, so you can see if you live in an area that might be treated with these eerie and literally unearthly lights.

Related posts:

Sunspot 1158 ain’t done yet
The green fire of the southern lights
One solar piece of flare
A HUGE looping prominence on the Sun!


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