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An eruption from the Sun that happened today (youtu.be)
396 points by johnnytee on June 7, 2011 | hide | past | favorite | 78 comments

Very cool. Its amazing what we don't know about the star sitting just 8 light minutes away from us.

For jnorthrop generally these events are effectively deflected by the Earth's magnetosphere, however we don't know what we don't know. Its hard to estimate whether or not any one of the extinction events this planet has experienced over the past was caused by solar activity.

I would hope it would add impetutus to efforts to surviving large changes in the Earth's envioronment by creating completely controlled environments (ideally across several planetary bodies) but I have low expectations that it will.

One of the science stories I've been following for a while has been the growing body of evidence that a magnetic pole reversal [1] is becoming more likely. (Note there was a hoax around it changing instantly in 2012 which has been pretty thoroughly debunked). One thing that is pretty well understood is that during reversals the magnetosphere is greatly reduced [2] which suggests that the simulataneous occurence of a CME and a reversal of the poles resulting in a reduced magnetosphere would be something to write home about.

[1] http://www.nasa.gov/vision/earth/lookingatearth/29dec_magnet...

[2] http://www.off-ladhyx.polytechnique.fr/people/willis/papers/...

And you would have to write, unless there is significantly more tolerance in our digital network!

With large solar flares there have been reports of telegraph wires having such large currents induced that the telegraph paper caught on fire from the sparks generated! [1]

Just imagine what these currents would do to modern sensitive electronics... And I suspect that there hasn't been that much thorough testing in consumer-level hardware, although power and communication companies are very aware of the problems and have changed the designs of some systems to handle these events better (as in "let's not melt the power grid quite as bad...")

[1] http://science.nasa.gov/science-news/science-at-nasa/2008/06...

"The northern lights were unusual enough but then worldwide telegraph systems started going out. Telegraph operators were being shocked unconscious and the flying sparks from the telegraph machines were setting the papers and their machines on fire. When the telegraph operators disconnected their machines from the batteries, there were still sparks flying. This is because the power of solar flares induced electricity into the lines that carried the telegraph signals from one telegraph station to the next. This became known as the Carrington Event."



Kinda puts me off sitting here with my headphones on...

Early telegraphs didn't use a ground wire, the return path was literally the Earth. Modern systems with differential signals on a twisted pair are many orders of magnitude less affected.

I wouldn't think that most sensitive electronics is big enough to really be affected, you need a closed circuit that encloses a significant area. For the telegraph (and modern electrical grid) that would be the height that the wires are strung at times the length of the wires. Anything that fits in your home is probably safe, unless your network cables have shielding that's grounded at both ends with no series resistance or something.

The electrical disturbances don't need to be introduced into the electronics directly though - if the flare induced enough disturbance into the national grid, then all sorts of strange induced currents could appear on your mains voltage, and wreak havoc with inadequately filtered power supplies.

We rely on mains power to arrive at a nice even 50-60Hz, with the voltage varying a few percent. Sensitive electronics are designed to filter out this low frequency, but higher frequencies may well pass through into other circuits that weren't designed for it, with unknown consequences.

It'd likely fry transformers before they started detonating things in your home, though. The induced current on the path from the transformer to your house couldn't be that big.

Still, it's an interesting thought. With how fragile the power infrastructure is in North America, it could cause some serious problems.

In 1989 the Quebec province power grid was brought down for some hours following important solar activity. Like you said for consumers it was simply a black out. As for the power infrastructure I think they made important changes to make it more resistant (in Quebec), but I don't have more details.

What about optical technology? Would that be affected?

(yes, I know currently there is always at some electronical parts, but I mean in theory)

It's amazing what we don't know about things sitting just a few light seconds away at most, too, such as the depths of the oceans or the spiders in my backyard.

I think they're working on the 'bases on other planetary bodies' backup plan, but it will be a few years.

Just FYI, The circumference of earth is roughly 4 * 10^7 metres, and the speed of light is 3 * 10^8 m/s, so light can actually circle the globe almost 7.5 times per second.

The depths of the oceans are just a few milliseconds away (40ms -ish?).

I figured it was something like that. Certainly explains why my ping to London is under 100 ms, right?

Yup. My Telecommunications prof back in University told us you can approximate the speed of a network as 2c/3, so that sounds right on the button.



40 µs, not ms.

(off topic.. can anyone get wolfram alpha to answer that in one query?)

"Depth of Challenger Deep in light seconds"

I was going for the distance from some arbitrary spot in North America to some arbitrary spot way out in the middle of the Pacific Ocean, where I'd assume the ocean is at its deepest, but this is interesting too.

Damn, I read "One of the coolest eruptions from Sun you'll ever see. This happened today."

I was like finally, closures in java!

The Sun you mean is now a white dwarf inside a black hole. If you want to know when you might find closure, you need to ask an Oracle ;-)

I wish points were visible so I could see how many upvotes this got. Didn't point visibility get put to a vote by pg not long ago -- last I saw the "yes" votes were way ahead. (?)

Not sure which 'this' you're referring to, but my joke is now at 38 points. Does it really matter? They're just points. And don't worry, i'm still not able to downvote people :)

Was that a real-time video (i.e., shot and played at 1x speed)? If so, the matter appears to be traveling at roughly the speed of light. Greater, perhaps, indicating the video was sped up. http://www.wolframalpha.com/input/?i=diameter+of+the+Sun+%2F...

Edit… If you look closely (in HD), there are timestamps, suggesting this is being played at ~3600x, or one second of playtime representing an hour in reality.

I would have rather seen this video occurring much more slowly. It would have been more .. intense.

From that article it says "A good flare can release up to 10% of the Sun’s total energy" but they mean power, not energy, right? Because 10% of the sun's total energy released in that time frame would wipe us out, right?

Power isn't correct either, because power for how long.

I can't figure out what they mean.

I'd guess by '10% of total energy' they mean '10% of the total energy output in that period of time is released just in the area of the _flare_'

Correct. Flares can have an energy around the order of 10% of the total average energy output for the sun per second.



> A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 10^25 joules of energy[1] (about a sixth of the total energy output of the Sun each second).

Power is outside of the realm of time. P = E/t, so that's why I assumed power. For example, say the sun produces 384 yottawatts, that would be 384 yottajoules per second. Say the flare goes on for 6000 seconds and uses an average of 38 yottawatts, or 228,000 yottajoules over that time period (fun fact, yotta is where SI stops. Strange.)

There's been a movement for a while to add hella as the next SI prefix, for 10^27. It's already been adopted by Google and Wolfram Alpha, among others.

They yotta fix that!

The article doesn't say this flare is releasing 10 percent of the Sun's total energy. Instead it says:

"A good flare can release up to 10% of the Sun’s total energy, the equivalent of billions of nuclear bombs exploding. What’s funny to me is that this wasn’t all that big a flare; it was rated as a class M2.5, far lower in energy than the vast explosions from the Sun back in February."

It still doesn't make sense. The only way to interpret such a sentence is that the flare is releasing 10% of the Sun's rest-mass energy which of course is ludicrous.

I didn't say it made sense, merely clearing up the quote.

Forgive my ignorant question, but what if that eruption was aimed at us? Was that a mass ejection of something? If so, could that something have ruined the electronics in orbiting satellites or stripped our atmosphere?

Maybe I'm over-reacting but that appears to be an absolutely massive explosion.

This was a 'coronal mass ejection'. Inevitably, you're right - particles will no doubt make their way towards us.

These incoming particles will probably cause an increase in Northern/Southern Lights (Aurora Borealis/Australis). The earth has a 'Van Allen Radiation Belt' surrounding it - http://en.wikipedia.org/wiki/Van_Allen_Belt - which takes magnetically charged particles, often fired from the sun, and blasts them back down to earth. Upon impact with the planet's atmosphere, beautiful Auroras can be created.

However, satellites can't orbit anywhere nearby the Van Allen Belt, as obviously these radiating particles can damage sensitive instruments. I'd guess by the size of this mass ejection, a geomagnetic storm will be created. Wikipedia has a good list of the various negative effects of these things: http://en.wikipedia.org/wiki/Geomagnetic_storm#Geomagnetic_s...

Of course, it depends on the direction the eruption was aiming as a primary factor. This wonderful image - http://en.wikipedia.org/wiki/File:Magnetosphere_rendition.jp... - shows a perfect example of the Van Allen Belt. If you tip your head 90 degrees to the left, it kind of looks like an angel around earth - the 'halo area' is the main Van Allen Belt loop causing Auroras by firing the particles towards each polar cap.

(Disclaimer: I have an interest in astronomy, but nothing to put to my name except for a B-grade Astronomy GCSE - it's likely much of that explanation is scientifically inaccurate, but, I tried my best! :)

If you tip your head 90 degrees to the left, it kind of looks like an angel around earth - the 'halo area' is the main Van Allen Belt loop causing Auroras by firing the particles towards each polar cap.

That reminds me of the passage in the Bible claiming four angels standing at corners of the earth. Not to get into a theistic thread or anything, but who needs religion when science is that stunning? Beautiful imagery!

Yeah, but it's going to take science a while just to find the corners on the earth. ;)

It takes a liberal arts major about a second to find the metaphor. ;)

Shh! I was trying not to point that out ;)

I'm assuming the video was taken from somewhere in the vicinity of Earth, so it doesn't look like it was aimed anywhere near us. We'll likely see some increase in solar particles, but not nearly as much as whatever was directly in its path.

It takes on the order of three days to reach Earth.

Probably not much. According to the blog, this was a lower-energy explosion than, say, this one[1], which was aimed right at us.

[1] http://www.youtube.com/watch?v=himC51J23vQ

Flares and CMEs can certainly cause damage to electronics or to astronauts.

It is believed that the CPU outage that caused the loss-of-pointing of the Galaxy IV satellite that in turn caused the giant pager outage in 1998 (about 80% of US pagers failed) was due to solar flares and CMEs.

It's also conjectured that flares cause many other satellite electronics failures:


The general phenomenon is called "Space Weather".

There is a monitoring center in Boulder, CO, run by NOAA, called the Space Weather Prediction Center (http://www.swpc.noaa.gov/), that tries to predict and assess space weather. They use physical models and observational data, but it's not nearly as evolved a science as numerical weather prediction.

For nice current images of the Sun, the Proba 2 satellite [1] continuously watches it and dumps some nice imagery/movies. It's ESA sponsored, and both it's sensors (SWAP producing the visuals) are interpreted by the Belgian Royal Observatory. Iirc the Belgians and the Canadians are the only ones keeping a close eye on the sun, counting sun spots and such. Makes for a nice desktop bg also!

[1] http://proba2.oma.be/index.html/

If you want exquisite solar desktop images, the place to go is:


These are from the Swedish Vacuum telescope on La Palma (Canary Islands). This instrument currently offers the highest-resolution solar images anywhere.

The images shown on that page show many convection cells, called the solar supergranulation. Each cell is about the size of Earth.

What you say about who's keeping an eye on the Sun is not the case. In addition to the Swedish telescope above, the Japanese have an excellent high-resolution imager (in orbit) called Hinode, and there are multiple US space imager including SDO and Stereo, plus many terrestrial telescopes.

maybe I'm misinterpreting what you're saying, but this event happened today, so it's pretty current. You can also get "the sun right now" at the SDO site[1], and it looks like they update those every 15 minutes.

There are also several probes that are keeping a close eye on the sun these days, from the more venerable SOHO to the newer STEREO probes and now SDO, of course.

[1] http://sdo.gsfc.nasa.gov/data/

I wish there was a way on HN to easily find out submissions that have videos in them. Often times, especially when I'm eating at my desk, I'd rather watch interesting videos than read articles, and such a feature would be of great help on HN.

Maybe there's a way that you guys know of (besides reading cues from the title)?

The standard convention is to put [video] in the title - a convention which is sadly being ignored here, along with the inexplicable use of a URL-shortener. It should be possible to locate all submissions so marked as videos with HNSearch (it's down at the moment, for some reason, so I can't verify this).

EDIT: HNSearch is back up, searching for "[video]" or "video" in stories seems to show only links to videos on the first page when sorted by relevance, 8 out of 10 results when sorted by points, and 9 out of 10 when sorted by date.

Thanks for the tip!

You could possibly use the HNSearch API or HN Firehose Twitter feed to get all the top stories, then check their target URLs for common video types.

http://crowdtube.tv aggergates reddit and delicious.

The shockwave is expected to reach earth around 1 pm EST tomorrow (5pm GMT), auroras are likely to follow after that and they should be visible quite far south.


You'd have to line up 100 Earth's end-to-end to fit inside the Sun. This was reportedly about the size of the Sun itself, so it would engulf 100 Earths. It would probably destroy more since even planets on the periphery would have all life destroyed.

It's big, but it's also dilute. It would not destroy any planets even if they were right inside it.

This statement, taken literally, is absurd. What are you trying to say?

...that he's absurd. I'm pretty sure exposing our troposphere to 6000K would hurt a little.

It would do nothing. We expose the atmosphere to 6000K every day in forges and nothing bad happens.

The reason of course is the temperature doesn't matter - total energy does. And even though it's very hot, and very large, there is very very very little matter there, so the total energy is quite minimal.

Might be interesting to watch this over the next few days - http://www.gi.alaska.edu/AuroraForecast

Is this sped up?

Yes. I couldn't see it at first, because of the advertising overlay, but there is a time readout in the lower-left of the video.

It looks like it's sped up about 60x.

Is anyone able to slow this down? I realize they wanted an explosion effect but it goes too fast for me.

  youtube-dl -o sun Hyi4hjG6kDM # [1]
  mplayer -speed 0.25 sun
[1] http://rg3.github.com/youtube-dl/. It's available in the Arch Linux and Ubuntu repositories, as well.

get_flash_videos[1] covers more sites and has a plugin infrastructure, though I haven't personally written a plugin.

[1] http://github.com/monsieurvideo/get-flash-videos

According to one of the comments on the blog, the video frames come from Helioviewer: http://helioviewer.org/?date=2011-06-07T07:20:00.000Z&im...

The whole explosion takes around three hours.

you mean 3600x. It looks to me like it's ticking the hours past at about one a second.

I thought the title meant that an executive from (the now nonexistent) Sun Microsystems lost his cool.

First reaction: that's it?? Second reaction: wait, this was big enough to engulf the Earth. Cool!

Although not the flare from today, here is an image that has the earth shown against one of these eruptions for scale: http://www.nasa.gov/images/content/515512main_prominence_Ear...

Honestly, when we start talking about these huge distances and the vastness of space, the scale of things just seems to lose all meaning. Maybe it's because most of us are engineers and these sorts of numbers only exist in our heads in abstract terms, but I find that I really have to look around me and ground myself in relative terms before I can fully grasp how mind-bogglingly huge that is.

Until about the middle of February it looked as if we were going to maybe catch a break on global warming as the Sun's output was down significantly and the possibility that a Maunder type solar minimum was occurring was increasing.

About 2/15/11 solar output started getting back to more normal levels.


Too bad, we could use a break.

the sun divided by 0

what simulator do they use?

so that's why skype crashed this morning... :P

Call me paranoid, but that just made my stomach drop.

Why so? You most likely have lived through larger solar eruptions without knowing it.


Didn't hear a thing.

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