We take the Sun for granted. It’s there every day (unless you live in the Pacific northwest, of course), shining and warming us. But never forget: it’s a star, a mighty mass of churning ionized gas a million times the volume of the Earth. It’s complex, and surprising.
The latest surprise comes courtesy of the Ulysses spacecraft, currently in its 18th year orbiting and gathering data on our nearest star. One characteristic it keeps its eye on is the solar wind. This stream of subatomic particles blows off the Sun at hundreds of kilometers per second, flinging billions of tons of material into space every hour.
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| Ulysses measures the Sun’s magnetic field. Click for details. |
The solar wind changes over time, reflecting changes in the Sun itself. The magnetic field of the Sun has a 22 year cycle; it goes from minimum strength to maximum every 5.5 years, back to a minimum, then flips polarity (south becomes north and vice-versa), then strengthens again. This is what leads to the 11 year sunspot cycle — the number of spots depends on the strength of the magnetic field, which maxes out twice every 22 year cycle.
Obviously, this is complicated, and not terribly well-understood. Worse, the sunspot/magnetic cycle is different every time, with each period having different strengths, different characteristics. We’ve learned a lot about it, but some details are maddeningly vague.
And that leads to surprises, as I mentioned earlier. We’re at the sunspot and magnetic field minimum right now. That means the solar wind is also at a minimum, but for some reason yet unknown, this particular time the wind is weaker than usual. It’s speed is about the same as usual, but there’s only about 3/4 the usual density of particles in it, so the pressure the wind exerts is lower (think of it this way: a wave of water moving 10 km/hr can knock you over, but a wind at that speed feels gentle. Air is less dense than water, and so at the same velocity exerts less pressure).
What does this mean to us? To be honest, I don’t know. The Sun interacts with the Earth’s magnetic field in a highly complex way. The magnetic field of the Earth protects us from high-speed particles from deep space, for one. The solar wind compresses our field, so a weak wind means the Earth’s field extends higher. That means better protection for our satellites, which is nice.
But like I said, these interactions are complex. Could a weaker wind be somehow bad for us? It’s possible, but I’m not too concerned. We’re at the start of a new cycle; sunspots have been seen which means we’re on our way toward a max again in a few years (2013 or so). However, only a few spots have been seen, and they rapidly faded away. Something weird is going on in our nearest star, that much is certain.
Remember though, people have been around a long, long time, and have no doubt weathered such weirdnesses before. I don’t think our climate is necessarily at risk, or there will be any extinction level events! However, our society depends on electricity, and certainly our power distribution can be affected by solar events. So it’s a very good idea to keep our eyes on the Sun, and an excellent idea to try to understand it better.
[Not to belabor the point (but get used to it), I talk quite a bit about the Sun's effect on the Earth in Death from the Skies!]
September 26th, 2008 at 10:15 am
Oh my. I can hardly begin to imagine what the fear mongerers will pull out of this posting.
WE’RE ALL GONNA DIE!!! PHIL PLAIT SAID SO! OR AT LEAST SOMETHING TO THIS EXTENT! OR AT LEAST SOMETHING THAT COULD BE INTERPRETED AS A SLIM POSSIBILITY THAT SOMETHING COULD BE HAPPENING THAT COULD AFFECT US IN SOME UNCERTAIN TERM WHICH COULD MEAN … WE’RE ALL GONNA DIE!!!
September 26th, 2008 at 10:16 am
How can the Sun’s external expression of emotion be on the Earth? I’m confused. (Unless you meant the Sun’s effect, that is…)
September 26th, 2008 at 10:17 am
Imagine what could happen if a power outage affected North America! It could be the end of the World… of Warcraft…!
September 26th, 2008 at 10:23 am
Oh noes! You know what’s going to land in the vicinity of 2013? 2012.
Wait… this is an actual legitimate scientific phenomenon, so the chances of doomsday’ers using it as ammunition for their latest collective death-wish are pretty low.
September 26th, 2008 at 10:23 am
Phil, your posts are great to read everyday and I know you enjoy writing (and having us as your audience), but I anticipate one downside is having several hundred proof-readers endlessly picking and poking and nit-picking your creations. I suppose it is the price of popularity, huh?
Here’s one: In your last sentence you use the word “affect”, but I believe if I pressed, you would agree that “effect” is the word you intended.
September 26th, 2008 at 10:31 am
Not political. Not sarcastic. Just a question. Could this have anything to do with our current “climate change”?
September 26th, 2008 at 10:39 am
I don’t think it has any choice but to have an effect. The question is how large an effect?
September 26th, 2008 at 10:42 am
I have a question, does the variability of the suns output affect the amount of energy available as solar power? Or are the variations insignificant?
September 26th, 2008 at 10:43 am
Hey, now! We’ve got the sun every day here in the Pacific Northwest, too! It’s just that many days we’re protected from those dangerous cancer-causing rays behind a soothing layer of clouds.
September 26th, 2008 at 10:49 am
@ jasonB
Unlikely, since the solar activity Phil is describing is relatively recent compared to “our current climate change”, which has been observed for decades.
September 26th, 2008 at 11:00 am
You know what this means? We’re going to have to build a huge gold-shielded ship to carry a nuclear payload to the sun!
I don’t think it should have an observation deck though. Might not be too good for the crew’s mental health.
But seriously, this is very interesting.
September 26th, 2008 at 11:07 am
Hm, this strange behavior could create a mini black hole and fire it straight at the earth. The danger might be tiny to non-existent, we should shut down the sun to be safe.
September 26th, 2008 at 11:21 am
Phil: We’re at the start of a new cycle; sunspots have been seen which means we’re on our way toward a max again in a few years (2013 or so).
Or 2012!!!!! AAAIIGHHH!!!!
Peptron: Imagine what could happen if a power outage affected North America! It could be the end of the World… of Warcraft…!
So long as it’s back on by November 13th.
September 26th, 2008 at 11:25 am
@ RL
Some skeptics of global warming, including some scientists, have claimed that there may be a correlation between global warming and sunspot activity; however, there is insufficient data to confirm that hypothesis.
September 26th, 2008 at 11:26 am
Regarding climate change:
It’s important to recognize that we are talking about the solar wind here, particles from the Sun, not sunlight itself, which is the primary way energy is transfered to the Earth. I haven’t heard about any abnormalities in the Sun’s luminosity.
September 26th, 2008 at 11:27 am
Aside from how interesting what they represent is, I think that those are some incredible images on a purely visual level as well. Do you know anything about how they are captured? I’m assuming this isn’t the visual spectrum.
September 26th, 2008 at 11:27 am
There’s a sun-trend not mentioned–that the sun’s Meridional Flow has slowed to a crawl, when that happens the sun’s “output” has declined significantly and sunspots have been much much less numerous. The current Meridional Flow is reported to be the slowest observed in modern history — boding for very low sunspot numbers, etc. in the upcoming solar cycle. For meaningful details see: http://science.nasa.gov/headlines/y2006/10may_longrange.htm
Some good general overview info is available from NASA-Marshall Space Flight Center (MSFC) at: http://solarscience.msfc.nasa.gov/SunspotCycle.shtml
At the above sight, the apparent correlation with low sunspot numbers (& area as a percentage of the sun’s surface) is discussed, highlighted by the Maunder Minimum (also called the “Little Ice Age” from about 1645 to 1715, when sunspot counts were in the single digits per year, versus 150+ in recent decades).
Clicking on the butterfly diagram chart, or going to: http://solarscience.msfc.nasa.gov/images/bfly.gif
shows an interesting chart of sunspot activity as a percentage of area of the sun. Note that this value was below about 0.2 percent of the surface (versus between 0.2 – 0.5 percent) in the 1970s — which correlates the period in which those of us who were in grade- & high-school were being alerted to an impending ice age as temperatures seemed to be cooling (and this was when greenhouse gas emissions were still rising…).
A site that discusses the correlation between solar activity, sunspots & Global Warming is: http://www-das.uwyo.edu/~geerts/cwx/notes/chap02/sunspots.html
September 26th, 2008 at 11:37 am
P.S. The answer I gave above was meant for jasonB, but I think the same applies to RL’s question.
September 26th, 2008 at 11:38 am
Hey I live in the Pacific North West and we see the sun… well… “evidence” of it, I mean there is light out, it’s just a wee bit diffused through the white sky (the sky is white right?…), and… ah, who am I kidding.
September 26th, 2008 at 11:43 am
The sun is so often over looked in astronomy or in the sciences, especially in public communication of science. Cool to see some talk about it especially since we are at the bottom of the sun cycle and it is acting very weird. So much we don’t know about the celestial object we probably take most for granted.
September 26th, 2008 at 11:45 am
@ AndymanEC,
Sorry to say it but the Doom Squad has all ready been using the fact that we are expecting to hit Solar Max in 2012/2013 as part of thier universe ending Dec 12 2012 Mayan calendar death scenario.
September 26th, 2008 at 11:46 am
Our climate is at grave risk, and indeed is changing rapidly already and will continue getting worse for, at least, decades. Meanwhile, we are smack in the middle of the biggest extinction event since an asteroid smashed the earth 65 million years ago and did away with the dinosaurs (and pterosaurs, and plesiosaurs, and plenty of others).
However, neither the climate change nor the mass extinction is evidently a result of what is happening in the sun. Both are the result of profligate behavior by an irresponsible minority of a single species of animal that, curiously enough, depends entirely for its continued success on the undisturbed operation of the same climate and ecosystem it is disturbing.
It will not end well.
September 26th, 2008 at 11:57 am
The Sun does effect -MY- affect when it doesn’t present me with sunspots to look at! It’s been blank for seemingly years! I do like looking at prominences, but I want spots! Arrgh!
“So it’s a very good idea to keep our eyes on the Sun,”
Just so long as we use a solar scope and not our bare eyes like those nutjobs in India a few months ago. I used to say to schoolkids lined up at my solar scopes that nobody has ever actually been blinded by the sun because nobody was ever stupid enough to look at it as it hurts too darn much.
Now I stand corrected. :grumble:
Rich
September 26th, 2008 at 12:11 pm
The Sun is a mass of incandescent gas, a gigantic nuclear furnace. Where hydrogen is changed into helium at a temperature of millions of degrees.
There’s so much info about the universe that could be taught very easily if it were all just turned into TMBG songs.
September 26th, 2008 at 12:14 pm
Arrrrg, BUILT into helium. Difference there…
September 26th, 2008 at 12:30 pm
Nathan Meyers maybe you should look into taking some anti-depressants and anti-psychotics. Your life must be difficult being that afraid all of the time.
September 26th, 2008 at 12:37 pm
Too little data.
Um, if this is an extinction event, it is the first recognized as such since then, I think. The megafauna die off was AFAIU on quite another scale.
Projection is IIRC that anything between a few percent to some few tens of percent species lineages will die off, quite a far cry from earlier extinction events. But if it will become one, it may well be the fastest event; though I’m sure it is hard to tell due to the differences in measurements between observing it happen (species surveys) and observing it happened (fossils).
This is as far as I can see meaningless as stated, as it blend evolution and social processes into an amorphous mixture.
What happens in evolutionary terms (say, extinctions) isn’t measurable against a participating species (as a parochial social agent “responsibility”). In fact, as humans lives on and even has succeeded in becoming numerous it is evolutionary successful, and, arguably, as it thrives on extinction and also affect evolution’s main envelope it may be even more so.
Nor is species lineages success depending on a constant environment. The species may change and become more or less successful in numerical terms regardless if the environment changes due to drift and other effects, but a changing environment is fairly certain to change the species.
What happens in social terms is more vague, but there is a fair amount of analogy between evolutionary and social processes. With the risk of failure by analogy, I would think that social success is measurable in the same terms as evolutionary success – that is, it isn’t the species or the society’s unchanging “phenome” that is the basis for a measurement, but the continuance and numeracy of its “genomic lineage”.
[Longterm there should probably be something in there measuring success in terms of speciation and suchlike diversity as well.]
In that regard, the Homo sapiens (as a species lineage and a) society is currently a success, and is by that well positioned for the future in terms of robustness et cetera. It is just that it won’t be the same species or society in the future. But who cares? The likelihood for that was rather minimal anyway.
September 26th, 2008 at 12:39 pm
Robbie, Nathan is right.
Everyone else, Robbie is right … realism requires anti-depressants.
September 26th, 2008 at 12:39 pm
Oops! Maybe I should have refreshed first – Robbie calls on the BS so much more succinctly.
September 26th, 2008 at 12:43 pm
@ JasonB (and everyone else, of cours
)
The sun’s effect on climate change is not proven but there are some interesting things. BUT, as far as I know, these things were always like this:
A lack of sunspots (equal to a low activity of the sun) led to a decrease in temperature. One famous example is the “Maunder Minimum” in the late 17th century (check wikipedia on this!) when there were only VERY few sun spots for quite some time (50-60 years). Exactly at that time we had a “little ice age” with really cold winters. This could be a relationship – but it hasn’t to be!
Another thing about the solar activity is that (again as far as I know) there are two “opposing” theories about it. And one predicts that the upcoming maximum will be quite heavy while the other one predicts the exact opposite. We will see
September 26th, 2008 at 12:48 pm
Torbjörn Larsson, OM
The PETM killed 35-50% of benthic foraminafera. And the megafauna die off was indeed an extinction event. And there have been others. (Nathan did not claim were are in a mass extinction event.) You’re guilty of the ‘only the whoppers count’ fallacy.
September 26th, 2008 at 12:49 pm
Humans are not to blame for the mass extinction event (if it is happening) We have obsovered that Gorillas are developing heart conditions at an alarming rate, even in the wild. Many species of animals just stop mating, or their litters are smaller than in the past. The Permian mass extinction wiped out some 95% of all sea life and no one really knows why.
Also look at the Midevial warming period which was followed (within a decade) by the mini ice age. Climate change can occur over night and no one knows why, and blaming humans is very simplsitic.
September 26th, 2008 at 1:25 pm
I have a question – they talk about the sunspot record going back hundreds, even thousands of year.
How did they observe the sunspots back then?
September 26th, 2008 at 1:33 pm
This is a great post from Phil and I want to thank the people who provided the useful links to follow up on. The point of course is that we really don’t know. Whatever the sun/solar system/earth climate links are they are A) horribly complex and B) almost certainly unpredictable in principle. We likely are experiencing a number of conflicting climatological influences coming together — probably happens fairly frequently in earth’s planetary history — and who knows how that will play out. I do believe there is a possibility (note the word — no measure provided!) we are heading for a little Ice Age, but that is all I will say because A) it’s my nature to worry like that (I’m still working on the accelerating-expansion of the universe reducing the local night sky to a depressing and terrifying complete black) and B) I don’t want someone yelling at me that I am the equivalent of a vaccination denier for suggesting such.
I. Don’t. Know.
The economist in me says that as a society, the richer we are the better off we will be in weathering (not sure if that is the best word) what will come. This is particularly true given the nature and degree of the uncertainties involved.
September 26th, 2008 at 1:55 pm
I wish I had a nickel for every time somebody cited Wikipedia as an authoritative source.
Their motto: “the free encyclopedia that anyone can edit.”
Anyone, of course, except those with direct knowledge of the subject matter (”no original research” is one of their most cherished rules.) Wikipedia’s articles tend to turn into a mishmash of facts (often plagiarized from other sources), falsehoods (halos are the same things as rainbows!), and random gibberish, all stirred together by official “editors” who apply their own subjective bias to everything else. In time even the best-written article tends to fade into muddy static, like a stack of research papers turning into kipple, as divers hands spoil the broth.
Wikipedia is not an authoritative source, and should not be cited as proof of an position’s correctness or a statement’s validity. At best it should be used as a jumping-off point for further research.
Now…how do I set up a system for collecting a nickel every time somebody cites Wikipedia as an authoritative source? Maybe Wikipedia has the answer…
September 26th, 2008 at 1:56 pm
So it’s a very good idea to keep our eyes on the Sun,
Will we see virgin Mary, or some other saint?!
September 26th, 2008 at 2:17 pm
@Mus
No, but you might see it do the shimmy.
September 26th, 2008 at 2:36 pm
@Harold
“Anyone, of course, except those with direct knowledge of the subject matter (”no original research” is one of their most cherished rules.)”
You’re misconstruing that rule. The point of it is that Wikipedia is intended to be a tertiary source, whereas publishing original research would make it a primary source. It does not mean that experts can’t present their own findings in Wikipedia. It just means that they need to publish to a reliable source first, and only then should they summarize their results in Wikipedia, with the appropriate citation.
September 26th, 2008 at 3:49 pm
@Harold
I challenge you to find me two recent, unreasonable “falsehoods” in wikipedia which lasted more than 15 minutes. By “recent” I mean falsehoods which were on a wikipedia page within the last month (so a falsehood from 3 years ago doesn’t count), and by “unreasonable” I mean that nitpicky crap doesn’t count.
September 26th, 2008 at 4:09 pm
I think something just froze over because me and Nathan both think that what is happening to the sun has nothing to what is happening to the climate.
September 26th, 2008 at 4:12 pm
@Davidlpf
Next thing you know, you’ll be criticizing Phil for using “gas” instead of “plasma” in his description of the sun and Nathan will be saying that it was okay because Phil said it was “ionized gas”.
September 26th, 2008 at 4:13 pm
Two things
1) @ Harold:
I “cited” Wiki because for a quick check it is quite useful. Of course it is not a good source if you really want to proove something. It was my intention just to give a hint if someone doesn’t know what the “Maunder Minimum” is. I could have searched the entire web but I wasn’t in the mood for it. Now I’ve made a check at the NASA ADS page, searched for “Maunder” and found 200 results (and I guess there are more). Thus information is available. But I guess, wiki is not too false at this
2)
Here and there I hear or read that human beings are not to blame for global warming or the actual climate change. Well, maybe it is right that there is no proven link between the anthropogenic emission of “greenhouse gases” and the (proven) warming of our atmosphere.
But: Proven or not. We only have this ONE chance and we should not take it!
If you want to know where a runaway global warming leads to – well, take a look at Venus. In ancient times people thought Venus would be the “sister” of the earth. If we don’t care the earth will become like Venus, and then the ancient people were right at last.
September 26th, 2008 at 5:52 pm
What does this mean to us?
I know some ham radio enthusiasts, and I can tell you that they are gnashing their teeth over this recent sunspot cycle, and have been for quite a while now. (Apparently hams like sunspots, as they ionize the upper levels of the atmosphere, making it more reflective.)
September 26th, 2008 at 6:11 pm
From http://en.wikipedia.org/wiki/Halo_(optical_phenomenon)
Icebow
An icebow is phenomenon similar to a rainbow except that it is formed by the refraction of sunlight through cloud suspended ice crystals as opposed to raindrops or other liquid water suspended in the air. Generally the appearance is as arc sections as opposed to a full circle. Brighter sections usually occur above, below, and lateral to the center (where the sun is visible). These bright areas are referred to as “sun dogs,” “parhelia” (plural), or mock suns because of their bright appearance and possible confusion with the actual location of the sun. Those icebows that are caused by very small ice crystals are one colour, because diffraction blurs the colours together. A 22 degree icebow has red on the inside and blue on the outside.
Anybody want to take this one? My understanding is, an icebow can be considered “similar” to a rainbow except for little nitpicky details like how it is formed, where it is located, its geometry, and a few others. So it is “similar” in that it is round and sometimes shows colors in parts. And is made from the interaction of light and water (frozen flat ice crystals instead of spherical droplets of liquid). Other than that, completely different.
As for a second example…I don’t wanna. The content of the Wikipedia is constantly in flux, so stuff that chafed me last month may have been edited out already, and perfectly adequate entries may have meen modified or vandalized since I last saw them. Can anybody else come up with an example?
September 26th, 2008 at 7:19 pm
I know this is off topic, but since Venus was just brought up, I have wondered for quite a while now what would happen to Venus “IF” it were some how moved out to say the distance of Earths orbit.
I don’t know why but this question has been sitting at the back of my mind for a long time, I think since I first remember Venus being described as Earths “sister” planet when I was in grade school learning about the planets of our solar system, including Pluto.
September 26th, 2008 at 9:20 pm
MarkH, you might find this Wikipedia article interesting: Terraforming of Venus.
Harold, you’re entitled to your opinion, but… :-p
September 26th, 2008 at 9:31 pm
@Harold:
Is that paragraph what you were referring to in your original post? That is certainly not saying that “halos are the same things as rainbows!”, which is what you claimed in your first post. Of course, it could have been edited since you originally saw it, which is why I’m asking if it’s the same paragraph.
I completely disagree that calling rainbows and icebows “similar” is a falsehood (examples of falsehoods is what I challenged you to provide). Obviously the word “similar” is subjective, so I think you could argue that the article should be written in a way that doesn’t use that word, but that’s not a falsehood. I personally think it’s appropriate, but I can’t say I know all that much about icebows.
As for your reluctance to provide another example… well, if wikipedia is as bad/unreliable as you seem to think it is, it shouldn’t be all that hard to find plenty of examples. Simply going to a random article and clicking the links within it should quickly lead to “falsehoods” as you call them.
About the rest, I think you’re making my point for me. Wikipedia DOES potentially change very fast, and that is PRECISELY what makes it great. Vandalism and “falsehoods” are usually fixed very quickly, and new information can be added to articles as soon as it comes out. Static encyclopedias are often outdated, and if something is wrong (which it often is, since only a small number of people edit it), it takes a long time (relative to wikipedia) for it to be fixed. Sometimes the layout or wording may not be optimal (as the icebow example shows), but in my experience, wikipedia is quite accurate a high percentage of the time.
September 26th, 2008 at 9:39 pm
While my comment is awaiting moderation, I’ll try this again because it didn’t bloody work the first time.
Harold, you’re entitled to your opinion, but… :p
September 26th, 2008 at 9:42 pm
NUTS!
September 26th, 2008 at 10:33 pm
This is not the first time that this has happened. From Science, “The Day the Solar Wind Almost Disappeared”, 24 March 2000:
“On 11 May 1999, the number density of this “solar wind” decreased to remarkably low values (~0.2 particles/cm3, compared with an average value of 10/particles/cm3). A special session of the American Geophysical Union 1999 Fall Meeting (1) was devoted to discussing this extraordinary event and its consequences.” [Wow, scientists in a swivet! You've seen this movie.]
“‘Because the solar wind density was so low, the strahl electrons were relatively unscattered by collisions in the solar wind, and they arrived near Earth in an unusually intense and narrow beam that was able to penetrate into the polar region. The electron collisions with the atmosphere generated “the strongest x-ray emissions ever seen from the polar cap’ (D. Chenette, Lockheed-Martin, Palo Alto, CA).” [Neat! Strahl electrons! Look that up in your Wikipedia.]
“Although the density of energetic electrons in the solar wind returned to normal on the following day, the density of very high-energy electrons in the magnetosphere dropped once again the next day and remained severely depleted for nearly 2 months, despite the fact that the solar wind flux had returned to its usual value. This raises interesting questions about the refilling of the radiation belts.” [Sounds like a serious electron shortage. There's never a strahl electron when you want one.]
“Why periods of very low density wind occur remains unknown. It is interesting to note, as N. Crooker (Boston University) pointed out, that such low wind flux periods tend to appear on the ascending portion of the solar activity cycle, a period in which we are in now (2). Discussions of low solar wind flux periods will undoubtedly occupy solar physicists for years to come.” [Judging from this comment section, maybe even longer.]
I think the world ended which explains the mess we are in now.
September 27th, 2008 at 3:46 am
JohnW, it is possible to see sunspots with the naked eye under certain circumstances. It helps if the sunspots are fairly large. Not a recommended way of viewing. I have seen a large sunspot group without a telescope in 1999 or 2000. What helped was the thin layer of cloud which reduced the amount of light while not obscuring the sun too much.
I haven’t tried it but projection, in a similar way to viewing an eclipse, may also work. I’ll give this a try when it’s a) daytime and b) when there’s sunspots about.
October 22nd, 2008 at 9:23 am
[...] then happened upon this article about the sun’s protective bubble decreasing. Even Phil Plait from bad astronomy has no idea what this [...]