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Solar Flares Shield Astronauts from Cosmic Rays

samzenpus posted about 9 years ago | from the not-so-fantastic-four dept.

Space 135

It doesn't come easy writes "Considering all of the research into better shielding for astronauts, it's interesting to note that solar flares can help shield space travelers from dangerous cosmic rays. From the article: "The crew of the ISS absorbed about 30% fewer cosmic rays than usual [during this last month of high solar activity]," says Frank Cucinotta, NASA's chief radiation health officer at the Johnson Space Center. "The storms actually improved the radiation environment inside the station." Scientists have long known about this phenomenon. It's called a "Forbush decrease," after American physicist Scott E. Forbush, who studied cosmic rays in the 1930s and 40s. So, I guess it would be safer to plan a manned Mars mission to coincide with peak sunspot activity?"

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hmmm, matter absorbing energy? (0)

Anonymous Coward | about 9 years ago | (#13778154)

Novel concept.

Yes, AND... (1)

game kid (805301) | about 9 years ago | (#13778184)

...magnetic fields from flares and CMEs (this "matter" you speak of) deflecting the energy, too. Don't forget that.

Re:hmmm, matter absorbing energy? (2, Interesting)

ccarson (562931) | about 9 years ago | (#13778279)

Apparently, the Earth magnetic field has decreased by 10% in the last 10 years. I'm an electrical engineer and during my studies in sub-atomic physics, I learned that a particles velocity can be effected by magnetic fields. I keep hearing about the increased activity of our Sun and I believe it's possible that more of the Sun's radiation is penetrating the Earth's magnetic field due to it being weaker. If more radiation hits the Earth and the Sun is spewing out more heat, shouldn't that also increase the overall temperature of the Earth and can global warming be attributed to this? I've been bouncing this idea in my head for a while now and I can't see why this MAY not be true.

Re:hmmm, matter absorbing energy? (1)

SteveAyre (209812) | about 9 years ago | (#13778628)

Every few thousand years the Earth's poles shift. From various volcanic rocks we can see how often it happens and it's a very regular occurence, every few thousand years.

The people looking into it have already noticed the field is weakening and has been for hundreds of years. The rate at which it gets weaker will also get faster and faster until it collapses entirely.

I think it's due to completely collapse in 500-1000 years or so, before growing again but the other way around.

You're right about deflecting the particles though - while it's collapsed the Northern Lights'll be visible from as far south as London and I think Paris and the extra radiation exposure will probably mean cancer rates skyrocket.

Re:hmmm, matter absorbing energy? (1)

SteveAyre (209812) | about 9 years ago | (#13778664)

Lots of results on Google.

Turns out that the last time was 780000 years ago. It's not very precise but they usually happen every 250000 years so we're *long* overdue for it. And it does appear to be happening now, so the flip will slowly happen over the next couple of millenia.

Some scientists aren't so sure it is going to flip though, as the past 2000 years have seen it just about the highest it's ever been, so it might just be returning to a reasonably normal level.

The reason it flucuates so much by the way is it depends where the rocks in the core are. Because they're all molten, they flow and move around. Some parts are North poles and some parts are South poles so the overall poles shift as they move around. I remember someone modelling these movements on a computer and that model said it would collapse over the next 1-2 millenia.

Re:hmmm, matter absorbing energy? (1)

stuffduff (681819) | about 9 years ago | (#13778586)

Energy becomes matter.

Shields up (4, Interesting)

cy_a253 (713262) | about 9 years ago | (#13778168)

So, I guess it would be safer to plan a manned Mars mission to coincide with peak sunspot activity?"

How about having the spacecraft generate its own external magnetic field? How effective would that be?

Re:Shields up (2, Interesting)

Anonymous Coward | about 9 years ago | (#13778226)

A better shield would be composed of something that is rich in hydrogen, as high velocity charges particles like those in cosmic rays will lose their energy as they intereact with the protons in the hydrogen atoms.

Eventually, when we get to the point where we're building ships in orbit (where mass will be less of an issue than it is when you're launching it all up from Earth), you'd likey be building a vehicle out of more durable materials (mmm, cermets), with a good layer of the previously mentioned hydrogen rich material, most likely a plastic of some sort.

Magnetic fields would add to this protection for lower energy particle radiation, but sometimes they can make such hazards worse by accellerating the particles further. However, done correctly, they could provide a little extra protection, while at the same time giving you a nifty propulsion system in the form of a magnetic sail.

Re:Shields up (0)

Anonymous Coward | about 9 years ago | (#13778282)

A better shield would be composed of something that is rich in hydrogen, as high velocity charges particles like those in cosmic rays will lose their energy as they intereact with the protons in the hydrogen atoms.

Two words: Ion drive.

Of course, you'll still need some other shielding for the rest of the vessel.

Re:Shields up (1)

mOdQuArK! (87332) | about 9 years ago | (#13779590)

with a good layer of the previously mentioned hydrogen rich material, most likely a plastic of some sort.

How about water? It's going to be important for other reasons anyway.

Re:Shields up (1)

Lucractius (649116) | about 9 years ago | (#13779807)

water is much heavier than long chain hydrocarbon polymers per unit volume and gives a bit more hydrogen there too

Re:Shields up (1)

Lucractius (649116) | about 9 years ago | (#13779818)

for those reading... i made a minor error writing that.

the long chain hydrocarbon polymers provide more hydrogen, not water.

stupid grammar.

1/r^2 kills this (4, Insightful)

G4from128k (686170) | about 9 years ago | (#13778360)

The Sun's magnetic field [astronomycafe.net] may be very weak (about 5 Gauss at the surface, about 0.00005 Gauss in solar wind), but it's very big. Creating a field with a compact object (say 100 meters in diameter -- quite a large space craft!) that creates a 0.00005 Gauss field at a distance of 160 million kilometers would require a field strength on the order of about 1.28 x 10^18 Gauss. This is NOT compatible with living things. Fields stronger than 100,000 Gauss can levitate living things [science.ru.nl] . I suspect that the needed deflector field would strip the electrons off the spacecraft's atoms (even a 200,000 gauss magnets have a tendency to explode).

Even if I'm off by many orders of magnitude (IANAP), the required field strength will be unattainably high.

Re:1/r^2 kills this (4, Interesting)

mattjb0010 (724744) | about 9 years ago | (#13778485)

Fields stronger than 100,000 Gauss can levitate living things.

I've stuck the movie of the levitating frog up here [adelaide.edu.au]

Re:1/r^2 kills this (1)

JoaoPinheiro (749991) | about 9 years ago | (#13778560)

Thank you! :)

Re:1/r^2 kills this (1)

deglr6328 (150198) | about 9 years ago | (#13778918)

I can't help but wonder just what kind of super-psychidelic-freak-out that frog must be having. First off, it is experiencing weightlessness, a phenomenon so outside of its natural environment that that alone must be super-freaky for it, especially without the ability to comprehend how or why it is happening like humans can. Second, it is immersed in a super strong 20 Tesla magnetic field and it's bouncing around in there like crazy, the resultant electric currents induced in the neurons of its brain must be quite an experience to be had. Sometimes people who are rolled into a 3T magnetic field in an MRI machine complain of dizzyness. Imagine what this little froggy must be feeling! :oD! or maybe its more like :-x :-[[

Re:1/r^2 kills this (1)

Lucractius (649116) | about 9 years ago | (#13779889)

any video of the exploding magnets??? :D

Re:1/r^2 kills this (5, Informative)

barawn (25691) | about 9 years ago | (#13778684)

Nope.

The fact that the Sun's magnetic field is large isn't what protects us from cosmic rays. The Sun's magnetic field encourages particles to orbit the Sun. That doesn't help us. What helps is when a dipole field gets closer to you - like when the Sun sloughs off a bunch of plasma that drifts near you. Hence a Forbush decrease. What protects us on Earth is the Earth's magnetic field, and the atmosphere.

Anyway, it's relatively easy to craft magnetic fields to any shape you want. So high magnetic field on the outside, zero magnetic field on the inside. We're really good at that. And 5 tesla (50,000 gauss) should be about enough [thespacereview.com] . It has been studied.

The reason it's not ideal is because cosmic rays aren't all charged. Gamma rays make up a component of solar cosmic rays, and okay, there may (should) be a few neutrons from the Sun as well (though that part is really new and not well studied).

But magnetic shielding is very actively being looked at. It's just not an easy problem - we don't have very much experience with superconducting magnets in space, for instance.

Interestingly, one of the best things about this is that you don't really have to worry about the highest energy particles which will get through. Not only is the flux far, far lower, but they deposit less energy than lower energy particles which stop in your body. So it's pretty easy to figure out how high a magnetic field you need.

And smartass comment: magnetic fields don't drop like 1/r^2. Electric fields do. For a simple magnetic dipole, the field strength drops like 1/r^3. Different configurations drop differently, as well.

MOD PARENT UP (1)

G4from128k (686170) | about 9 years ago | (#13778763)

If I could transfer my mod points from my post to yours, I would. Thanks for the info.

Re:1/r^2 kills this (1)

deglr6328 (150198) | about 9 years ago | (#13779108)

"The reason it's not ideal is because cosmic rays aren't all charged. Gamma rays make up a component of solar cosmic rays, and okay, there may (should) be a few neutrons from the Sun as well (though that part is really new and not well studied)."

That doesn't sound quite right. Why would free neutrons (half life 15 minutes) be an issue coming from the sun? Besides, fusion does not occur to any appreciable degree in the corona, it only occurs deep within the inside of the sun, neutrons produced this way would be fully shielded from escaping. Also gamma rays from the sun are not an issue, the moon is brighter [wikipedia.org] than the sun in gamma rays. Perhaps you are thinking of neutrinos, in which case that is also a non-issue as neutrinos only interact via the electroweak force and can thus pass through millions of miles of solid lead without interacting.

Re:1/r^2 kills this (1)

dominux (731134) | about 9 years ago | (#13780046)

a half life of 15 minutes means just that, half of them will decay in the first 15 minutes. Half of what is left will decay in the next 15 minutes. The sun is 8 light minutes away from us, If the neutrons go at a speed of about c/2 then half will get here. An hour after departure there will be 1/16th of the neutrons left. The inverse square law also applies as they will be getting more spread out radially. Assuming constant speed, combining the halflife decay and the inverse square I think the decay is proportional to something like 1/((2^r)*(r^2)) but I might be wrong.

Re:Shields up (3, Interesting)

shokk (187512) | about 9 years ago | (#13778459)

You mean like a hot hydrogen plasma confined in a toroid shaped magnetic field similar to what they use for fusion research? Maybe it doesn't need to be quite that hot to protect the astronauts, but keeping it moving around the outside of the craft may produce the same benefit.

Re:Shields up (0)

Anonymous Coward | about 9 years ago | (#13779174)

The M2P2 experiment used a plasma-inflated magnetic bubble for both propulsion and shielding. Shielding concepts for a lunar base and space station were proposed.

http://www.ess.washington.edu/Space/M2P2/ [washington.edu]

How about a change in human biology? (0)

Anonymous Coward | about 9 years ago | (#13778619)

To create stronger magnetic fields, or just better repairing.

Maybe advanced gene manipulation technology isn't even a prerequisite; we could put enough people in space and let evolution do it's job.

Re:Shields up (1)

sumdumass (711423) | about 9 years ago | (#13778738)

There has been some discussion on this already from the 50's. I asume creating a magnetic field is somewhat simulare to creating a charged( i guess charged is redundant) ion field. I have seen drawings of what it might look like but fail to find references to them at the moment. The references i have seen were based on the moon but apear as they should be capable of working on a ship or space station.

Here [space.com] is a site explaining somethign simular to what i have read. Maybe i'm think of two different things. Maybe i'm confusing somethign form a scifi movie too?

Re:Shields up (0)

Anonymous Coward | about 9 years ago | (#13778781)

Why not reconfigure the main deflector array to emit a tachyon [ulse.

Or you could pokarise the hull plating.

The fantastic four (1)

UltimaL337Star (641853) | about 9 years ago | (#13778182)

let's not forget what it did for jean grey...

Re:The fantastic four (3, Informative)

grogdamighty (884570) | about 9 years ago | (#13778196)

Jean Gray was one of the X-Men, not the Fantastic Four...

Re:The fantastic four (2, Funny)

Anonymous Coward | about 9 years ago | (#13778235)

buuuuuuuuurn

(get it, it's a pun)

Re:The fantastic four (1)

UltimaL337Star (641853) | about 9 years ago | (#13779492)

I never said it she did, but to be fair, they are in the same universe... or were. Or are in a previous timeline...

that's about once every 11 years... (2, Funny)

HarveyTheWonderBug (711765) | about 9 years ago | (#13778190)

Not very pratical for commuting ...

Re:that's about once every 11 years... (1)

ZachPruckowski (918562) | about 9 years ago | (#13778710)

Yeah, and if it was this year, that means 2027. But we would have to come back in the normal conditions anyways, so it isn't really worth it, unless we want to have an 11 year mission. And I don't know many people who would volunteer for 11 years of isolation millions of miles from home.

Re:that's about once every 11 years... (1)

Lucractius (649116) | about 9 years ago | (#13779894)

mabey they could use hermits... promising them the ultimate in peace and alone time

Magnetize the hull? (3, Insightful)

aussie_a (778472) | about 9 years ago | (#13778193)

If I'm understanding this right, the magnetic properties of the solar flare cause the decrease in CME's? If so, couldn't ships magnetize their hull to shield the people inside? It obviously won't stop all the CME's, but it will decrease it.

Might turn out Enterprise's "ionize the hull" isn't as much sci-fi nonesense as it first sounds.

Re:Magnetize the hull? (1)

game kid (805301) | about 9 years ago | (#13778228)

I think it's more like CMEs and flares (both somewhat good) protecting the guys at the ISS from cosmic rays (immensely bad). Cosmic rays, not CMEs, seem to be the problem, and CMEs sweep them away as they pass Earth (think of a flyswatter through a swarm-the flies are swept away, but not totally or permanently).

So I think, anyway. All this flare and CME talk flared up my brainand almost made my head a splode.

Re:Magnetize the hull? (1)

redheaded_stepchild (629363) | about 9 years ago | (#13778238)

I had a very similar thought, when I read this. I couldn't find much info about effectiveness of blocking CMEs, but at least this [inchem.org] said it shouldn't cause severe harm to humans. Actually, shouldn't this kind of thing have been used previously, or is there some other reason we haven't tried magnetic sheilding?

Re:Magnetize the hull? (1)

sik0fewl (561285) | about 9 years ago | (#13778378)

What if we get stuck to a nearby asteroid with high metal concentrations? I guess the key is to latch onto one that's going the same place you are...

Re:Magnetize the hull? (1)

mordors9 (665662) | about 9 years ago | (#13778430)

Next thing you know, they will discover anti-matter or photons or something really crazy like that.

Re:Magnetize the hull? (1)

aussie_a (778472) | about 9 years ago | (#13778469)

Next thing you know, they will discover anti-matter or photons or something really crazy like that.

Well sorry for not realizing this beforehand. Sheeesh.

Re:Magnetize the hull? (0)

Anonymous Coward | about 9 years ago | (#13779398)

Next thing you know, they will discover anti-matter or photons or something really crazy like that.

Not to be too literal here, but...

antimatter: http://en.wikipedia.org/wiki/Antimatter/ [wikipedia.org]
photons: http://en.wikipedia.org/wiki/Photons [wikipedia.org]

And, just for kicks...

photon torpedoes: http://en.wikipedia.org/wiki/Photon_torpedoes [wikipedia.org]

Enjoy.

when to have space missions (5, Funny)

ScottSCY (798415) | about 9 years ago | (#13778199)

"So, I guess it would be safer to plan a manned Mars mission to coincide with peak sunspot activity?"
No, the real answer is to have space missions start on Sun-days. har har har har.

Re:when to have space missions (4, Funny)

aussie_a (778472) | about 9 years ago | (#13778218)

No, the real answer is to have space missions start on Sun-days. har har har har.

In space no-one can hear your terrible puns.

Re:when to have space missions (1)

Anonymous Coward | about 9 years ago | (#13778646)

> In space no-one can hear your terrible puns.

Awww! And no one even made bad political puns about the "Forbush decrease" yet!

Re:when to have space missions (1)

Yehooti (816574) | about 9 years ago | (#13778230)

Dang, but this is good news. I had an uncomfortable feeling that heavy solar activity might be a show stopper for a manned Mars mission. During September's storms I feared the space station's crew were getting hammered.

Mars trip during solar storm (4, Insightful)

Bananatree3 (872975) | about 9 years ago | (#13778229)

"So, I guess it would be safer to plan a manned Mars mission to coincide with peak sunspot activity?"

Well, that could be a logical conclusion from the article. BUT, what also occurs during major sunspot activity?. Mondo solar flares! Yes, they may help suppress the Cosmic Radiation. But, I sure wouldn't want to be stuck somewheres in the vast space between Mars and Earth with one of these monsters heading for me. The spaceship would be hit like a rowboat in a hurricane, in terms of solar radiation.

Re:Mars trip during solar storm (4, Informative)

saskboy (600063) | about 9 years ago | (#13778334)

You're correct. The submitter didn't realize that cosmic radiation and solar radiation are not the same thing, since solar radiation is the stuff that comes from our sun, and cosmic radiation comes from sources outside of our solar system like other stars, black holes, pulsars, nova, and other big bad radiation machines out there.

There may be a decrease in radiation coming from elsewhere, but the ship would still be hammered by high speed Coronal Mass Ejection particles. Radiation sheilding is essential; Bring your polyethylene, in other words.

Re:Mars trip during solar storm (2, Interesting)

necro81 (917438) | about 9 years ago | (#13778549)

An excellent point, and one that probably will mean that it is, in fact, safer to try and avoid spaceflight during high solar activity (when possible). On the other hand, the danger is only there if the CME is directed in your general vicinity. Sure, the Earth gets hit with a solar flare (or its remnants, actually) from time to time, but it does not get hit with every solar flare the Sun produces.

Re:Mars trip during solar storm (2, Insightful)

imikem (767509) | about 9 years ago | (#13778641)

Coronal mass ejections send huge numbers of high energy protons into space. These are far more easily shielded by standard spacecraft construction techniques than cosmic/gamma rays. No contest between which scenario is more dangerous. The main danger during CMEs is to EVA (spacewalks), since the pressure suits are not easily shielded to a sufficient degree.

Danger Level (0, Redundant)

Excilus (913319) | about 9 years ago | (#13778236)

Just how dangerous are these cosmic rays anyway?

Re:Danger Level (1)

DigiShaman (671371) | about 9 years ago | (#13778356)

Nothing special...other then having your nutsack shrivel up and fall off in a few months.

Re:Danger Level (4, Informative)

Biff Stu (654099) | about 9 years ago | (#13778370)

I once had a chat with a NASA biomedical researcher who told me that astronauts in space occasionally see flashes of light. These flashes coincide with cosmic rays destroying cones and/or rods in their retina. Not a pleasant thought if you ask me.

Of course, these same cosmic rays will also destroy cells in the brain and fragment DNA, potentially generating damage which could either lead to cancer or lead to genetic problems which could be passed on to future generations.

Although I can't quantify the risk associated with the latter phenomena, knowing that every time I see a little flash I have suffered a small but permanent loss of vision would make space travel less appealing.

Re:Danger Level (1, Funny)

Anonymous Coward | about 9 years ago | (#13778428)

Of course, these same cosmic rays will also destroy cells in the brain and fragment DNA, potentially generating damage which could either lead to cancer or lead to genetic problems which could be passed on to future generations.

Duude, you're full of crap! My cellphone does the same thing, and they say it's perfectly safe. Can you hear me now? Can you hear me meow? What?

Re:Danger Level (1)

Excilus (913319) | about 9 years ago | (#13779001)

I'm not one hundred percent sure that could be right... If you see a flash it means an action potential in a rod of cone fired. It's very hard to believe that a cosmic ray is going to, say, cause a potential difference sufficent to fire an action potential: you'd need some kind of interaction with the cells themselves opening a sodium channel or something. I guess when cells die they tend to fire off a bit, but to actually SEE a flash you'd need to have many of these things going on simultaneously. In general, ionizing radiation is bad. But just how much more damaging are cosmic rays?

Re:Danger Level (1)

mefein (664330) | about 9 years ago | (#13779066)

I doubt that all the cosmic-ray light flashes in the eye are destroying rods or cones. Cosmic-rays (which are relativistic charged particles) produce a flash of blue light when they move faster than the spped of light in a medium. This is known as Cherenkov light. This would produce an observable flash of light which would not be damaging to the eye. On the other hand, sometimes the cosmic-ray might interact directly in cells in the eye which may cause damage. I have heard that in the early days, some particle/nuclear physicists used the light flashes in their eyes to align their particle beams.

Shields up!! (1)

$RANDOMLUSER (804576) | about 9 years ago | (#13778239)

So how about I use the cheap solar energy to run a Van de Graff generator and put about 167TeV into a metal shell around my ship?

Re:Shields up!! (0)

Anonymous Coward | about 9 years ago | (#13778305)

A Van de Graaff won't work too well in a vacuum, eh?

Re:Shields up!! (1)

$RANDOMLUSER (804576) | about 9 years ago | (#13778339)

Why? Electrons won't jump across a vacuum?

Re:Shields up!! (0)

Anonymous Coward | about 9 years ago | (#13778709)

They might, if they're captive in a magnetic belt. Can we have our portable Van Allen?

Re:Shields up!! (1)

rob_squared (821479) | about 9 years ago | (#13779585)

Sure they do, it takes more effort, because interplanetary space isn't true vacuum. It's a harder vacuum than we can produce, but there's still 10^4 atoms per cubic meter.

ISS is inside the van allens/earh's magnetic field (4, Insightful)

Pottsynz (756353) | about 9 years ago | (#13778240)

Hence its hardly a perfect testbed for radiation effects regarding long-term space flights. You have to wonder if the factored in the change solar activity makes to the earth's magnetic field when putting this all together.

It is... (0)

Anonymous Coward | about 9 years ago | (#13778254)

tikonauts, you insensitive clod!

No protection from death rays! (3, Funny)

uncoveror (570620) | about 9 years ago | (#13778255)

Solar flares may protect astronouts from cosmic rays, but will provide no defense against death rays [uncoveror.com] or destructo-rays! [uncoveror.com]

Re:No protection from death rays! (0)

Anonymous Coward | about 9 years ago | (#13778321)

Solar flares may protect astronouts from cosmic rays, but will provide no defense against death rays or destructo-rays!

That's why we should "set us the bomb"!

Re:No protection from death rays! (1)

sharkey (16670) | about 9 years ago | (#13779284)

What about sex rays? [imdb.com]

Asgard Shielding Technology (1)

cyko500 (315074) | about 9 years ago | (#13778261)

The SGC really needs to start trickling that stuff down to NASA...

Re:Asgard Shielding Technology (1)

cyko500 (315074) | about 9 years ago | (#13778367)

Well, it looks like we will actually be getting some asgard shielding [asgard.ethz.ch] on the ISS afterall! Woohoo!

trip to the sun... (1)

yddod (778690) | about 9 years ago | (#13778272)

why not plan a trip to the sun, she be nice and safe there....

NASA source (4, Informative)

saskboy (600063) | about 9 years ago | (#13778306)

NASA Science News for October 7, 2005

Another source:

Strange, but true: Solar flares can be good for astronauts. [nasa.gov]

Re:NASA source (2, Interesting)

Jeff DeMaagd (2015) | about 9 years ago | (#13778320)

True, sadly, Slashdot is reposting yubanet's repost of NASA's story of last week. Even worse, Slashdot will repost this story within 24 hours.

Re:NASA source (1)

rob_squared (821479) | about 9 years ago | (#13779596)

If you want to continuously refresh hundreds of sites to get your news quicker, then you'll get your news quicker. Or hey, you could watch the news or listen to the radio. Most of us, yourself included, come here for the conversation.

aha! (1)

icepick72 (834363) | about 9 years ago | (#13778346)

I knew there must have been a flaw in the Fantistic 4 movie. This is it!

Toaster Pastries (0)

Anonymous Coward | about 9 years ago | (#13778366)

Thats great and all, but how it it going to effect me? I don't work for Nasa or any aerospace company for that matter.

Maybe they can tell me when there will be a solar flare so I can conduct my toaster pastry experiments. I feel that these will revolutionize the way everyone eats breakfast!

Nothing is more... (1)

HeroSandwich (920245) | about 9 years ago | (#13778369)

Nothing is more Airwolf than Airwolf! Cheers!

No, schedule the trip for studio time... (0)

Anonymous Coward | about 9 years ago | (#13778373)

So when NASA fakes the Mars landings, they get a cheaper rate....

Except that... (2, Interesting)

Anonymous Coward | about 9 years ago | (#13778401)

The reason for this decrease in galactic cosmic rays is that the solar flares and coronal mass ejections themselves emit relativistic electrons and solar cosmic rays (mostly protons) which are responsible for pushing the galactic particles back. The number of solar energetic particles emitted during flares is much larger than the galactic source. In addition to the energetic particles, the sun also emits copious amount of hard and soft X-rays during solar flares.

I don't think that it matters much to an astronaut whether the ionizing radiation is galactic or solar in origin. As for solar flares improving the radiation environment inside the space station, I find that statement very curious. With experts such as this, maybe that's why they announced the closing of the Space Environment Effects division at NASA last week.

Re:Except that... (1)

oolleq (742995) | about 9 years ago | (#13778731)

The ISS is in Low Earth Orbit, deep inside the Earth's magnetic field. Solar flares dump huge amounts of energy into the Earth's magnetic field. The more engergy, the further south the Aurora Borealis appears, as the magnetic field pulls particles from the solar wind to larger circles further away from the poles. The temporary increase in the strength of the Earth's magnetic field protects astronauts in the ISS; astronauts on their way to Mars, unprotected by the Earth's magnetic field, would have both the usual cosmic background radiation in addition to the increased solar radiation.

Our planet's magnetic field is decreasing in strength. It flips poles every half million years or so, and we're overdue for a flipping. The last flip came about 700 million years ago, when a dinosaur killer sized meteor struck Antarctica. That one came straight down into ice a few klicks deep, instead of the shallow impact into a sulfur deposit like Chixulub 65 million years ago.

There's evidence (http://www.nuclearplanet.com/ [nuclearplanet.com] ) that Earth's magnetic field may be caused by the fissioning of a bunch of uranium at the Earth's core, and that the helium 3 emissions from volcanos suggest that we're within a century to a million years of running out of fissionables, which would leave Earth without a magnetic field, like Mars or Venus. Geologists aren't warm to the theory, but the US Dept. of Energy is paying attention...

Re:Except that... (2, Interesting)

Anonymous Coward | about 9 years ago | (#13779092)

"Solar flares dump huge amounts of energy into the Earth's magnetic field. The more engergy, the further south the Aurora Borealis appears, as the magnetic field pulls particles from the solar wind to larger circles further away from the poles."

Not exactly. What happens is that with the increased solar wind pressure the magnetosphere becomes distorted, the auroral oval expands equatorwards, and electric currents start flowing. "Magnetic reconnection" events in the magnetotail energize magnetospheric (not solar wind) particles and inject them into the auroral zones resulting in the visible aurora.

Whether or not astronauts are exposed to auroral zone radiation depends on the location of the auroral oval (it expands equatorwards during high geomagnetic activity induced by solar disturbances) and the inclination of the spacecraft orbit. I have satellite (X-ray) images of the auroral oval as far south as Washington DC during one large storm.

For a view of the current "space weather" conditions, see:

http://sohowww.nascom.nasa.gov/spaceweather/ [nasa.gov]

The ACE satellite sits upstream of earth in the solar wind and monitors the solar wind ram pressure and the interplanetary magnetic field Bz component. The NOAA/POES satellite shows images of the current auroral oval (now in its quiet phase).

An excellent article on galactic and solar cosmic rays is here:

http://www.research.ibm.com/journal/rd/421/ziegler .html [ibm.com]

If you're wondering why companies like IBM are interested in this, it's because cosmic rays penetrate semiconductor chips and cause "single event upsets" in computers. Or they can knock out an entire satellite. Computer chips need to be "hardened" against radiation before they are space-qualified.

In case you're wondering, I have a PhD in space science lying around here somewhere .....

Can we get that down here??? (0, Offtopic)

SwedeGeek (545209) | about 9 years ago | (#13778425)

I don't care much about a 30% "Forbush descrease" in outer space... but I'd sure like to see if solar flares can create a 100% "for Bush decrease" in the U.S.!

Re:Can we get that down here??? (1)

SwedeGeek (545209) | about 9 years ago | (#13778510)

Offtopic?? What? Can't anyone on /. take a joke anymore??? Mods, please help! (see above)

Re:Can we get that down here??? (0)

Anonymous Coward | about 9 years ago | (#13778535)

Maybe people are just sick of idiotic Bush bashing? Be thankful you weren't modded 'Troll'.

Re:Can we get that down here??? (1)

SwedeGeek (545209) | about 9 years ago | (#13778648)

Well, I certainly won't deny it was Bush bashing, but "idiotic" is definitely a bit harsh. They put the phrase in quotes right in the post, for Pete's sake. That's not idiotic, that's taking advantage of a perfect lay-up.

Talk about being kept down by the man. Geesh!

A ForBush Decrease? (1)

mexter2005 (854056) | about 9 years ago | (#13778471)

Isn't this the same phenomena that cost Gore the election in 2000? - ME -

Forbush decrease? (1)

joemawlma (897746) | about 9 years ago | (#13778474)

Yeah. It's at like 40-something percent approval rating still.

The % of people who are forbush needs to drop to 0% already!

Re:Forbush decrease? (1)

joemawlma (897746) | about 9 years ago | (#13778507)

DAMN IT! Everyone always sneeks the same comment in RIGHT before me!

Re:Forbush decrease? (2, Insightful)

SwedeGeek (545209) | about 9 years ago | (#13778673)

<whine>
Well, at least your karma didn't spanked for it like mine did... :(
</whine>

Re:Forbush decrease? (0)

Anonymous Coward | about 9 years ago | (#13778732)

You can never bash Bush too much anyway, especially if you are black and/or poor.

How about that economy and reasonable gas prices as an oilman holds an oil country hostage and gets all the more rich along with his other cronies off these reasonable and well explained gas prices which just cannot be helped but make oil men richer.

Look at the good side anyway, when they bring back the draft it will only be all the easier to kick that kid out of your house and somewhere else even if it is to die for nothing in a desert.

Oh yeah, solar radiation made me post this.

I always knew I was special (1)

Solr_Flare (844465) | about 9 years ago | (#13778493)

It's a tough job shielding those astronaughts between my attempts to destroy the worlds electronics.

Great, but... bone loss still a problem (2, Informative)

justsomecomputerguy (545196) | about 9 years ago | (#13778573)

Not saying the bone loss problem can't be solved, but ever since hearing about the bone loss problem I've felt that radiation would be easier to solve than bone loss.

A simplistic source, (http://www.factmonster.com/ipka/A0778174.html [factmonster.com] ) has this easy to digest quote
"... And because the gravity on Mars is only 38% of Earth's, ways to counteract any damaging effects of the weak gravity on their bodies, such as progressive bone loss and muscle atrophy, will have to be found. Currently, there is no fully effective treatment for microgravity-induced bone loss, and counter measures against bone loss are a top space science priority."

For deeper reading try:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd= Retrieve&db=PubMed&list_uids=15852539&dopt=Citatio n [nih.gov]

The Ultimate Solution!!!! Maybe. (1)

eonlabs (921625) | about 9 years ago | (#13778813)

Actually, what happens if all three are used in tandem?

Use magnetic fields to shield the ship from plasma by funneling it into a reactor rather than repelling it.

The solar flare blocks radiation, fuels the ship, and could potentially provide enough fuel to solve the bone mass issue.

The bone mass issue is caused by being in zero G, but if you're constantly under acceleration, you don't suffer from being in zero G. You also go places much faster than if you allow yourself to travel in free fall.

Accelerate the first half of the trip, turn around and accelerate the other direction the second half, and you have launch, the day you turn around, and landing in zero G.

Not a horrible solution, don't you think?

Larry Niven had some great ideas when it came to magnets and hydrogen reactors.
Even capturing plasma flying out of a solar flare will accelerate you because you absorb energy from the plasma in capturing it!

Re:Great, but... bone loss still a problem (1)

Itanshi (861931) | about 9 years ago | (#13778821)

I say we breed martians on our martian colony and let evolution take its course, really. Hmm, we'd have green midgets, right? Well maybe not green.

Not an obvious extrapolation... (1)

Goonie (8651) | about 9 years ago | (#13779101)

From the abstract (the full paper doesn't seem to be online) he's assuming the bone loss on Mars will be the same as it is in zero-G. There is, however, AFAIK currently zero experimental data to support that assumption.
There are any number of possible models for bone loss on partial gravity. It might be that there's no accelerated bone loss at all once gravity is above some minimum value. It might be a linear relationship. Or something more complex again.

The MarsGravity biosatellite [marsgravity.org] will hopefully provide some answers on this point, assuming it's ever launched. But at the moment you're taking a very glass-half-empty point of view.

MarsGravity Biosatellite (1)

R3d M3rcury (871886) | about 9 years ago | (#13779890)

Actually, speaking of the MarsGravity biosatellite, I have an odd question.

Why don't they just develop the little spinny thing to hold and feed the mice and send it up on the next Progress Drone to the ISS? Why are they developing their own satellite with it's own life-support system when we have a perfectly good space station that has a life-support system, as well as a couple of guys to monitor the experiment and the mice and potentially fix anything that goes wrong.

And rather than developing the heat shield, parachute, and airbags to bring the mice home, they could just bring the mice back on the next ISS "shift change" on a Soyuz capsule.

I mean, why involve all the rocket science? These problems have been solved. I'm sure they can build a little spinny habitrail type of thing for a fraction of the cost of building a whole satellite with a return system.

Too fucking bad we think space is/should be safe (0)

Anonymous Coward | about 9 years ago | (#13778616)

Because this is all moot.

As long as people are too stupid to realize that ANY space travel is going to be a risk this is all for not. When as a country we can again accept that there will be a risk involved in any exploration and especially that of space, then we can get manned vehicles in orbit again and truly start moving towards planetary travel. Now here there is a big whoop over one of the more forgotten dangers in space and people still cry over some foam that has fallen off shuttles since their rollout in the 80s. Once we grow up again and can accept that we will never get rid of 100% of the ever present dangers of space travel/flight, we can move forward again and start to get more research and data on this topic.

Until then, keep your stone tipped spear and furs handy as they match the mindset of our species the most accurately.

For Bush (0, Redundant)

dogbreathcanada (911482) | about 9 years ago | (#13778924)

"Forbush decrease" If only we'd had that during the 2004 elections.

A solar physicist speaks... (4, Informative)

Dr. Zowie (109983) | about 9 years ago | (#13778955)

The problem with going at solar minimum is that more galactic cosmic rays make it inward to the inner solar system, increasing radiation dose. The problem with going at solar maximum is occasional sudden death from energetic proton streams. Solar flares cause three main hazards: gamma rays from the flare itself (a problem but not a lethal one for most events); energetic protons that are accelerated by the flare and any post-flare coronal mass ejection; and bulk clouds of material that are thrown off by the Sun and that entrain magnetic fields.

The energetic protons are a real problem for man and machine. They arrive minutes to hours after the flare itself is seen. They have a high "quality factor", meaning they do a lot more biological damage than an equivalent ionizing dose of X-rays or gamma rays; and they tend to embed themselves in insulators, developing a humongous static charge that screws with electronic circuits and can burn out components. The clouds are more of a problem for planet-sized bodies (like the Earth) than for astronauts, but they do have some potential health consequences. They travel at "only" 1-4 million miles per hour, arriving at Earth about 1-4 days after the solar event.

Over the last three years we've had six or seven large flares that could have caused radiation sickness or death for Apollo astronauts (or Mars-bound astronauts with similar amounts of shielding to a mere Apollo capsule). That's enough that you'd have to expect at least one such event during a Hohmann transfer orbit to Mars, if you travelled at this phase of the solar cycle (declining).

The space station is largely shielded from the energetic protons, because it stays in low Earth orbit, underneath the Van Allen radiation belts -- Earth's magnetosphere diverts the protons away from the station. But the high energy galactic cosmic rays have no trouble passing through and hitting the station. So station astronauts are (probably somewhat) safer during solar maximum, but interplanetary astronauts are (probably) safer during solar minimum. Either way the radiation dose is a problem that has to be designed around.

Incidentally, the largest effect of solar activity on the space station is orbital decay! During solar maximum, the increased far-ultraviolet brightness of the Sun heats the outer layers of the atmosphere (the "thermosphere"), making them expand significantly -- that increases orbital drag a LOT. It's one reason (the other being delays in the Shuttle program) that Skylab re-entered the atmosphere before the Shuttle came on-line to provide additional boost. Skylab was launched during solar minimum in the mid 1970s, and the orbital decay projections were based on solar minimum conditions. It re-entered several years earlier than initially expected, because the atmosphere (and hence orbital drag) got larger in the solar maximum period of the late 1970s. The space station has similar orbital-decay issues; if you Google for the altitude-versus-time plots, you'll see that at its chosen altitude, the ISS needs to be boosted every six months or so, or it will spiral in and re-enter the atmosphere.

"After" (1)

EternityInterface (898741) | about 9 years ago | (#13779343)

It's called a "Forbush decrease," after American physicist Scott E. Forbush

You know in Sweden everyone's called Johansson, so it would really be a bummer if too many Swedes were scientists, I mean, it might cause an epidemic making people actually name things based on what they fucking are.

Solar Flare or Cosmic Ray (1)

layer3switch (783864) | about 9 years ago | (#13779388)

Either way, seems like a horrible way to "DIE". It's like getting lethal injection but 1 million watt electricity rid of 30% of the lethal chemical in your body.

hmm.. did I just invented a new way to execute people?

Fantastic! (1)

TheStonepedo (885845) | about 9 years ago | (#13779414)

Without properly tuned shields the astronauts may turn to stone, or become invisible, or get really stretchy, or turn into fireballs.

Safer? No. (1)

SEE (7681) | about 9 years ago | (#13779682)

So, I guess it would be safer to plan a manned Mars mission to coincide with peak sunspot activity?

Peak sunspot activity means peak coronal mass ejection (solar flare) activity. A really large solar flare can inflict thousands of rems in a short period of time, while you'd be reducing cosmic ray exposure by tenths of a rem per week. Even smaller flares will influct tens or hundreds, and at any reasonable interplanetary speed, you'll get hit by several during a sunspot peak.

If you've got the Van Allen belts between you and the Sun, and are spending half your time shielded from flares by the mass of a planet anyway, yeah, you're better off at the solar maximum, because you're shielded enough from flares that the cosmic ray deflection rsults in a net reduction. But if you're going to some other body in the Solar System, going at the maximum is suicidal.
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