[HN Gopher] Swarm satellites probe weakening of Earth's magnetic...
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Swarm satellites probe weakening of Earth's magnetic field
Author : throw0101a
Score : 206 points
Date : 2020-05-28 10:40 UTC (12 hours ago)
(HTM) web link (www.esa.int)
(TXT) w3m dump (www.esa.int)
| trail-system wrote:
| "Over the last 200 years, the magnetic field has lost around 9%
| of its strength on a global average. A large region of reduced
| magnetic intensity has developed between Africa and South America
| and is known as the South Atlantic Anomaly."
|
| The South Atlantic Anomaly is interesting. In past years
| satellites are being made to shutdown while passing the regions
| to avoid damage from the lack of protection from harmful
| particles.
| tboerstad wrote:
| Fascinating information, today I learned. Out of curiosity, do
| you work in the industry?
| trail-system wrote:
| I'm not in the industry. Just a fan of anomalies.
| cuSetanta wrote:
| Not the original commenter but I am in the industry, and its
| true, many satellites shut down during this region over the
| South Atlantic.
|
| For that reason, it is not a popular orbit unless there is a
| larger driver behind the selection. For example the ISS goes
| right through it in order to be above Russia for a reasonable
| portion of its orbit. I believe Astronauts have reported
| increases in optical flashes during this part of the orbit as
| more energetic particles pass through their eyes.
| [deleted]
| JshWright wrote:
| I'm not the commenter you're repling to, but personally I
| think I originally learned about the SAA from a Scott Manley
| video.
| iso947 wrote:
| I suspect this one, explaining the various parts of mission
| control
|
| https://youtu.be/6zFAme3SQAo
| hawski wrote:
| Link for the lazy:
| https://en.wikipedia.org/wiki/South_Atlantic_Anomaly
|
| It seems to cover almost whole South America.
| koheripbal wrote:
| It's interesting - I wonder if there are more transient and
| localized magnetic anomalies?
| mike_ivanov wrote:
| "Sorry to disappoint the "we're all going to die" crowd, but the
| South Atlantic Anomaly has been developing at least since 1840,
| and appears to be an effect of long-term, mysterious flows in
| Earth's outer core."
|
| https://twitter.com/coreyspowell/status/1264999851655335936
| paucanosa2 wrote:
| Good post
| gadjo95 wrote:
| Is it dangerous for human ? I'm thinking like the ozone hole we
| used to have in South America in the past.
| edna314 wrote:
| Should be possible to estimate how long it would take to
| hypothetically spread over the whole globe (this probably won't
| happen). Any idea what time scales we are talking about here? My
| best guess based on the animation would be ~50 years rather than
| hundreds of years, but would be nice to have a solid estimate
| rather than guessing.
| politelemon wrote:
| > It has been speculated whether the current weakening of the
| field is a sign that Earth is heading for an eminent pole
| reversal
|
| It's not often mentioned but these pole reversals aren't
| sudden/instantaneous across the planet. They can take a few
| thousand years to complete.
|
| See: https://en.wikipedia.org/wiki/Geomagnetic_reversal
|
| The most interesting part to me, from the Wikipedia page is:
|
| > The magnetic field will not vanish completely, but many poles
| might form chaotically in different places during reversal, until
| it stabilizes again.
| trail-system wrote:
| "It's not often mentioned but these pole reversals aren't
| sudden/instantaneous across the planet. They can take a few
| thousand years to complete."
|
| I've actually seen that fact mentioned quite often within
| articles and news regarding pole flips as a reassurance to the
| reader.
|
| "The magnetic field will not vanish completely, but many poles
| might form chaotically in different places during reversal,
| until it stabilizes again."
|
| The field would not vanish completely but most of the world
| would lack protection from massively dangerous cosmic
| radiations and solar particles.
| AnotherGoodName wrote:
| If the magnetic field completely disappeared tomorrow the top
| layers of the atmosphere would start to be ionized and
| stripped away. There'd also be a slow change in the
| composition of the atmosphere due to neutron bombardment.
|
| The process would only take a mere million years or so!
|
| In the meantime the Earths atmosphere alone also blocks
| cosmic radiation to the extent that there's no immediate harm
| to life.
| Supernaut wrote:
| Is "eminent" a technical term used in the discussion of
| magnetic poles? Or did the author actually mean "imminent"?
| jfk13 wrote:
| Imminent, I think.
| BurningFrog wrote:
| It's seriously discussed to give Mars a "protective" magnetic
| field like Earth has, by putting a powerful magnet in the L1
| Lagrange Point.
|
| We could get something like that for Earth if our field is out
| for maintenance for a while.
|
| https://www.extremetech.com/extreme/245369-nasa-proposes-bui...
| [deleted]
| alex_duf wrote:
| Am I correct this potentially weaken our shielding against
| charged particles coming from the Sun?
|
| And if so, is it opening the possibility of having northern
| lights in the middle of the Atlantic?
| trianglesphere wrote:
| Yes, but it's very localized. The magnetic field of earth is
| typically modeled as a dipole where the magnetic field strength
| is the same as you go around the equator at the same altitude.
|
| Maybe with northern lights over equator, I'd have to think
| about it more, but it's odd to think of an aurora where the
| magnetic field lines are parallel with the ground rather than
| normal to the ground (particles are much more mobile along
| field lines rather than across field lines in plasmas).
| trail-system wrote:
| From NOAA (https://www.swpc.noaa.gov/phenomena/aurora)
|
| When space weather activity increases and more frequent and
| larger storms and substorms occur, the aurora extends
| equatorward. During large events, the aurora can be observed as
| far south as the US, Europe, and Asia. During very large
| events, the aurora can be observed even farther from the poles.
| simias wrote:
| That's a very weird and not very precise way to word this. Of
| course I would expect auroras to be regularly visible in the
| far northern parts of the USA and Europe:
|
| https://en.wikipedia.org/wiki/File:Aurora_Kp_Map_North_Ameri.
| ..
|
| https://en.wikipedia.org/wiki/File:Aurora_Kp_Map_Eurasia.gif
|
| Now if you start seeing Auroras in Lisbon or Miami please let
| me know!
| iso947 wrote:
| Auroras were seen in Baltimore and Perth (Australia) during
| the Carrington event in 1859, around Lisbon's latitude
| (both north and south)
| contravariant wrote:
| Lisbon would be worrying but Miami would be catastrophic.
|
| Portugal might be more northern than you think. It's only
| just south of Toronto.
| blickentwapft wrote:
| >> At surface level, the South Atlantic Anomaly presents no cause
| for alarm.
|
| I still feel an irrational sense of alarm.
| koonsolo wrote:
| Yes, especially during these corona times... "We are not
| prepared!!!" ;).
| outworlder wrote:
| Wait until the anomaly is combined with a ... Coronal mass
| ejection!
|
| :)
| acd wrote:
| By looking at the video it looks like an anomaly in the Amazonas.
| What is causing this? Deforestation?
|
| If so we need to change economic system to one based on nature.
| So that eco systems have an economic value. Ie a tree in Amazonas
| has a value to earth and its inhabitants since it provides
| oxygen. In current market economic system common resources are
| not priced fully. It may be profitable to chop down tree and sell
| the wood. Use previous Amazonas land for example to create more
| farmland to breed cows.
| ashtonkem wrote:
| If deforestation caused magnetic anomalies, we'd have noticed
| it a long time ago in several locations, including America.
|
| Magnetism is driven by Earth's core.
| defnotashton2 wrote:
| Political solution, inventing a problem
| mportela wrote:
| The center is actually more to the south. It seems to be over
| Paraguay and southern Brazil, thousands of kilometers away from
| the Amazon rainforest.
|
| "What is causing this?"
|
| Well... that's exactly the point, right? No one knows what's
| causing it.
| kylek wrote:
| NOAA has a map showing historical data of the pole movements -
|
| https://maps.ngdc.noaa.gov/viewers/historical_declination/
| shirak_untel wrote:
| Maybe this means it's time for the magnetic pole to flip? Damn,
| I'd like to see this in my lifetime
| mirekrusin wrote:
| Does anybody know if flipping, earth being without
| strong/stable magnetic field for decades/centuries could have
| been cause of dinosaur extinction?
| yoz-y wrote:
| I know almost nothing about this but I'd say this is
| unlikely. The dinosaur era spanned millions of years and the
| poles flip several times per million years. So they survived
| through dozens of flips.
| pp19dd wrote:
| There was a 2013 paper titled "Mass Extinction and the
| Structure of the Milky Way" that you might find interesting:
| https://arxiv.org/abs/1309.4838 - I don't know if there have
| been any significant follow ups since it published.
|
| Basically our galaxy is a spiral galaxy with four arms, and
| it's rotating. The center moves slower than the outside, and
| our sun's orbit is near the inner rim of the Orion arm. We
| orbit the galaxy roughly every 240 million years and in that
| time we cross the dense galactic arms every so often (arms
| aren't symmetrical).
|
| The paper: "A correlation was found between the times at
| which the Sun crosses the spiral arms and six known mass
| extinction events."
| throwanem wrote:
| Yeah, and they only had to design an entirely novel and
| significantly asymmetrical model for the shape of the Milky
| Way Galaxy to do it.
| bouvin wrote:
| According to Wikipedia [0], there have been 183 magnetic
| reversals the past 83 million years (and many more throughout
| the history of the Earth, including the reign of the
| dinosaurs). The weakening of the Earth's magnetic shielding
| is no laughing matter, but the impact of the Chicxulub
| asteroid was certainly far greater.
|
| [0] https://en.wikipedia.org/wiki/Geomagnetic_reversal
| blaser-waffle wrote:
| You'd like to see that in your lifetime?
|
| It's gonna be a bad time, man.
| zmkzrk wrote:
| I'd recommmend Sunfall by British physicist Jim Al-Khalili as an
| entertaining fictional account of the catastrophic effects of an
| weakening in the Earth's magnetic field, followed by attempts to
| remotely restart flow activity in the core.
| jl6 wrote:
| Since Earth's magnetic field derives from the convection currents
| of magma in the outer core, and since moving magma also drives
| tectonic activity... is there any potential relationship between
| this anomaly and earthquakes/volcanos?
| snowwrestler wrote:
| The magnetic field is generated in the outer core, while
| surface vulcanism and earthquakes are driven by the upper
| mantle. These areas are about 2,000 miles different in depth.
| There's obviously some kind of relationship because it's all
| one planet, but nothing direct enough to care about in this
| situation.
| ibigb wrote:
| Interestingly the first person to talk about pole reversals was
| the American holistic healer Edgar Cayce. On the 11th day of
| August, 1936: Q What great change or the beginning of what
| change, if any, is to take place in the earth in the year 2,000
| to 2,001 A.D.? (A) When there is a shifting of the poles. Or a
| new cycle begins. Ref [826-8]
|
| Geologist of the time did not believe a word of it. However,
| during WW2 the detecting instrumentation for submarine warfare
| detected on the sea floor alternating bands of magnetic
| polarization, which is now evidence for the reversal of the
| magnetic poles. Humans do have non-physical experiences, e.g.
| dreams, etc. but now most non-physical experience is discounted,
| ignored, except for thinking.
| koheripbal wrote:
| This is why claims without evidence are effectively
| meaningless.
|
| It's not enough to have a belief. At the very least, you need a
| logical derivation of your theory.
|
| If I threw out a prediction in this comment that just happened
| to become true in 100 years, should I get any credit for it?
| Should people think that I somehow had some special insight?
| No.
|
| Logic & evidence. Those are the only things of value when make
| claims or predictions.
| burkaman wrote:
| > the first person to talk about pole reversals was the
| American holistic healer Edgar Cayce. On the 11th day of
| August, 1936
|
| Geophysicist Motonori Matuyama talked about geomagnetic
| reversals in the 1920s:
| https://en.wikipedia.org/wiki/Motonori_Matuyama
|
| > When there is a shifting of the poles. Or a new cycle begins.
|
| He actually is not talking about magnetic poles. He clarifies
| further:
|
| "There will be shifting then of the poles - so that where there
| has been those of a frigid or the semi-tropical will become the
| more tropical, and moss and fern will grow. And these will
| begin in those periods in '58 to '98, when these will be
| proclaimed as the periods when His light will be seen again in
| the clouds. As to times, as to seasons, as to places, alone is
| it given to those who have named the name - and who bear the
| mark of those of His calling and His election in their bodies.
| To them it shall be given." - https://www.edgarcayce.org/about-
| us/blog/blog-posts/cayces-p...
|
| > Geologist of the time did not believe a word of it.
|
| I mean, did anybody ask them? Perhaps they would have been
| familiar with Professor Matuyama's work.
|
| Finally, how many other predictions did he make? Any chance
| people have cherry-picked a couple of his ideas that seem kind
| of close to right?
| itchyjunk wrote:
| Could this time of field weakening and events such as cambrian
| explosion[0] be related?
|
| Does any human activity impact Earth's magnetic field directly or
| is it irrelevant at this scale? Activity like mining metals out
| of the planet, large amounts of construction. Movement of metal
| in ways of air planes and vehicles.
|
| If molten magma is the source of our magnetic field and the earth
| slowly spews out lava over time, is it causing out magnetic field
| to weaken over time?
|
| This might be slightly offtopic but what do you make of the
| concept that magnetic fields and global warming might be
| associated? [1]
|
| [0] https://en.wikipedia.org/wiki/Cambrian_explosion
|
| [1]
| https://ui.adsabs.harvard.edu/abs/2006AGUFMGP51B..02F/abstra...
| hoorayimhelping wrote:
| I thought the Cambrian explosion was more closely related to
| the oxidization of the atmosphere by pond scum. Free oxygen
| becoming available in the atmosphere for organisms to use
| allowed the formation of collagen and chitin, both of which are
| necessary to form the large structures complex life needs, and
| also allowed for more efficient breathing, which allowed for
| larger and more complex life.
| btilly wrote:
| Interesting.
|
| The theory that I heard was that it was the end of "snowball
| earth" that drove it.
|
| But https://www.nature.com/news/what-sparked-the-cambrian-
| explos... suggests that your version is better supported by
| current research.
| lopmotr wrote:
| That word oxidization or oxidation is really misleading! It's
| not that the atmosphere was oxidized but the opposite - CO2
| was reduced to produce free oxygen molecules. I think it
| should be called "oxygenation" instead.
| SkyBelow wrote:
| The disparity in the magnitudes of energy involved should mean
| human activity has a negligible effect. When you consider how
| massive earth is, how massive the core is, and how much energy
| it takes for the core to have the angular momentum it currently
| does, what few things we are doing to the crust aren't relevant
| except in very localized areas that do not extend to the height
| of these satellites.
| Hendrikto wrote:
| > Activity like mining metals out of the planet, large amounts
| of construction. Movement of metal in ways of air planes and
| vehicles.
|
| That is ENTIRELY insignificant, and not even worth mentioning.
| The deepest hole humans have ever been able to create was about
| 12km deep. That is less than 0.18% of the earth's radius.
|
| Human activity is limited to the upper parts of earth's crust,
| which is itself only a fraction of earth. Magnetism happens
| WAAAAAY deeper.
| freeflight wrote:
| _> Human activity is limited to the upper parts of earth's
| crust, which is itself only a fraction of earth. Magnetism
| happens WAAAAAY deeper._
|
| But doesn't that assume that metal/mineral deposits closer to
| the surface, or at the surface, those that humanity has
| mostly exploited, do have no effect at all?
|
| What if surface deposits and those closer to it act as some
| kind of "coating" leading to slight changes in dynamics we
| still don't understand or might not even realize yet actually
| exist? When we are very much like ants: In the singular
| seemingly insignificant, a single ant would never be seen as
| capable as "harvesting" any bigger animal carcass. Yet the
| scale and endurance of these ants make it possible for them
| to slowly pick apart something that would normally consider
| them quite insignificant in their actions, very much like
| we've been doing for a very long time.
|
| In that context, I'm kinda skeptical about how often the
| impact of human activity is belittled as supposedly having an
| "insignificant" contribution to global-scale environmental
| changes. Reminds me way too much about how climate change is
| to this day still argued as something "natural", and many
| past human activities that were declared "safe and
| inconsequential" at the time, ended up still having very real
| lasting and global effects, like atmospheric nuclear weapon
| tests.
|
| It makes me wonder how much of that argument is connected to
| religious beliefs along the lines of "Humans could never
| seriously threaten or impact God's creation, and if we do,
| then God intended for it to do so", which sometimes manifests
| in weird ways like considering environmentalism as a form of
| "native evil" [0]
|
| [0] https://www.theguardian.com/environment/blog/2011/may/05/
| eva...
| oefnak wrote:
| How would that work? All metals we harvested, we moved
| maybe a few kilometres higher.
| chmod775 wrote:
| The difference to climate change is that the earth never
| experienced such a rapid change in climate short of
| cataclysmic events in the time periods we can indirectly
| observe, whereas the earth's magnetic field changing
| happened quite often and quite suddenly even before humans
| came around.
| weinzierl wrote:
| _" The deepest hole humans have ever been able to create was
| about 12km deep."_
|
| This interesting: We've sent humans 384400 km away from our
| planet, we've sent an object more than 22E9 km away [1], yet
| we cannot drill a hole deeper than 12 km into our own planet.
|
| [1] http://voyager.jpl.nasa.gov/mission/status
| NikolaeVarius wrote:
| Space has no push back. Digging by definition involves push
| back
| erwinh wrote:
| Interesting project!
|
| Although the name Swarm conjures up a large number of satellites
| it is actually only 3 that make up the constellation:
|
| https://space-search.io/?search=swarm
| bullen wrote:
| I have this theory that the hydrocarbons (which are just dead
| trees) are slowly feeding the magma in the earth when the
| tectonic plates move.
|
| If that's true (although I don't get how that fire burns without
| oxygen) then our use of coal, oil and gas will eventually have
| serious effects?
| iso947 wrote:
| That's a hypothesis, one easily disproven
| ashtonkem wrote:
| If the remaining hole in your theory is finding a way to
| explain a fire burning without oxygen, you might want to
| abandon your theory.
| wongarsu wrote:
| While life developed pretty much right away, multicellular life
| has existed for less than 15% of earth's existence. All of
| earth's coal is from an even more recent period when plants had
| newly developed wood and nothing could decompose it yet.
|
| Earth seems to have been just fine without hydrocarbons for
| most of its existence.
| Loughla wrote:
| I. I just honestly don't understand what you're saying. Or
| where you would've come up with that. Or what the purpose would
| be. Or why you even think this exists.
|
| What are you possibly basing this on?
| giggles_giggles wrote:
| This is clearly someone who thinks the mantle is an actual
| burning fire and doesn't understand that it is molten rock.
|
| "I don't get how that fire burns without oxygen"
|
| Well, it's not a fire...
| foobarian wrote:
| Remember, in the 1800s people thought the Sun was burning
| coal.
| NikolaeVarius wrote:
| How dare people try and use existing knowledge to formulate
| a hypothesis about something that was unknown.
|
| Parent post is just wrong since we know how those processes
| work
| anewdirection wrote:
| That still gives us a 100 million years or so. Even our best
| drilling/mining tech is quite inefficient thankfully. The
| result of burning that energy on the surface will hit us way
| sooner.
| Bjartr wrote:
| Coal, oil, gas fossil fuels are all contained in the earth's
| crust and make up an extremely small fraction of it. The crust
| is just 1% of the volume of the planet and the mantle that the
| rigid plates float on is 84% of the volume.
|
| I'd wager that all the crude fossil fuels in the world might be
| able to have a minor impact on a single decently sized volcano
| if it were all in one spot beneath it, but it's not.
|
| The views above are primarily opinion formed off the cuff
| combined with a few minutes of research. I'm open to being
| shown that I am incorrect.
| akuchling wrote:
| Alanna Mitchell's "The Spinning Magnet" is a good popular-level
| book on the Earth's magnetic field, how it was discovered and
| investigated, and what's currently known about it:
| https://www.indiebound.org/book/9781101985168
|
| Space-based X-ray telescopes also need to take the South Atlantic
| Anomaly into account; data taken while the instrument is in the
| SAA is disregarded.
| [deleted]
| angel_j wrote:
| What is that satellite's probe doing to the magnetic field?
| bArray wrote:
| Haha this is how I first read the title. It should probably
| read: "Swarm satellites probe the Earth's weakening magnetic
| field".
| kburman wrote:
| [deleted]
|
| Edit: I shouldn't have posted it.
| trail-system wrote:
| This has been happening for 180 years.
| subaru_shoe wrote:
| Reddit is leaking again. Take this shit elsewhere
| crispyporkbites wrote:
| All magnets will fail to work so most trains won't run anymore
| and you'll have to use SSDs or tape storage for your computer.
|
| GPS systems will no longer work and Google Maps will spin
| around constantly.
|
| Only babies (and crows) will need to live underground for the
| first 6 months of their lives to ensure they don't develop
| vertico.
| catalogia wrote:
| > All magnets will fail to work
|
| I'm not sure what you responded to since it was removed, but
| I assume it was something to do with the subject of the
| article...
|
| Why would all magnets cease to work if the Earth's magnetic
| field went funky? Surely neither the magnets on my fridge nor
| the magnets in a train's electric traction motors do not
| depend on the earth's magnetic field being oriented any
| particular direction. I'm not sure, but I think AC train
| traction motors don't even have permanent magnets in them.
| Compasses would get messed up though.
| ashtonkem wrote:
| Aren't tapes also magnetic storage?
| furins wrote:
| Geologist here: no. Geomagnetic field reversed thousands of times
| in the Phanerozoic (last 650 My) without any relation with mass
| extinction events. Organisms can deal with this kind of events.
| dmos62 wrote:
| More info? According to Wikipedia, the Phanerozoic Eon has been
| lasting for 541 million years (I rechecked because wasn't sure
| what My meant at first). How would we even detect extinction
| events from a few million years back? Also, hundreds of
| millions years divided by thousands of geomagnetic field
| reversals sounds like very rare (considering the briefness of
| human existance). Also, ecosystem collapses are probably not
| all the same: there's gigantic explosions (a la dinosaur
| killer), there could be ocean acidifaction, etc.
| DataGata wrote:
| There are a lot of good pop science books to read about the
| history of life on earth.
|
| "The Ends of the World" is probably the best one. "The Rise
| and Fall of the Dinosaurs" is also a good one, and it doesn't
| focus purely on the dinosaurs as the title suggests, but
| about how we know how they evolved and existed.
| dwaltrip wrote:
| https://en.m.wikipedia.org/wiki/List_of_extinction_events
|
| https://en.m.wikipedia.org/wiki/Extinction_event
|
| It doesn't look like magnetic pole reversals cause mass
| extinctions.
| narrationbox wrote:
| There have been proposals for an artificial magnetosphere for
| Mars to help with terraforming.
|
| http://www.hou.usra.edu/meetings/V2050/pdf/8250.pdf
|
| https://phys.org/news/2017-03-nasa-magnetic-shield-mars-atmo...
|
| If things truly get bad, we are not entirely out of options
| (though powering the aforementioned shield might be somewhat
| difficult).
| brundolf wrote:
| Can a technological civilization, though?
| akiselev wrote:
| Yes. Some technology and techniques will trickle down from
| defense and aerospace like it usually does. Manufacturing
| will be scaled up and infrastructure retrofitted. Events much
| more traumatic like an atmospheric EMP have been a design
| concern since shortly after we developed nuclear weapons.
| We've got well understood technology to solve any issues that
| come up.
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(page generated 2020-05-28 23:00 UTC)