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hidden magnetic portals around earth

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a favorite theme of science fiction is

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the portal

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an extraordinary opening in space or

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time that connects travelers to distant

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realms

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a good portal is a shortcut a guide

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a door into the unknown

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if only they actually existed

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it turns out that they do sort of and a

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nasa-funded researcher at the university

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of iowa has figured out how to find them

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we call them x points or electron

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diffusion regions explains plasma

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physicist jack scudder of the university

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of iowa

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they're places where the magnetic field

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of earth connects to the magnetic field

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of the sun

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creating an uninterrupted path leading

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from our own planet to the sun's

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atmosphere 93 million miles away

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observations by nasa's themis spacecraft

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and europe's cluster probes suggest that

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these magnetic portals open and close

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dozens of times each day

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they're typically located a few tens of

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thousands of kilometers from earth where

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the geomagnetic field meets the

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onrushing solar wind

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most portals are small and short-lived

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others are yawning vast and sustained

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energetic particles can flow through the

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openings heating earth's upper

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atmosphere

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sparking geomagnetic storms and igniting

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bright polar auroras

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nasa is planning a mission called mms

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short for magnetospheric multi-scale

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mission due to launch in 2014 to study

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the phenomenon

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bristling with energetic particle

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detectors and magnetic sensors the four

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spacecraft of mms will spread out in

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earth's magnetosphere and surround the

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portals to observe how they work

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just one problem

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finding them

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magnetic portals are invisible

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unstable and elusive

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they open and close without warning and

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there are no signposts to guide us in

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note scatter

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actually there are signposts and scudder

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has found them

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portals form via the process of magnetic

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reconnection

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mingling lines of magnetic force from

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the sun and earth criss-cross and joined

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to create the openings

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x points are where the crisscross takes

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place

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the sudden joining of magnetic fields

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can propel jets of charged particles

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from the x point creating an electron

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diffusion region

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to learn how to pinpoint these events

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scudder looked at data from a space

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probe that orbited earth more than 10

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years ago

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in the late 1990s nasa's polar

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spacecraft spent years in earth's

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magnetosphere explained scudder and it

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encountered many x-points during its

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mission

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because polar carried sensors similar to

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those of mms

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scudder decided to see how an x-point

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looked to polar

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using polar data we have found five

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simple combinations of magnetic field

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and energetic particle measurements that

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tell us when we've come across an x

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point or an electron diffusion region

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a single spacecraft properly

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instrumented can make these measurements

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this means that a single member of the

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mms constellation using the diagnostics

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can find a portal and alert other

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members of the constellation

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mission planners long thought that mms

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might have to spend a year or so

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learning to find portals before it could

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study them scudder's work shortcuts the

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process

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allowing mms to get to work without

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delay

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it's a shortcut worthy of the best

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portals of fiction

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only this time the portals are real

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and with the new signposts we know how

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to find them