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hi my name is dr eric christian i'm the

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program scientist for the interstellar

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boundary explorer or ibex mission

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ibex is studying the boundary between

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the solar wind and interstellar space

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there are several boundaries at the edge

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of our solar system

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the closest one we call the termination

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shock that's where the million mile per

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hour solar wind which expands out from

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the sun in all directions in space

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slows down becomes more dense and starts

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to be diverted away before it reaches

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the galactic material

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beyond that is the heliopause the

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heliopause is the boundary that

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separates material of galactic origin on

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the outside from material of solar

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origin on the inside

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and even further out than that we think

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there's another boundary which we call

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the bow shock because the solar system

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is moving quickly through the galactic

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material actually plowing through like a

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snow plow we think the interaction makes

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a sharp jump out in front where the

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where the quickly moving in material has

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you can see that really well in this

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animation where the solar wind is

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streaming out past all the planets and

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it's blown this bubble in interstellar

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space the nearly spherical solar wind

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termination shock bubble and then

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very the the solar wind slows down and

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starts moving back into the tail

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and then the interstellar gas which is

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moving very quickly up here slows down

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in the bow shock and moves around the

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solar system

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you can actually duplicate this in your

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own kitchen sink if you take a stream of

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water

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and bounce it off a flat surface

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what you get is a region close to the

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stream where the water is moving very

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quickly and very straight

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and then suddenly it slows down and you

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actually see an increase in height

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where a shock forms in the water that's

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the equivalent of the solar wind

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termination shock

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and then beyond that shock the water is

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turbulent and flows down into your drain

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and that's the heliopause boundary out

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now one of the reasons why this is

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important is because

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this solar wind that's streaming out to

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the heliopause pushes out galactic

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cosmic rays which are radiation coming

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from distant parts of the galaxy

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and it prevents a lot of these galactic

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cosmic rays from getting into the earth

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or to astronauts on their way to mars

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for example so the solar wind pushing