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there are a few ways to think about the

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edge of the solar system

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one is with the extent of the solar wind

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this is the constant flow of charged

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particles gushing out of the sun at a

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million miles per hour and bathing the

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planets the wind forms a giant

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protective bubble around our solar

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system known as the heliosphere

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this huge region surfs through the milky

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way shielding us from interstellar

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radiation and creating an environment

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that helps life on earth to flourish

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but its borders aren't fixed around 11

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billion miles from earth far past the

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planets solar wind pushes against

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interstellar space

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scientists have been monitoring this

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boundary over the past decade and

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they're seeing it change with the sun's

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activity

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[Music]

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roughly every 11 years the sun's

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magnetic field ramps up

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this is known as the solar cycle and at

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the peak the sun's magnetic poles flip

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north becomes south and vice versa

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this cycle causes the sun's activity to

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sway from calm to turbulent with an

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abundance of flares and eruptions which

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in turn affects the solar wind

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changes from the sun can make the solar

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wind gust hard when it does the

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heliosphere expands like a balloon

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over the past solar cycle scientists

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mapped what that looked like

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to understand these maps you need to

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know how we observe the edge of the

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solar system

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scientists use nasa's interstellar

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boundary explorer or ibex about the size

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of a bus tie and in the orbit around

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earth ibex maps the heliosphere with a

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process similar to sonar but instead of

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using sound to detect objects it uses

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the echo of solar wind variations

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for example starting in 2014 there was a

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huge and prolonged increase in solar

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wind pressure

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nasa spacecraft near earth detected

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solar wind gusting 50 harder than

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previous years

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after traveling outward for a year

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solarwind hit the edge of the

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heliosphere

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first the termination shock and then it

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entered the heliosheath that's encased

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by the heliopause

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solar wind particles spent another year

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or so in this region

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some collided with interstellar gases in

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the heliosheath and turned into

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energetic neutral atoms or enas

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enas travel in all directions

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some even back toward earth and between

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2017 and 2019 a few of the returning

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enas reached ibex

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an echo of where the boundary is and

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if you cut the heliosphere and laid it

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out onto a flat surface

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this is what you would see

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this is the nose and this is the tail

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the nose shows high ena fluxes which

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indicate a strong gust of wind and the

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heliosphere ballooning

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from tracking this expansion scientists

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found that the nose and tail were not

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symmetrical

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if we compare the maps earnings from

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that big 2014 solar wind increase

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have returned from the nose but they

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haven't returned from the tail yet

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suggesting that the tail is much farther

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away from the sun than the nose

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this indicates that the heliosphere

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looks more like a comet rather than a

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round bubble

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having a full solar cycle of

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observations of the heliosphere opens

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doors to understanding the only

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environment we so far know can support

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life and there have been a few surprises

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beyond the heliosphere near the nose

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there was one region that took two years

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longer to respond to the 2014 increase

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of solar wind

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scientists think these enas bounced out

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of the heliopoles and into interstellar

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space before heading back toward earth

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these are signs that we're still

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learning about the quirks of our

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heliosphere but one thing's for sure

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these characteristics could tell us

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about the key ingredients for life

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around a star