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  • Let's just take this in for a second.

  • What youre looking at is our first encounter touching the sun!

  • That’s right, thanks to the Parker Solar Probe were up close and personal with our

  • host star.

  • And just one step closer to understanding space weather and so much more about how the

  • Sun impacts life right here on Earth.

  • So the thought of traditionallytouchingthe Sun is vastly different than, let's say,

  • going to the surface of Mars.

  • And that’s because the Sun doesn’t have a solid surface that we can physically touch,

  • even if we had some ridiculouslyfire-radiation proofsuit to make it happen!

  • Instead, the upper atmosphere is an extension of its surface held in place by the overwhelming

  • gravitational pull and magnetic forces of the Sun.

  • The further you get from the core, the weaker these forces become.

  • Eventually reaching a point known as the Alfvén Critical Surface where the atmosphere of the

  • Sun ends.

  • And from here we begin to observe solar wind.

  • Solar wind is made up of streams of charged particles and gas that are propelled by the

  • Sun at millions of kilometers per second throughout the Solar System.

  • These particles can ultimately damage our satellites,

  • like those used for GPS and phone calls.

  • But one the most important questions that Parker needed to answer is where this Alfvén

  • Critical surface is. And in 2021, Parker made a historic discovery.

  • After spending five hours within the upper atmosphere, the probe observed that both the

  • energy and pressure of the Sun’s magnetic field were stronger than that of the particles

  • within it.

  • This meant that the forces from the Sun were strong enough to maintain control of the particles,

  • essentially keeping them close to the center of the sun.

  • However, when Parker rose further away, the reverse was apparent. The forces were no

  • longer strong enough to trap the particles and they were propelled into the Solar System.

  • This was evidence that Parker passed through the Alfvén Critical surface, like flying into

  • the eye of a hurricane, where it’s most calm, and then returning to a barrage of wind.

  • And even more surprising the critical surface is not a perfect sphere. Parker detected that

  • it’s actually made up of spikes and valleys.

  • But overall, scientists finally determined the end of the Sun's atmosphere, at approximately

  • 13 million kilometers from the surface.

  • As Parker continued deeper into the upper atmosphere, it made additional observations

  • of detailed features, like Pseudostreamers.

  • And you might recognize these as the huge ribbon like structures from photos of solar

  • eclipses here on Earth.

  • But one interesting fact that scientists observed within the pseudostreamer region, was a reduction

  • in what we call switchbacks, which might be why we see such unpredictable, powerful bursts

  • of energetic particles from the Sun.

  • In 1995, scientists observed S-shaped kinks in the magnetic field of solar wind near the

  • Sun's poles, thanks to the Ulysses mission.

  • Then in 2019 Parker’s data revealed an unexpected discovery.

  • Before the new insight from Parker, scientists believed that switchbacks were rare and only

  • occurred at the Sun's poles.

  • However, Parker saw familiar signs of magnetic field lines that zig-zagged back and forth

  • throughout the upper atmosphere.

  • And now scientists have evidence to support that switchbacks are common in solar windat

  • least near the Sun’s surface.

  • And since solar wind is constantly flowing from the Sun, scientists think that understanding

  • switchbacks will help us fully understand space weather.

  • As Parker continues to spiral closer to the Sun prepping for its closest flyby in 2025

  • at 6.2 million kilometers, researchers now have a better idea of what to look for.

  • And I have no doubt that well slowly begin to unravel even more about the mysteries of

  • switchbacks, the inner workings of the Alfvén Critical Surface and how the Sun ultimately

  • impacts our satellites and sometimes even life here on Earth.

  • So which discovery do you think was the most important?

  • Let us know in the comments below.

  • Make sure to subscribe and thanks for watching.

Let's just take this in for a second.

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B1 sun parker solar surface solar wind atmosphere

NASA’s Solar Probe Did the Impossible, Here’s How

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    Summer posted on 2022/08/01
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