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Embark on an awe-inspiring journey into the heart of our extraordinary Sun with two captivating stories that explore its enigmatic nature and its incredible future transformation.
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00:00From where we stand, the sun seems so calm and peaceful, but like humans, and basically the whole living world,
00:06the sun has its own phases when it's more or less active.
00:09It's just that the consequences are way bigger and more chaotic when the sun becomes hyperactive.
00:14Let's zoom in to see what's happening up there.
00:17So one of the ways we measure the activity of our star is by counting sunspots on its surface.
00:22Sunspots are dark patches that form when the sun's magnetic field gets all tangled up.
00:27It's simple. The more sunspots, the more active our sun is.
00:32And it seems the sun has been partying like crazy recently.
00:36The number of sunspots scientists have seen is the highest for nearly 21 years.
00:40In June, 163 sunspots appeared on the sun's surface.
00:44The last time we had so many dark patches across the sun was in September 2002, when there were 187
00:51of them.
00:52Uh-oh. It seems this chaotic party is getting closer to its peak.
00:56And that's something we call solar maximum.
00:59How does all this even happen?
01:01The sun's magnetic field is strong and organized at some point.
01:04But as we said, sometimes comes the time when it kinda ends up tangled.
01:08Sort of like a ball of rubber bands that are wound together very tightly.
01:13This also means plasma is rising from the surface, forming loops, and causing a mess in the shape of solar
01:19flares, and something we call coronal mass ejections, CME.
01:23That's when plasma in the sun's upper atmosphere, called the corona, goes crazy, and bursts really strong.
01:30Then at some point, this ball snaps and completely flips and turns the south pole into the north pole and
01:36vice versa.
01:37All this happens every 11 years or so.
01:39So when the sun comes into this phase when it becomes very active, it shoots out hot blobs of plasma,
01:45gets big dark spots as large as planets, and releases powerful eruptions of energy and radiation.
01:52Something fascinating happens when the sun becomes more active, a thing called plasma waterfall or polar crown prominence, PCP.
02:00It's like a mini eruption that starts on the sun, and it seems like it tries to get away, but
02:05then the sun's magnetic field pulls it back before it can escape into space.
02:09And this plasma waterfall's really spectacular.
02:12It goes up to 62,000 miles above the surface.
02:16It's like you stack eight Earths on top of each other.
02:20Then there's something called a polar vortex.
02:23It's like a gigantic halo of plasma that rotates around the sun's north pole really fast.
02:29This vortex happens when a large tentacle of plasma snaps apart and falls back toward the surface, similar to how
02:35a plasma waterfall forms.
02:38Scientists don't know why this plasma stays above the sun's surface for so long.
02:42And one of the cool examples of CMEs was a giant one in the shape of a butterfly in March
02:48this year.
02:48It got such an unusual shape because it exploded on the side of the sun we couldn't see.
02:53So it was impossible to fully measure how strong it was.
02:57Fortunately, that one didn't explode in our direction.
03:00But it might have hit Mercury a little bit.
03:02And it's possible it knocked off some dust and gas since Mercury has a weak magnetic field.
03:08All this sounds cool in theory, but it's not such good news for us.
03:12Because of all this, we might experience more intense solar storms that can, again, lead to geomagnetic storms on Earth.
03:18And these don't just sound alarming.
03:20They indeed are.
03:21They create chaos and disrupt the magnetic field of our planet.
03:25Geomagnetic storms can create beautiful northern lights, true.
03:28But we'd all rather enjoy such beauties as the aurora borealis in regular conditions.
03:33Or just watch a good old sunset above the ocean.
03:37It's not that every solar storm will necessarily hit Earth, even if there are more of them.
03:42To reach our planet, they must be pointed in the right direction at the right moment.
03:46But if that happens, the storm can ionize the upper atmosphere and bye-bye our communications.
03:51It can cause temporary blackouts for systems such as GPS and radio.
03:56It isn't necessarily a big problem on its own, but it can be very dangerous if it happens at the
04:01wrong time, like during a tsunami or an earthquake.
04:05The storms can also damage electrical infrastructure, like rail lines and power grids.
04:10If you're on a plane at that time, you might be exposed to higher levels of radiation.
04:15It's still not clear how dangerous that will be for you, but it can be a serious problem for astronauts
04:20in space.
04:22When solar storms mess with the magnetic field, this can affect the migrations of some animals, such as sea turtles,
04:28whales, and birds.
04:30Since things in the animal kingdom mostly work in the natural order, who knows how these animals go through or
04:36even survive such changes?
04:38And when the sun is at a maximum of its activity, satellites in space are in trouble too.
04:44We have more satellites in space than ever before.
04:47And when the upper atmosphere becomes denser because of all these changes, this can push satellites in different directions.
04:54They might crash into one another or some can even fall back to Earth.
04:57Which, again, is only cool in movies with superheroes who can relatively easily deal with this stuff.
05:04Hopefully, we'll avoid a massive solar storm like the Carrington event.
05:08The story was similar.
05:09In August 1859, astronomers across the globe watched how the number of sunspots was getting bigger and bigger.
05:16A man named Richard Carrington was among them.
05:19At the beginning of September, he was sketching the sunspots when, out of a sudden, he was blinded by a
05:25flash of light.
05:26It lasted around five minutes, but it was spectacular.
05:30He later described it as a white light flare.
05:33It was a very strong coronal mass ejection CME, and in only 17.6 hours, this storm crossed the long
05:40way between the sun and our home planet, 90 million miles, and unleashed its force on us, even though this
05:46usually takes days.
05:49And when this storm started, telegraph machines across the world sparked.
05:53Operators got electric shocks, and paper even caught fire.
05:57People were really scared and confused, because they had never seen such bright skies before.
06:03Some even thought it was the end of the world.
06:05The next day, telegraph workers still couldn't work properly, because Earth's atmosphere was still charged.
06:12They even managed to send messages using the auroral current instead of regular electricity.
06:18But it brought something incredible.
06:20Two stunning auroras in the sky.
06:22People in Hawaii and Cuba could see beautiful northern lights, while those as far north as Chile could see the
06:28southern lights.
06:30It's all slowly but steadily escalating.
06:33Take solar flares, for example.
06:35These are powerful bursts of energy from the sun.
06:37In 2022, there were five times more of these flares compared to the previous year.
06:42Plus the strongest ones, X-class flares, have been getting stronger and more common than before, too.
06:48And this might be way more extreme than anyone thought.
06:51Plus, it's likely to start a little bit earlier than we predicted.
06:55Scientists first thought the peak would happen in 2025.
06:59But it seems it could even occur by the end of 2023.
07:03We can't completely protect ourselves if a solar storm hits us directly.
07:07But we can still do some things, like ground planes, adjust the paths of satellites in space, and try to
07:12make sure vulnerable infrastructure stays safe.
07:15To do all this, we need better solar weather forecasts to help us get ready for the worse.
07:21All this might sound very bad at first.
07:23But don't worry, solar flares won't destroy our planet.
07:26They do send charged solar material toward us at pretty high speeds.
07:30But it's not like we're completely doomed if these things hit us.
07:34Our planet won't leave us unprotected.
07:36We still have the atmosphere and magnetic field that keep us relatively safe.
07:41Our thick atmosphere is like a shield that blocks radiation that might harm us.
07:45So these solar flares can mostly affect technology, but they won't destroy Earth.
07:50I guess we have our own superheroes after all.
07:53Hey, take a look.
07:55It's Earth.
07:56It's sailing through our solar system.
07:58And torrents of hot charged particles are crashing into it at a speed of around 1 million miles per hour.
08:05Those particles are called the solar wind.
08:08And it comes directly from the sun.
08:11How come you don't feel it?
08:13That's because Earth's magnetic shield protects you.
08:16It kind of deflects the harshest gusts of this wind.
08:19And nothing more than a light breeze gets through the planet's atmosphere.
08:23Every now and then, you even get to see Aurora Borealis.
08:27Beautiful light shows caused by solar winds for all your troubles.
08:32Unfortunately, everything can and will change with time.
08:36Earth's magnetic shield won't be able to protect the planet infinitely.
08:41And solar winds are only getting stronger because our star is gradually approaching its inevitable demise.
08:48Oh, yes.
08:50The sun, which has been providing us with heat and light for millions of years, shines on borrowed time.
08:56In 5 to 7 billion years, it will swell into another type of star altogether.
09:01The sun will become a red giant.
09:03When it happens, the view will be spectacular and breathtaking.
09:08But inside the solar system, it will lead to a catastrophe.
09:13What do you need to know about red giants?
09:16They're enormous.
09:17You think the sun is large.
09:19Well, maybe it is, with its diameter of more than 865,000 miles and weight as great as that of
09:26300,000 Earths.
09:27But that's nothing compared to a red giant.
09:30To become one, the sun will have to grow to more than 100 times its current size.
09:37Scientists claim that the range of potential outcomes of such catastrophic scenarios
09:42usually depends on the size of the planet and the state of its parent star.
09:47Thanks to Earth's size and the distance to the sun, it's unlikely to get devoured completely,
09:53unlike Mercury and Venus.
09:55But the sun is bound to make our planet unlivable.
09:58See for yourself.
10:01A team of astronomers has calculated that solar wind will intensify in the next 5 billion years or so.
10:07That's when the sun is supposed to run out of its fuel, hydrogen.
10:11At the moment, the core of our star is about 74% hydrogen.
10:15But when the sun burns through most of it, helium will become its main source of fuel.
10:22After our star has consumed almost all of its hydrogen, its core will become way smaller and much hotter.
10:29This will intensify nuclear reactions going on in the core.
10:32With this additional energy, the outer layers of the sun will expand.
10:38You can probably guess that with a radius 200 times greater than the current one,
10:43the sun will soon swallow Mercury and Venus.
10:46As for our home planet, there are two potential outcomes.
10:50Either Earth's orbit will expand far beyond the sun's reach and we'll all freeze.
10:55Or our planet would be pulled toward the star and engulfed by its unbearable heat.
11:02Imagine this.
11:03The sun is growing bigger and bigger in the afternoon sky with every passing day.
11:08It balloons into a monstrous red sphere.
11:12The solar wind is so powerful now that it starts to erode the magnetic shield of our planet.
11:17Soon, there's nothing that can protect us from the unforgiving sun's rays.
11:22The solar wind blows the largest part of Earth's atmosphere into space.
11:26And with it, we lose the last protection from tough stellar radiation.
11:31Even if some life on our planet has managed to survive this long,
11:35it will be wiped off the face of the Earth.
11:39In the past, a similar thing happened to the Martian atmosphere.
11:43At the same time, Mars has never had a large-scale magnetosphere.
11:48Unfortunately, recently scientists have found out that our magnetic shield won't be enough to protect Earth forever.
11:54And the more time passes, and the older our sun becomes, the more damaging its solar wind gets.
12:02Anyway, what'll happen after the sun swallows Mercury, Venus, and, probably, our beautiful blue Earth?
12:09It'll keep expanding for another billion years or so.
12:13After that, our star will collapse into a white dwarf.
12:18A white dwarf is what's left after a star has run out of its fuel.
12:22These space objects are among the densest out there.
12:25They're also pretty dim.
12:27Massive stars usually go supernova,
12:30but those with a low or medium mass eventually turn into white dwarfs.
12:35Around 97% of all stars in the Milky Way galaxy will become white dwarfs in the end.
12:40If it happens to our sun, it'll keep smoldering for another couple of billions of years,
12:46and then its light will flicker out for good.
12:50Anyway, if, by some miracle, Earth manages to survive the sun's transformation into a red giant,
12:57it'll have to exist in a very different solar system.
13:01If the star doesn't swallow our planet, its gravitational pull on Earth, as well as other planets, will weaken.
13:07It'll cause our home planet to drift away from the sun.
13:11But, at the same time, the solar radiation the newly born red giant will start to ooze
13:16will get way more intense than it is now.
13:20But the main problem is that red giants aren't only incredibly large.
13:25They're also unbelievably hot and shine thousands of times as bright as the sun.
13:30Most of the material the future red giant sun will eject,
13:34which can be half the mass of the present-time sun,
13:37will get to the outer edges of the solar system.
13:41If it happens, even asteroids will melt, losing most of their mass.
13:46Their rocky nuclei will be the only thing left behind.
13:51Meanwhile, at the moment, the sun is still a yellow dwarf.
13:55It's a ginormous ball of gas and scorching plasma.
13:59The star's core takes up to 25% of its entire radius.
14:04Inside, gravitational forces create incredible temperatures and pressure,
14:08which make hydrogen fuse into helium.
14:11The core itself has a temperature of 27 million degrees Fahrenheit.
14:16All that energy moves to its radiative zone.
14:20It takes, on average, 170,000 years for the energy to get all the way from the core to the
14:26next,
14:27convective, zone.
14:29There, bubbles of hot plasma float upward and end up at the sun's surface.
14:35That's where a visible 300-mile-thick layer starts.
14:39This gassy zone is called the photosphere.
14:42It gets heated up to 10,000 degrees Fahrenheit.
14:45This layer consists of granules,
14:47cells of plasma 600 miles in diameter each.
14:52Moving further, we get to the crown.
14:55That's the star's thin atmosphere.
14:57Shockingly, it's even hotter than the surface of the star.
15:01Temperatures there reach 3.5 million degrees Fahrenheit.
15:05Scientists suspect that powerful bursts of heat from the sun
15:08might have something to do with this unique phenomenon.
15:12To imagine how big the sun is,
15:15it's probably enough to know that the star has a diameter of 109 times the size of our planet.
15:21You could also fit 1.3 million Earths inside the sun.
15:25Or, if you had nothing better to do,
15:27you could flatten 11,990 Earths
15:30and use them to cover the surface of our star.
15:33The sun also accounts for more than 99% of all the mass in the solar system.
15:39But there are way, way bigger stars out there.
15:43If you decided to replace the sun with the largest star people know about,
15:47the giant would reach Saturn.
15:50The sun is a middle-aged star.
15:53Astronomers believe it appeared about 4.59 billion years ago from the solar nebula.
16:00Different parts of the sun rotate at different speeds.
16:03To observe this phenomenon, you can concentrate on a sunspot
16:07and start tracking its movement across the surface of the star.
16:10Just don't forget to protect your eyes.
16:12Areas at the sun's equator need about 25 days to finish one rotation,
16:17while regions near the poles need 36 days or so.
16:21As for the inner parts of the sun, they need no more than 27 days.
16:27The sun is traveling right now, and fast.
16:30It's moving at a speed of 137 miles per second.
16:34It takes the star 225 to 250 million years
16:38to complete its orbit around the center of the Milky Way.
16:42By the way, the distance between Earth and the sun isn't always the same,
16:47because Earth's orbit around the sun is elliptical.
16:50So, this distance ranges from 91 to 94 million miles.
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