Everything About The Sun ️ Science Channel

[00:00:01]And in an unremarkable corner of our galaxy, the Milky Way, lies the sun. Our closest star, a dazzling sphere of intense light, too bright for the naked eye.

[00:00:21]But strip away that glare, and the sun transforms [music] into a giant ball of superheated gas.

[00:00:30]dominating our cosmic stage.

[00:00:36]>> The sun is really the star of the show.

[00:00:38]The sun is the parent of the whole solar system.

[00:00:43]It provides its children, the planets, [music] with everything they need. We depend on the sun for energy, for light, for [music] warmth. We would not exist without the sun.

[00:00:57]The sun generates heat [music] and light, the energy source for all life on Earth.

[00:01:04]>> All of the energy that my body uses, literally what I'm doing to talk to you right now, came from the sun. The sun truly is the creator of all of the life around us.

[00:01:15]>> The sun is a constantly exploding nuclear bomb, violent and essential.

[00:01:23]Our entire existence is powered by the energy emitted in those nuclear reactions in the sun. We are here because of the light from the sun. We are here because of those nuclear reactions. [music] And no aspect of our existence could persist if it wasn't there.

[00:01:42]>> Light is one of the basic building blocks of the [music] universe.

[00:01:52]I [music] find light to be probably the most amazing thing in the universe. It's so important in everything. I mean, it's everything. It's everywhere. So, it's such a fundamental part of everything that exists.

[00:02:05]>> Fundamental and fast.

[00:02:09][music] The fastest thing in the cosmos.

[00:02:12]Traveling at 186,000 m per second.

[00:02:19]The sun's about 93 million miles away from us. So going at 186,000 m per second, that's about 8 minutes. But those 8 minutes are just the brief last leg of its incredible journey.

[00:02:37]It may have [music] taken the light as much as a million years to escape from the sun's raging [music] interior.

[00:02:45]Which means the light we're seeing right now was created long before our ancestors left the plains of Africa.

[00:02:57]When I first learned this fact, I was already a practicing scientist. I'd never really thought about that. And on first glance, it just blew me away.

[00:03:05]>> Right now, the light reaching me from the sun was produced before there was even human civilization. And yet, the minute it gets to the surface of the sun, it races away and is here 8 minutes after that. It's an incredible [music] idea.

[00:03:18]>> The ride that any photon takes to get to my eyes when I look up at the sun is an amazing one.

[00:03:26][music] >> That ride starts deep in the belly of our star.

[00:03:32]If we could open up the sun, we'd see layers of dense hydrogen gas hundreds of thousands of miles deep.

[00:03:42]And at its [music] center, the core, the sun gives birth to light.

[00:03:50]Forged in one of the most violent reactions in the universe, nuclear fusion.

[00:04:03]The specific nuclear reaction that powers the sun is fusion. Fusion of hydrogen into helium. You take two hydrogen atoms, you ram them together, and what's left over is a helium atom.

[00:04:13]>> It sounds simple enough, but it's not.

[00:04:18]>> It's actually hard to get two atoms to fuse. Uh, two protons have the same charge. They're both positively charged.

[00:04:23]They want to repel each other.

[00:04:27]>> Protons don't like to get close together. They have to come together with a huge amount of energy or velocity to get close enough to begin to fuse.

[00:04:37]And that's very very rare.

[00:04:40]>> To force protons together takes immense amounts of heat and pressure generated by the invisible hand of gravity. The sun contains 99.8% of all the matter in the solar system.

[00:04:58]That's a lot of mass. All that mass pulls the sun together with unimaginable [music] gravitational force.

[00:05:09]>> But with gravity crushing things down, things get close enough together and nuclear fusion happens.

[00:05:16]>> In this nuclear compactor, hydrogen atoms slam together 100 million quadrillion quadrillion times each second.

[00:05:30]Some of these collisions are so powerful that atoms fuse, releasing energy.

[00:05:37]When the protons come together to bind together, they lose a little bit of mass [music] and that mass gets converted into energy. And every second of every day, about 5 million tons of stuff is being converted to energy.

[00:05:53]It's amazing.

[00:06:01]Each collision creates a tiny burst of energy, a packet of light, impossibly small and incredibly powerful.

[00:06:13]Somehow, our photon [music] will deliver its energy to Earth where it will power the planet and make life possible.

[00:06:22]But right now, it's nothing like [music] the light we see.

[00:06:27]It has massive amounts of energy and is [music] deadly.

[00:06:37]The light we see from our [music] star is old. It's much older than the 8 minutes it takes to get from [music] the sun to Earth.

[00:06:47]That short leap across space is the end of a long hard journey that starts deep inside our sun. When we look at the sun, we say how beautiful, how elegant, and how simple. Light is formed in the sun and it shines and lights up our world.

[00:07:04]Well, not so fast. It's actually very complex.

[00:07:10]The journey starts in the immense heat [music] of the sun's core.

[00:07:19]Crushed together by the sun's enormous gravity, atoms smash into each other and fuse, releasing a tiny packet [music] of energy.

[00:07:32]A photon of light, far smaller [music] than an atom and with no mass, photons travel faster than anything else, and they [music] never stop moving.

[00:07:51]Photons don't just come from the core of stars.

[00:07:57]So where does light come from? The short answer is matter makes it. And the amount of light that it creates depends on its temperature.

[00:08:06]Every piece of matter in the universe above absolute 0 degrees produces light, including humans.

[00:08:16]>> We humans are emitting light all the time because we're alive. We're warm.

[00:08:20]We're not at a zero temperature. So, in fact, we are emitting infrared radiation, often called heat radiation.

[00:08:27]But all matter emits light.

[00:08:29]>> Even someone as cool as me, I'm creating light right now.

[00:08:36]The light we see can be split into the colors of the rainbow. Each color is photons of light with slightly different amounts of energy.

[00:08:48]And what we can see is only a fraction of the light spectrum.

[00:08:54]Our eyes are actually imperfect detectors. We know about visible light, the type of light that our eyes are sensitive to, but that's only a small range of energies. Light comes at higher and lower energies than we can detect.

[00:09:08]>> Using special cameras, we can see the infrared [music] light that humans emit.

[00:09:14]This infrared light has less energy [music] than the visible light we normally see.

[00:09:23]Ultraviolet light, X-rays, and gamma rays are too energetic to see.

[00:09:36]The fast hot sun generates all forms of light.

[00:09:42]But in the nuclear furnace of the sun's core, every photon starts out as a gamma ray, the most energetic form of light in the universe.

[00:09:54]>> And when a nuclear reaction happens, it emits an amazing amount of energy.

[00:09:58]Energy much much bigger than visible light. Gamma rays. we call literally almost a million times or at least 10,000 times the energy of the light we see.

[00:10:10]>> Gamma rays can transform and even kill.

[00:10:14]>> There's a reason why gamma rays turn Bruce Banner into the Hulk. Gamma rays are a very dangerous form of light. They can travel into your body and when they interact with the matter, they can break apart atoms.

[00:10:27]Fortunately for us, our gammaray [music] photon can't hit straight out of the sun.

[00:10:40]If the sun were not this hot ball of gas, then upon being created, a photon would immediately escape from the sun and it would be a gammaray photon, a very energetic photon, not very good for life on Earth.

[00:10:55]After its birth as a gammaray, our photon starts to race [music] out from the sun's core at the speed of light.

[00:11:06]But it encounters an obstacle course of epic proportions.

[00:11:12]A journey that should take seconds slows to a cosmic crawl.

[00:11:19]It takes on average about a 100,000 years for a photon to make it from the middle of the sun where it was created to the outermost edge where it gets emitted into space. 100,000 years. If it had traveled in a straight line unimpeded, it would have taken 2 seconds.

[00:11:38]What could possibly slow the journey of a photon moving at the speed of light?

[00:11:45]Something slams the brakes on.

[00:11:49]Huge, hot, dense, so powerful, it doesn't just slow light, it transforms [music] it.

[00:12:05]November 5th, 2018, an explosive cloud of plasma hits the Parker Solar Probe as it orbits just 15 million miles from the sun.

[00:12:18]We have this fleet of spacecraft out there viewing the sun and they're also under attack by the sun.

[00:12:26]There are explosions coming from its surface. It's not just light, but explosions of hot plasma and the Parker Solar Probe got blasted and yet it survived.

[00:12:39]A huge blast of high energy charged particles launches into the solar system at millions of miles an hour.

[00:12:48]A coronal mass ejection, but our solar scout is prepared for the onslaught. The Parker Solar Probe gets very close to the sun and it has a heat shield to protect it. But if it gets hit by a coronal mass ejection, it has to be protected against that as well. And so it's been radiation hardened to survive such an impact.

[00:13:13]Could these blasts pose a danger to our planet?

[00:13:18]A coronal mass ejection accelerates subatomic particles. And it's not a little bit of particles. It could be up to a billion tons of them screaming across the solar system at high speed.

[00:13:31]And this is something we need to take very seriously.

[00:13:36]>> To understand these dangerous blasts of plasma, we have to look at their source, an area around the sun known as the corona.

[00:13:48]The sun's corona is kind of like its atmosphere. You can think of the sun itself as being a ball of gas, and then outside of that is this ethereally thin gas stretching out for millions of miles.

[00:14:00]The corona is a difficult thing to study because the surface of the sun is so bright it blocks our view.

[00:14:09]We can only see the corona during a total solar eclipse when the moon blocks the sun's bright glare.

[00:14:18]Astronomers though, we're impatient. We don't want to have to wait for a total solar eclipse, which only happens once or twice a year. So, we figured out a way to make an artificial one, and it's really simple.

[00:14:31]>> One member of the solar fleet has it covered. Our solar sentinel, SOHO, creates its own eclipse by obscuring the blinding sun with a circular plate in front of the probe's camera.

[00:14:46]>> Sometimes the best solution is the simplest solution. you know, instead of trying to make a sensor that could actually see the full dynamic range of the sun's light, you know, why not just block out the light that we don't need?

[00:15:01]In July 2012, SOHO spotted a huge chunk of the corona blasting off into the solar system.

[00:15:11]Seconds earlier, another probe monitoring the solar surface spotted a bright flare.

[00:15:19]Were these events connected?

[00:15:22]>> If a flare goes off, it can disrupt those loops. And if you get the right kind of disruption, the whole thing can just blow open. And then you have a tremendous amount of billions of tons of hydrogen uh blown off into interplanetary space. And that's a coronal mass ejection.

[00:15:42]>> Coronal mass ejections are solar flares on steroids.

[00:15:47]If a solar flare was a firecracker, a coronal mass ejection is more like an atom bomb.

[00:15:59]>> And if a coronal mass ejection comes our way, it hits hard. The first thing it does is it compresses Earth's magnetic field and then it wraps around the Earth and this causes the magnetic field itself to rearrange, reconnect and streams of particles travel down those magnetic fields toward our poles and impact the atmosphere.

[00:16:22]>> Our shields are up but uh they are able to penetrate our shields and our shield being our own magnetic field. Once they breach our defenses, the particles of a coronal mass ejection can wreak havoc.

[00:16:37]In August of 1972, tensions were running high in Vietnam.

[00:16:48]Two dozen sea mines detonated at the same time when their magnetic sensors were tripped. A satellite was lost because of the electromagnetic pulse that ripped through it. and an Air Force sensor detected what looked like a nuclear explosion somewhere here on the planet.

[00:17:05]>> Fortunately, scientists quickly found the real culprit.

[00:17:10]A coronal mass ejection had ripped through the Earth's magnetic field and triggered magnetic sensors.

[00:17:18]The crisis soon deescalated.

[00:17:23]The sun is an immense ball of plasma 860,000 miles across. We are not going to be able to stop it from doing whatever it wants to do.

[00:17:32]>> What we can do is learn to predict what's going to happen. So, we're doing that now.

[00:17:43]Our new fleet of solar observers are our first line of defense.

[00:17:50]The sun is a little over 90 million miles from Earth. It takes light a little over 8 minutes to get from there to here. As rapidly as a coronal mass ejection is traveling, it still takes a few days to get here.

[00:18:05]We can watch the sun to see is there going to be an event or is an event starting. And these satellites can then tell us, hey, you better be careful. You might need to batten down the hatches on Earth.

[00:18:19]But there may be an earlier clue the fleet can watch out for.

[00:18:23]Vast dark regions moving across the solar surface called sunspots.

[00:18:30]We know that this is the wind up before the release. This thing is getting ready to blow.

[00:18:41]In November 2019, the solar fleet watched as Mercury sailed across the sun. [music] >> Mercury is the closest planet to our sun in our solar system. So, it's on the front line receiving all of this radiation, an incredible amount of energy, and it's such a tiny planet.

[00:19:01]>> Temperatures on the innermost planet surface reach 800° F.

[00:19:08]But scientists discovered [music] something unexpected on Mercury.

[00:19:13]Frozen pools of water hidden in its craters.

[00:19:19]>> It's one of the last places in the solar system you might expect to find ice on Mercury, one of the hottest planets in the solar system.

[00:19:25]>> Despite the overall really high temperatures across the whole planet, there are regions like typically deep within craters that are permanently shadowed. So, there's never direct sunlight on those regions of Mercury, and you can keep things as cold as ice in those craters.

[00:19:42]>> But where did the ice come from?

[00:19:45]>> When we first saw that there was ice on Mercury, we thought something must have brought it there. Something like a comet, which is made out of ice.

[00:19:53]But there's a new idea that maybe the materials that make this ice are actually coming from the sun.

[00:20:04]The sun creating ice sounds strange, but recent research shows it's not as crazy as it seems.

[00:20:13]We often think of space as being empty, but in fact, we are bathed in a wind, a million mph wind of high energy particles from the sun all the time, the solar wind.

[00:20:25]A stream of subatomic particles called protons constantly flow out from the sun in all directions, bombarding the planets of our solar system. [music] The solar wind is so strong when it hits Mercury that it can break down some of the minerals and rocks on its surface into their constituent parts. And those parts, especially if they have oxygen in them, can go to reform and form water, which if it forms in the right place, can then stick around.

[00:21:00]Protons in the solar wind combine with oxygen to form water molecules. They condense and freeze in craters, which never sees sunlight.

[00:21:12]So even on the sun's closest neighbor, ice builds up.

[00:21:18]But the solar wind doesn't stop at Mercury.

[00:21:24]>> The solar wind has a tremendous impact on the worlds of our solar system. We think it's responsible for the planet Venus becoming this hell hole of heat.

[00:21:34]>> Up until as recently as 700 million years ago, Venus was a lush water world with conditions suitable for life.

[00:21:45]But the solar wind blasted away the water vapor and oxygen from Venus's atmosphere, leaving carbon dioxide to dominate, trapping the sun's heat and causing surface temperatures to skyrocket.

[00:22:01]Mars was once habitable, too.

[00:22:04]But the solar wind quickly took care of that as well.

[00:22:10]We believe that billions of years ago, Mars had an atmosphere and had oceans and rivers. It looked a lot like Earth.

[00:22:17]It was gorgeous. But that solar wind stripped away the Martian atmosphere and turned it into the barren wasteland that it is today.

[00:22:28]>> And Earth is in the line of fire, too.

[00:22:32]It's bombarded every day with solar wind particles.

[00:22:37]So, how has life survived?

[00:22:41]>> One of the things we really take for granted is how well protected we are here on the Earth. The atmosphere absorbs a lot of harmful things from space and from the sun as well. But also, our magnetic field deflects the solar wind around us and we still have an atmosphere.

[00:22:55]And when the charged particles come from the sun, the magnetic field lines trap those charged particles and redirect them to the poles of the planet. The physical effect, the direct physical effect of getting bombarded by these particles, they can generate the aurora borealis, the northern lights. And these are spectacular and beautiful.

[00:23:15]Auroras are beautiful, but they're also the front line in the battle between Earth and the solar wind.

[00:23:24]Without our protective shield, we'd suffer the same fate as Venus or Mars.

[00:23:30]But there is a mystery surrounding the solar wind.

[00:23:34]>> One of the things we know about the solar wind is that it is hugely energetic million miles an hour. What gives it that energy?

[00:23:42]>> Astronomers think the source of the solar wind lies in the inner corona.

[00:23:48]The atmosphere of the sun revealed by our solar sentinel SOHO.

[00:23:54]SOHO's data shows that near the sun's surface, the wind speed is close to zero.

[00:24:02]But by the time the wind gets to the outer corona, it accelerates to 720,000 mph.

[00:24:11]>> Something happens mysterious between the surface of the sun and the corona that gives a punch to the solar wind.

[00:24:22]Why do some storms hurdle from the sun so much faster than others?

[00:24:31][music] Scott Macintosh believes he might have the answer. It [music] all comes from a new and revealing set of images of the sun taken by the state-of-the-art [music] SDO satellite.

[00:25:15]It's a brand [music] new camera in space taking a highresolution image of the sun in 10 different wavelengths of light once [music] every 10 seconds.

[00:25:36]It's the content [music] in those images and the frequency of them, how often they happen, that's really going to help us push through and understand better space weather storms.

[00:25:51]>> In these new images, Scott has noticed something.

[00:25:55]It may explain why some storms are so much faster than others.

[00:26:00]He's been focusing his attention here, the sun's superheated corona.

[00:26:06]This is the area of the sun's atmosphere. 20 times hotter than its surface.

[00:26:17]This superheated layer holds in all the loops of magnetic power and all the hot plasma.

[00:26:28]So you see here the corona in super slow-mo.

[00:26:33]And what we're looking at is that detailed evolution of all these chronal loops. These are fibers of magnetic fibers that make up the whole corona.

[00:26:41]The corona is like a pressure cooker.

[00:26:43]And these loops are like the top of the pressure cooker.

[00:26:48]Just watch. This is a chronal mass ejection in action back at the sun. If you watch really closely, boom. You see that? As the material rips away, you get these two very dark patches either side of the active region. Watch again closely.

[00:27:03]Boom. You see them? The corona gets instantaneously dark over hundreds of thousands of kilometers and then it slowly patches in. These, as we call them transient coronal holes, may provide a clue or the energy source for these super fast CMEs.

[00:27:22]>> These transient coronal holes, virtually invisible until 2010, are part of a mechanism that can supercharge a CME.

[00:27:32]ripping a hole in the corona, tapping into the sun's energy back down on the surface.

[00:27:38]>> If you watch closely, the coronal loops that just happened to be there before the corona erupted just disappear. In fact, they don't just disappear. It seems like you rip into the lower part of the atmosphere.

[00:27:53]All that energy that was keeping the cron at a million° now has an avenue to escape. You've basically opened the gates of hell.

[00:28:06]>> These gates are the heart of space weather.

[00:28:10]Through them, all the power of the sun has a channel to escape.

[00:28:25]So, it's this tapping in of this reservoir of energy, this boundless amount of energy that may give the CME its kick. The thing that gives the CME its kick to 1,000 km a second that lets it get to Earth that little bit faster than we can currently understand.

[00:28:42]Scott hopes to use these weird dark patches as a way of answering the billiondollar question, will a storm hit today or tomorrow?

[00:29:00]Satellites are a key part of our vulnerable infrastructure. Our modern world is built on them.

[00:29:09]Navigation, communication, everything from warfare to banking relies on them.

[00:29:20]Satellite electronics can be destroyed by space weather storms.

[00:29:35]But space weather can also affect our atmosphere, plucking a satellite out of its orbit and sending it crashing to Earth.

[00:29:54][music] A remote Arctic monitoring station is home to an ambitious project.

[00:30:03][music] A project to protect our civilization 215 miles inside the Arctic Circle. It's a good place to test something that could end up protecting our satellites.

[00:30:36]Norway, Northern Norway, is very good for these types of experiments because we're in the high polar region.

[00:30:43]And it's in the high polar regions that the Earth's magnetic field comes down to the ground almost vertically. And this is very important especially when you're doing radar experiments so that you can map along the magnetic fields out into space several thousand kilometers and that's not possible anywhere else on the earth.

[00:31:07]Mike Kosh is attempting to do something artificially invisibly that happens naturally up here.

[00:31:23]The aurora is caused by particles coming from space crashing into the top of the Earth's atmosphere. These particles come from the sun. They get trapped on the Earth's magnetic field. And because the magnetic field in polar regions comes down to the earth's surface vertically, the particles can track along those magnetic field lines down in the polar regions into the atmosphere.

[00:31:51]When they collide with the oxygen and nitrogen that we are breathing, they activate those gases which causes optical emissions to appear. Red and green typically is for oxygen and blue is for nitrogen.

[00:32:07][music] The aurora is just the most beautiful and surreal experience.

[00:32:19]The same process that creates the aurora happens much more powerfully during a solar storm.

[00:32:28]Mike is using this massive dish to precisely measure how a solar storm changes our atmosphere and the threat that this poses.

[00:32:39]When that wave of material comes towards the earth, it heats the atmosphere and that causes the atmosphere to expand.

[00:32:50]This expansion makes the region of the upper atmosphere satellites fly through denser.

[00:32:57]The resulting extra drag can have serious consequences for our satellites.

[00:33:04]During a big storm, this expansion can increase the density of the gases here 10fold.

[00:33:13]The result can be catastrophic for any satellite flying through this region after a storm is hit.

[00:33:22]Forced to travel through a thicker gas, satellites can be dragged out of their orbit and crashed to Earth.

[00:33:30]In 1979, even Skyab was vulnerable. The upper atmosphere Skyab was traveling [music] through was heated by a series of solar storms. Eventually, [music] it crashed uncontrollably to Earth.

[00:34:02]Now, we're not always in a position to wait for space storms to come. So, we have another instrument here on site called the heater. And we can then simulate these space weather events using the heater to heat the atmosphere at high altitudes. cause the atmosphere to expand so that we can study the atmospheric expansion and therefore the effect on satellites.

[00:34:26]Well, it's 8:00 in the evening and we've just completed running this new experiment and we have the initial results on the screen here from the radar. When you heat the atmosphere, you heat a gas, you expect it to expand. So if the gas is expanding and the atmosphere is lifting then you would expect at the altitude that a satellite normally flies that the density would be increasing and you see that very clearly over here. This is the panel that shows density. The red colors at say 500 kilometers where a satellite normally flies indicate high density and every time we turn the heater on we see that the density is increasing. Now the importance of this experiment is that we can make this measurement very precisely. So when we see a space weather storm, a space weather event coming from the sun, we can estimate the amount of energy, the amount of heat it's bringing to the earth and therefore we could make a an accurate calculation of what the density increase would be for a satellite.

[00:35:31]So if we can predict that accurately then the operator of the satellite would be able to make a correction take some action for example fire the rocket engines to compensate for the drag and therefore prevent the satellite from crashing back to the ground. That's the important point here.

[00:35:54]With such a precise level of data, Mike hopes to provide the Space Weather Prediction Center [music] with a realtime feed of atmospheric density, giving satellite companies enough information to protect their satellites.

[00:36:13]The aurora is but a faint trace of the solar wind's true strength. [music] Out there is a violent collision where it meets the Earth's magnetic field.

[00:36:28]That thin shell gives us vital shelter.

[00:36:35]It's the last night in [music] Sweden for our camera crew. It's tonight or never.

[00:36:41]>> Oh my goodness, look at those stars.

[00:36:45]It's so clear.

[00:36:52]Oh my goodness. Look at that. Look what's happening in the sky.

[00:36:59]With ordinary cameras, [music] you can see it faintly. But to capture it in its full glory, you need time-lapse cameras.

[00:37:09][music] It just gives me an absolute physical vibe and thrill. I cannot imagine ever living anywhere that I can't [music] experience the northern lights during the rest of my lifetime.

[00:37:28]It means that much to me.

[00:37:33]The aurora is a stunningly [music] beautiful display of the solar wind, but it's also a reminder that thanks to our [music] magnetic field, the majority never reaches us.

[00:37:46]>> [music] >> It's a mere hint of the vast amount of radiation and particles that the sun sends our way.

[00:38:00]During periods of high solar activity, the magnetic loops in the sun's atmosphere become tangled and knotted, and occasionally they snap.

[00:38:13]a billion tons of mass from the sun being ejected [music] into space.

[00:38:19]Such eruptions are called coronal mass ejections.

[00:38:23]These solar storms are the most high energy events in the solar system, and the sun unleashes [music] more of them at solar maximum than at any other time.

[00:38:34]The clouds of plasma they send our way travel at alarming speeds. To cover the 90 million miles from the sun, seen here reduced in [music] scale on the right to the Earth on the left can take less than a day.

[00:39:03]Solar storms can destroy satellites, silence communications, and ground aircraft.

[00:39:20]>> But the link in our modern lives it threatens most is our dependence on electricity.

[00:39:30]The highly charged particles [music] of coronal mass ejections can induce powerful electrical currents on the Earth's surface, overloading circuits, and melting transformers.

[00:39:43]This could take out lighting, heating, our ability to refrigerate and cook food, operate fuel pumps, sanitation, and water supplies.

[00:39:58]>> [music] >> We know we're vulnerable because we've been hit in the past.

[00:40:04]In Quebec, the entire power grid went down after a solar storm in 1989, plunging millions [music] into freezing darkness.

[00:40:17]But we're not helpless.

[00:40:19]Technology and systems are already being built [music] that are resilient to solar storms. And the best thing of all would be to have an early warning system.

[00:40:29]Fortunately, there is one inside [music] this building.

[00:40:34]>> Filaments and there were several filaments that >> the space weather prediction center in Colorado is the only team on the planet solely dedicated to watching [music] for solar storms.

[00:40:44]>> 24 hours. However, now in the next 3 days, no alerts or warnings. The aim is to give [music] even a few hours warning for governments, the power grid, aviation, and space industries to get ready when a storm's on its way.

[00:41:01]The forecasters have their eyes peeled for the telltale signs that a storm could be coming. Space weather really starts with with sunspots. So, if we don't have big complex sunspots, we really don't have those source regions for the big significant activity. So essentially before we get a big event, before we get that first clue that we should start looking for the other pieces, we're really looking at the sunspots. How big are they? Um how much are they changing? Uh the black and white here is if you could see magnetically, you know, how magnetically complex they are. So essentially the uh two ends of a magnet, so to speak, the white and the black. If those get very close together, uh you can get very very explosive reconnections. The next piece we start looking for on on chronograph images, for example, where we've essentially blocked out the sun and watch the outer atmosphere around that.

[00:41:48]We start to watch and see with this eruption, was there a big portion of the outer atmosphere blown into space? And if so, is it headed right at us?

[00:42:02]Every one of these amazing images is being beamed to us from the new generation of solar satellites.

[00:42:12]They are our eyes in space to keep watch over the sun.

[00:42:19]They can see the sun with visible light, magnetic fields, [music] x-rays, ultraviolet.

[00:42:38]On a typical day near solar maximum, the sun will send out three coronal mass ejections.

[00:42:45][music] Fortunately, today there haven't been any. [music] But dramatic events can happen with little warning.

[00:43:02]Violent and volatile.

[00:43:04]Our 4 1/2 billiony old sun becomes more [music] dangerous as it ages.

[00:43:10]The sun's chaotic behavior threatens technology across the planet. Weather forecasting, communication, banking, the internet, all of that would be damaged if not destroyed by a big solar storm.

[00:43:26]The warning system that we have in place now is better than nothing certainly.

[00:43:30]Um, is it enough? I would say no.

[00:43:35]But the sun offers clues that can help us predict its behavior.

[00:43:43]Pulling away the loose gases of the sun's atmosphere reveals black discs the size of a planet that drift on a layer of boiling plasma.

[00:43:59]Sunspots Slicing through them reveals they are more than skin deep.

[00:44:12]Areas of darkened plasma extend far below.

[00:44:17]Stretching thousands of miles into the sun's interior.

[00:44:24]Whenever you see these spots, you know that the magnetic field is very intense and very violent in those areas. So when you see lots of sunspots, you will also see flares and prominences and things being thrown off the sun.

[00:44:38]>> But by the time we see sunspots from Earth, we can already be under attack.

[00:44:44]How these dark patches form could be the missing link in predicting solar storms.

[00:44:51]At the University of Birmingham, Bill Chaplan is on a mission to increase solar warning times from [music] minutes to days.

[00:45:04]Bill thinks the key is not just watching the sun, but also listening to it.

[00:45:10]And just below the visible surface of the sun, then the gas is very turbulent.

[00:45:14]So there are lots of very rapid changes in pressure. The gas is whizzing everywhere. And what that does is it makes sound.

[00:45:23]And what we're doing is we're actually measuring the effects of these sound waves inside the sun.

[00:45:31]Bill's network of six observatories around the world detects the sun's surface moving back [music] and forth and records the sound this motion creates.

[00:45:44]These realtime sounds reveal what is happening below the surface.

[00:45:50]If he can identify what causes the sound waves, Bill can predict when the sunspots will occur.

[00:45:59]Bill believes the source of these sounds lies deep inside the sun where sunspots are born.

[00:46:10]40,000 m down, huge convection currents swirl the plasma in endless [music] circles.

[00:46:22]When magnetic disturbances touch the currents, the plasma cools and darkens before rising at 1300 mph, creating turbulent sound waves.

[00:46:38]2 days later, it emerges as a sunspot, a warning that a deadly eruption [music] could be just days away.

[00:46:51]For Bill, recording the sound of the sun is the easy part.

[00:46:56]Determining what the data means is the real challenge.

[00:47:01]So the sun is playing these notes all the time. But if those the notes get a little bit higher or lower, it's telling us about ways in which the conditions in the sun are changing.

[00:47:13]So if the sun were to get a bit more active, then the sound of the note might get a little bit higher.

[00:47:20]And then as the sun goes into a less active phase, when it's much quieter, [music] the sound will be lower.

[00:47:29]The goal now is to predict the sun's behavior several days in advance >> in terms of being able to predict what's happening in the future. The more we carry on listening to the sun, uh, the more we will understand about it.

[00:47:43]>> Sunspots do more than unlock the mysteries of our own star.

[00:47:47]They also highlight just how odd our solar system is compared to the rest of the cosmos.

[00:47:53]>> Evolving here on the Earth, we've developed this wonderful blind spot. We sort of look at the conditions around us and we say, "Hey, those must be the normal conditions for the rest of the universe." But in fact, there are some ways that we are substantially different from the norm. And one is that we only have one star in our solar system. Most stars in the sky live in binary star systems where there would be two stars.

[00:48:15]When you have two stars living together, evolving together, there's no reason the relationship has to be equal.

[00:48:24]There's a seriously dysfunctional relationship playing out only 90 light years from Earth.

[00:48:31]VW CFI.

[00:48:34]It's not just [music] one star, but two joined together.

[00:48:43]The smaller parasitic twin slowly feeds off the bigger one, which drives the stars magnetic fields crazy.

[00:48:55]This creates so many star spots that more than half of [music] VWCI's surface is cloaked in darkness.

[00:49:07]Our lone star system is a haven in a violent cosmos.

[00:49:15]The source of our own stars chaotic behavior comes from the most extreme [music] place in the solar system.

[00:49:23]A giant nuclear [music] reactor 10,000 times the size of Earth.

[00:49:33]The core.

[00:49:35]Could we one day harness its immense power?

[00:49:41]The sun contains over 99% of all the mass in the solar system.

[00:49:49]It produces 9 million times the United States annual energy consumption every second.

[00:49:57]The source of this enormous power lies deep inside the sun.

[00:50:12]The core 10 times denser than lead. It burns at 27 million degrees Fahrenheit and behaves like a gas.

[00:50:23]Extreme pressure fuses hydrogen atoms into helium, spitting out the energy of 100 billion tons of dynamite every second.

[00:50:37]This gigantic thermonuclear [music] warhead powers all life on our planet.

[00:50:45]When you get up in the morning and flip on a light switch, turn on your computer, get in your car and turn it on, you're using energy that was generated by the sun and has been stored here on Earth for tens or even hundreds of millions of years.

[00:51:00][music] Sunrise in the Mojave Desert.

[00:51:06]A team of engineers prepares to harvest the sun's energy with a radically new type of power plant.

[00:51:16]>> It's a solar plant, but it's not a solar [music] plant you're normally used to.

[00:51:20]It's not the panels you see on people's houses. It's different than most anything you've ever seen.

[00:51:26]>> For solar engineer [music] Stacy Browning, the sun is her most important resource.

[00:51:34]to harness the sun's rays. Stacy's team uses over 300,000 mirrors to power more than 140,000 homes.

[00:51:46]They're called the solar field.

[00:51:49]>> These don't absorb the the heat and the energy from the sun. These are mirrors.

[00:51:54]They truly reflect the sun's rays up onto this boiler. And we boil water, we make steam, and we make electricity.

[00:52:00][music] The mirrors funnel the sun's energy particles to a single point four stories high. [music] It's called a power tower.

[00:52:11]It turns water into steam at 1,000°, driving three turbines to produce electricity.

[00:52:20]Harnessing sunlight this way requires ultimate accuracy.

[00:52:26]If the mirrors miss their target, the turbines will grind to a halt.

[00:52:36]So, the accuracy of the mirrors out here in the field is one of the most important things. When all of these were put in, they were geollocated and had to be within half an inch of the planned location.

[00:52:51]>> The light hitting [music] the tower left the sun only 8 minutes earlier.

[00:52:56]But this was just the final stage in an epic journey that began a millennia ago.

[00:53:06]Before light can emerge from the surface of the sun, it must undergo an incredible transformation.

[00:53:14]It all starts deep in the heart of our star.

[00:53:21]The nuclear furnace in the core expels energy as lethal gamma radiation.

[00:53:28]Unfiltered, straight from the core, these rays would destroy life on Earth.

[00:53:34]But there's more to the sun than just the core.

[00:53:40]A layer of plasma [music] 10 times denser than rock wraps around the core.

[00:53:46]As radiation squeezes through the dense [music] body of the sun, it becomes less and less aggressive. And after 170,000 years, it finally reaches the surface, transformed into the sunlight we see.

[00:54:06]Capturing this sunlight at the solar field isn't easy.

[00:54:11]With the plant at maximum capacity, [music] Stacy discovers an issue.

[00:54:16]One of the mirrors is stopped pointing at the power tower. She heads to the [music] solar field to track down the rogue reflector.

[00:54:25]>> ID number is Hotel Echo Charlie. [music] I will put it back in its original state. Thank you.

[00:54:33]140,000 [music] homes rely on the power the field generates.

[00:54:39]>> All better.

[00:54:41]>> An average of 340 days of sunshine a year makes Stacy's plant the perfect way to harness the sun's energy.

[00:54:52]Our sun is not the only star in the cosmos with such a huge energy output.

[00:54:58]The sun is really close and so therefore it has a huge consequence for life here on Earth. It looks big compared to the other stars. But actually the sun is a really small star. There are some absolute monsters out there.

[00:55:13]One of the most extreme monsters in the galaxy lurks 250 light years away from Earth.

[00:55:21]The giant star Bellatrix.

[00:55:26]Six times bigger than our sun. It shines 4,000 times brighter with its blue fire.

[00:55:35]Inside the core is in nuclear overdrive.

[00:55:41]Bellatrix burns its fuel so fiercely it will live fast and die young.

[00:55:50]If the lifetime of our sun were a single day, Bellatrix would only live for a few minutes.

[00:56:00]Our star may be small, but its stable core means that it will continue burning steadily for 5 billion more years, but that doesn't mean it will always be a good neighbor.

[00:56:13]The sun [music] is hiding a killer menace that stretches throughout the entire solar system and threatens anyone in its path. We're completely at the mercy of our sun. We can't control it.

[00:56:25]We barely understand it. And all life depends on it.

[00:56:31]>> But has our sun turned to the dark side?

[00:56:36]>> What the heck is going on there?

[00:56:38][snorts] A giant chunk of the sun is missing.

[00:56:42]>> There was a hole. Nothing there.

[00:56:45]>> It's as if aliens had scooped the surface.

[00:56:55]>> July 2013.

[00:56:57]Gdddard Space Center, the headquarters of NASA's SOHO Solar Observatory.

[00:57:03]Its mission to keep an eye on our fiery star. The Soho Project is an early warning system about new phenomena which could have an impact here on Earth.

[00:57:14]>> Scientists monitoring the satellite feeds see something extraordinary.

[00:57:22]A gigantic shadow creeping across the sun.

[00:57:28]A 500,000m wide hole.

[00:57:33]As NASA struggles to assess the threat, the dramatic images fuel a storm of speculation.

[00:57:41]>> This was weird. We don't know whether that was artificially induced on the sun.

[00:57:46]>> It's as if aliens had scooped the surface.

[00:57:51]>> Whatever the cause, the results could be catastrophic. For us, [snorts] a dip of even [music] 7% in the sun's output could cast the Earth into another ice age.

[00:58:09]On NASA's satellite feeds, the strange black void is unmistakable.

[00:58:17]But outside, the summer sun seems to shine as brightly as ever, while the hole remains invisible to the naked eye.

[00:58:27]So, here we are on Earth living our normal lives, and there's a disaster movie going on on the sun.

[00:58:37]>> In an effort to explain the hole, scientists turn to a satellite that captures pictures of super hot gases in the sun's atmosphere.

[00:58:46]Its high-tech cameras see things that humans can't. Things [music] visible only in the ultraviolet spectrum.

[00:58:54]Suddenly, the hole looks different.

[00:58:57]>> What appears to be an area of dark, empty space. In actual fact, it's filled with gases that are much colder than those that we can see in the area around it.

[00:59:08]>> The giant shadow is really a cold patch in the sun's [music] atmosphere.

[00:59:12]>> When we're talking a cold patch, we're not talking Alaska. It's still a million degrees.

[00:59:19]>> Solar scientists call these cooler areas coronal holes.

[00:59:25]>> Coronal holes are places where material can escape and get out into the interplanetary medium.

[00:59:30]>> To the horror of scientists, this coronal hole could be in a perfect position to blast the Earth with solar particles. this giant coronal hole is spewing charged particles across space and when the earth happens to be in the way you can get a solar storm.

[00:59:57]A solar storm can knock out satellites.

[01:00:00]Electronics won't function properly and we have occasion had that happen. That's real. That's not an imaginary concern.

[01:00:13]If we got hit, it's really a big deal.

[01:00:17]>> Traveling at 1 and a [music] half million miles an hour, the deadly sunbeam will take 58 hours to reach the Earth. When it hits, the first sign should be a spectacular light show at the Aurora Borealis as the planet's [music] magneettosphere fights to protect us by absorbing the energy of the bombarding particles.

[01:00:42]July 20th, 2013, 2 and 1/2 days after scientists first spotted the hole, the northern sky erupts with flashing colors.

[01:00:53]Could this [music] be the opening act in a global meltdown?

[01:00:58]The awesome display lasts for 2 days, then dims.

[01:01:07]To the scientist's relief, the storm was nothing more than a beautiful light show.

[01:01:14]It dealt Earth a glancing blow.

[01:01:17]Next time, we might not be so lucky.

[01:01:21]The sun can have quite a temper and can turn into a real potential foe.

[01:01:30]Strange as it may seem, there's a lot we don't know about that big orange ball up there.