0:00:07 > 0:00:12Something is stirring on the face of our nearest star.
0:00:12 > 0:00:15Something powerful and unsettling.
0:00:17 > 0:00:19Because the sun is becoming more active
0:00:19 > 0:00:24it will have an impact in the lives of millions of people.
0:00:24 > 0:00:28To understand what's coming our way,
0:00:28 > 0:00:31they are doing something we cannot,
0:00:31 > 0:00:34stare directly into the sun.
0:00:34 > 0:00:36If the sun keeps carrying on like this,
0:00:36 > 0:00:39we could be in for some really big storms over the next 12 months.
0:00:43 > 0:00:45What they are expecting in the next year
0:00:45 > 0:00:50are colossal eruptions from the sun
0:00:50 > 0:00:54that fling billions of tonnes of plasma towards our planet.
0:00:57 > 0:01:02Our hi-tech society has never been so vulnerable,
0:01:02 > 0:01:04for when a solar storm strikes,...
0:01:10 > 0:01:13..it could shut us down.
0:01:17 > 0:01:20If we don't understand space weather more clearly,
0:01:20 > 0:01:23we could easily end up in the electronic dark ages.
0:01:23 > 0:01:28We are playing a game of Russian roulette with the sun.
0:01:28 > 0:01:31If we play that game long enough, we will lose.
0:01:59 > 0:02:02We all worry about the weather,...
0:02:04 > 0:02:08..but now there is a new kind of weather to worry about.
0:02:10 > 0:02:14This weather comes not from over the horizon,
0:02:14 > 0:02:17but from 93 million miles beyond it.
0:02:31 > 0:02:34'Winds blowing once again...
0:02:36 > 0:02:40'..But we still enjoy the clear sky and bright sunshine during the day
0:02:40 > 0:02:44'so we should be bright, dry and quiet in the middle and latter portion of the week.'
0:02:47 > 0:02:51Outer space is about to get a whole lot closer to home.
0:03:11 > 0:03:13The giver of life, light and heat,
0:03:13 > 0:03:17that looks so placid, is anything but.
0:03:27 > 0:03:30When violence erupts on its surface,...
0:03:37 > 0:03:41..it has the power to bring our modern life to a standstill.
0:03:46 > 0:03:50This power was demonstrated to the world in 1989.
0:03:50 > 0:03:53The target, Quebec.
0:03:53 > 0:03:58Well, in 1989, there was a storm where we saw for real
0:03:58 > 0:04:01how serious these problems could be.
0:04:01 > 0:04:03What happened was the solar storm
0:04:03 > 0:04:05changed the magnetic field of the Earth.
0:04:05 > 0:04:08This caused currents to be induced in the ground,
0:04:08 > 0:04:11and those currents overloaded a power station.
0:04:14 > 0:04:16'There has been a big power failure in Quebec.
0:04:16 > 0:04:20'Most of the province is in darkness, including much of Montreal.'
0:04:20 > 0:04:23They went from normal operating conditions
0:04:23 > 0:04:30to complete province-wide blackout in an elapse time of 92 seconds.
0:04:31 > 0:04:35'It's so strange to see a major city like Montreal in darkness.'
0:04:35 > 0:04:39'This morning, 6 million Quebecers woke up cold and in the dark.'
0:04:39 > 0:04:42'..speculating it could have been caused by solar storms.'
0:04:46 > 0:04:49And the power was shut down for nine hours.
0:04:52 > 0:04:55This was a wake-up call for scientists.
0:05:07 > 0:05:11The secret to understanding this violent weather from space
0:05:11 > 0:05:16is a mysterious phenomenon that has bewitched scientists for centuries.
0:05:21 > 0:05:23The Arizona desert.
0:05:27 > 0:05:30Matt Penn spends more time than most
0:05:30 > 0:05:33thinking about space weather's starting point.
0:05:42 > 0:05:45Wonder if there are any up there today.
0:05:49 > 0:05:51The birthplace of space weather.
0:05:56 > 0:05:58Sunspots!
0:06:01 > 0:06:03I mean, they're a mystery, right?
0:06:03 > 0:06:05We've seen them in records from Chinese astronomers dating
0:06:05 > 0:06:08thousands of years back into history.
0:06:08 > 0:06:11But the details of how you form a sunspot are still a mystery
0:06:11 > 0:06:15and understanding that is really intriguing to me and fascinating.
0:06:15 > 0:06:18Now a sunspot itself is actually a bright object.
0:06:18 > 0:06:20If you took a sunspot off of the sun and put it into the night-time sky,
0:06:20 > 0:06:23it would be brighter than the full moon,
0:06:23 > 0:06:25but compared to the rest of the solar disc,
0:06:25 > 0:06:28it's cooler and darker and that is why it appears as a black spot.
0:06:31 > 0:06:36But to really understand how sunspots trigger solar storms,
0:06:36 > 0:06:40you need something rather more impressive
0:06:40 > 0:06:42than a piece of smoked glass.
0:07:32 > 0:07:34So we are at the prime focus of our solar telescope now.
0:07:34 > 0:07:37And what we see is a white light image of a disc of the sun.
0:07:37 > 0:07:41On the disc today we see several active regions, several sunspots.
0:07:41 > 0:07:45Each active region is perhaps five or ten times the size of Planet Earth.
0:07:45 > 0:07:47So that's a huge sunspot that we have here.
0:07:47 > 0:07:49Absolutely massive.
0:07:49 > 0:07:51Were you able to measure the magnetic field...
0:07:51 > 0:07:56The reason Matt and his team study these beautiful shapes so carefully
0:07:56 > 0:08:02is because hidden within sunspots is a unsettling truth.
0:08:02 > 0:08:05Sunspots can cause the biggest and most damaging space storms,
0:08:05 > 0:08:07solar storms, that occur.
0:08:13 > 0:08:17They follow sunspots as they travel across the face of the sun...
0:08:17 > 0:08:18That's bigger than the Earth there, right?
0:08:18 > 0:08:23It's eight, nine times the diameter of Earth, so it's a massive region.
0:08:23 > 0:08:26..just waiting for them to explode.
0:08:26 > 0:08:28That's a huge storm coming in.
0:08:28 > 0:08:29It is.
0:08:29 > 0:08:33It's like looking down the barrel of a loaded gun.
0:08:35 > 0:08:39Sunspots are kind of like thunderstorms on Earth.
0:08:40 > 0:08:44A big sunspot can cause a big storm, just like a big thunderhead
0:08:44 > 0:08:46can cause a big tornado on the Earth.
0:08:46 > 0:08:49Now we can't exactly predict when tornadoes will occur
0:08:49 > 0:08:52and which thunderstorms will produce tornadoes, just like on the sun
0:08:52 > 0:08:56we can't predict exactly which sunspots will spawn solar storms,
0:08:56 > 0:08:59but that's one of the main focuses of our research.
0:09:00 > 0:09:02So why is it that some sunspots
0:09:02 > 0:09:06just pass calmly across the sun's surface,
0:09:06 > 0:09:08while others erupt?
0:09:19 > 0:09:24Professor Cary Forest is at the forefront of the effort to find out.
0:09:25 > 0:09:29He's exploring the hidden world of chaos and violence
0:09:29 > 0:09:32inside our nearest star.
0:09:37 > 0:09:41The force that makes sunspots erupt is something invisible,...
0:09:47 > 0:09:51..a part of everyday life that few of us even think about.
0:10:01 > 0:10:04But it is a force so powerful,
0:10:04 > 0:10:08it can trash billions of pounds' worth of modern technology
0:10:08 > 0:10:10in a split second,...
0:10:13 > 0:10:16..bringing our modern world crashing around our ears.
0:10:18 > 0:10:21So what is this mysterious force?
0:10:23 > 0:10:25It's this!
0:10:33 > 0:10:36The same force of magnetism that's lifting this washer,
0:10:36 > 0:10:39when scaled up to solar scales, becomes strong enough
0:10:39 > 0:10:42to cause the storms that fly off the surface of the sun.
0:10:47 > 0:10:51But how these explosive levels of magnetism are created
0:10:51 > 0:10:55inside our nearest star is an urgent question for scientists.
0:11:01 > 0:11:05Cary and his team have built a daring experiment
0:11:05 > 0:11:08to study a star inside this building.
0:11:23 > 0:11:28So when we began this business, we built this crazy-looking device
0:11:28 > 0:11:31to figure out where space weather comes from.
0:11:33 > 0:11:37Inside it, they will generate the dynamics of a star.
0:11:38 > 0:11:41If you want to understand space weather,
0:11:41 > 0:11:43ultimately you have to understand the engine
0:11:43 > 0:11:47that creates some very intense powerful magnetic fields
0:11:47 > 0:11:50from a complex flow, a turbulent flow,
0:11:50 > 0:11:52of plasma inside the sun.
0:11:54 > 0:11:59This superheated plasma churns ceaselessly as the sun rotates.
0:12:03 > 0:12:07We have this device which is supposed to mimic those processes
0:12:07 > 0:12:08here on Earth.
0:12:10 > 0:12:13But this is a dangerous experiment.
0:12:13 > 0:12:16They need to fill it with an explosive element.
0:12:18 > 0:12:23So here we have a pressure vessel that holds inside of it
0:12:23 > 0:12:25flowing liquid sodium,
0:12:25 > 0:12:29which is a very dangerous, complex liquid to work with.
0:12:29 > 0:12:32Let me show you the inside.
0:12:32 > 0:12:34Watch your fingers.
0:12:37 > 0:12:39All right, that's great.
0:12:39 > 0:12:43So looking inside here you can see we have these two propellers -
0:12:43 > 0:12:47one spins this direction, the other spins in the opposite direction,
0:12:47 > 0:12:51and we create these flows that are out along the poles
0:12:51 > 0:12:54and are spinning in opposite directions
0:12:54 > 0:12:57and it's those flows which can take very small magnetic fields
0:12:57 > 0:13:01and can amplify them up into big loops of magnetic field,
0:13:01 > 0:13:03that ultimately bubble out
0:13:03 > 0:13:06and emerge from the surface of the sphere,
0:13:06 > 0:13:10and would basically be the same sort of process that happens on the sun.
0:13:10 > 0:13:13He's hoping to generate these.
0:13:21 > 0:13:23OK, guys, let's fill the experiment.
0:13:33 > 0:13:35This is the experiment.
0:13:35 > 0:13:38It is exactly the same as the experiment I showed you earlier,
0:13:38 > 0:13:40except it's covered with insulation,
0:13:40 > 0:13:43we have it at very high temperature,
0:13:43 > 0:13:47these pipes coming in bring hot oil to the surface of the experiment,
0:13:47 > 0:13:51to keep it at the 100 degrees Celsius at which sodium melts,
0:13:51 > 0:13:56and then all of the wires going in go to magnetic field sensors
0:13:56 > 0:13:59that measure the magnetic field that comes out of the vessel.
0:14:02 > 0:14:07Now they have to pump 300 gallons from an underground storage tank
0:14:07 > 0:14:09into their sphere.
0:14:18 > 0:14:20There are many steps to that
0:14:20 > 0:14:23and many places for things to go wrong, so we're completely on edge
0:14:23 > 0:14:26as we are trying to get the sodium up into the vessel.
0:14:26 > 0:14:28Check the temperature of the transfer line.
0:14:28 > 0:14:32There's enough potential chemical energy in this volume of sodium
0:14:32 > 0:14:35to blow this building to smithereens.
0:14:35 > 0:14:39Reset the offset of the amplifiers and then we're good to go.
0:14:39 > 0:14:42When we do the experiment itself, we're going to leave this room
0:14:42 > 0:14:45go to the remote control room and do the experiments
0:14:45 > 0:14:47from outside the room so we're completely safe.
0:14:50 > 0:14:52- Can we go ahead and turn things on here?- Yeah.- Yep.
0:15:00 > 0:15:03Right now we're at 100rpm and what you see here
0:15:03 > 0:15:05is a very weak magnetic field
0:15:05 > 0:15:08generated deep inside the experiment.
0:15:08 > 0:15:13At low speeds, this experiment creates a magnetic field
0:15:13 > 0:15:15a bit like the Earth's.
0:15:15 > 0:15:20But as you increase the speed, the dynamics of the experiment change.
0:15:20 > 0:15:24At maximum speed, it starts behaving like a star.
0:15:26 > 0:15:28We're going to change the motor speed
0:15:28 > 0:15:32and really increase the drive of the generator
0:15:32 > 0:15:35and so the next thing here is to...
0:15:35 > 0:15:39is to look and see what changes when we make that change in speed.
0:15:39 > 0:15:40We're going up to 1400 rpm.
0:15:43 > 0:15:46We're really pushing the limit of the experiment here - it gets hot,
0:15:46 > 0:15:48the power levels are high,
0:15:48 > 0:15:51it's about as fast as the propellers can go.
0:15:53 > 0:15:56And we are there.
0:15:56 > 0:15:59- Wow!- We're up to speed. - This is amazing.
0:15:59 > 0:16:04So, you can see, the turbulence levels are coming way up...
0:16:04 > 0:16:06Cary's discovered magnetic power
0:16:06 > 0:16:09doesn't just rise gently with motor speed,
0:16:09 > 0:16:12it takes a massive leap.
0:16:12 > 0:16:15These are flux loops that are popping out of the surface of the sphere.
0:16:15 > 0:16:17They're very noisy, very chaotic,
0:16:17 > 0:16:19much like the surface of the sun would be.
0:16:25 > 0:16:30This gives you a sense of what's happening inside our nearest star,
0:16:30 > 0:16:33the process that gives space weather its teeth.
0:16:41 > 0:16:45So just imagine what would happen if we took this experiment,
0:16:45 > 0:16:47which is really small,
0:16:47 > 0:16:51and we increased its size to something like the surface of the sun
0:16:51 > 0:16:55and we increased its engine to the power of the thermonuclear engine
0:16:55 > 0:16:58of the core of the sun and what would be generated.
0:16:58 > 0:17:03Those are really astronomically big numbers that we'd be talking about.
0:17:03 > 0:17:06The power that can be generated in the magnetic field
0:17:06 > 0:17:09on the surface of the sun is really enormous
0:17:09 > 0:17:12and you can really see why space weather is really a scary thing.
0:17:17 > 0:17:21Ultimately, this magnetic energy has to find a way out.
0:17:22 > 0:17:26Sunspots are one way that twisted magnetic energy
0:17:26 > 0:17:28finds its way to the surface of the sun.
0:17:30 > 0:17:33But why do some sunspots then explode,
0:17:33 > 0:17:37releasing a storm that can threaten our way of life?
0:17:50 > 0:17:54The team at Tucson are measuring sunspots
0:17:54 > 0:17:58to investigate the moment one goes critical.
0:17:59 > 0:18:02- You look for the lowest intensity on the meter here.- Exactly.
0:18:02 > 0:18:04So you can see we're raising in intensity here.
0:18:04 > 0:18:07They examine infrared light from the telescope
0:18:07 > 0:18:10to try and understand when the twisting of the magnetic field
0:18:10 > 0:18:13could create a solar eruption.
0:18:13 > 0:18:17So that's a big sunspot, Bill. It might produce some solar storms.
0:18:17 > 0:18:19- The one to watch.- Right.
0:18:19 > 0:18:22Yeah, that's the most complicated active region.
0:18:22 > 0:18:24And the structure here is...
0:18:24 > 0:18:27Looks like it's changing with time.
0:18:27 > 0:18:31- Right.- Which can produce a stress on the system.- Right.
0:18:31 > 0:18:35It can store energy on the magnetic field and then erupt as a storm.
0:18:35 > 0:18:38As the sunspots evolve on the surface of the sun,
0:18:38 > 0:18:41flows and other gas dynamics
0:18:41 > 0:18:44can cause the sunspots to twist up their magnetic field.
0:18:44 > 0:18:47And if this continues for a long period of time,
0:18:47 > 0:18:50a twisted magnetic field can store energy,
0:18:50 > 0:18:52just like a twisted rubber band can store energy,
0:18:52 > 0:18:56and just like a rubber band, when the magnetic field becomes too twisted,
0:18:56 > 0:18:58it can snap.
0:19:03 > 0:19:08It is this snap that ultimately propels a solar storm
0:19:08 > 0:19:12from the sun's surface and sends it hurtling towards the Earth.
0:19:16 > 0:19:19But this on its own does not explain solar storms.
0:19:21 > 0:19:25Something else has to happen on the sun.
0:19:25 > 0:19:27Something has to pull the trigger.
0:19:36 > 0:19:39Paul Bellan reckons he might know what it is.
0:19:41 > 0:19:43That's because he's in charge
0:19:43 > 0:19:46of a highly sophisticated piece of equipment.
0:20:06 > 0:20:10What we believe is that just as I'm blowing bubbles,
0:20:10 > 0:20:14the sun is blowing magnetic bubbles off of its surface.
0:20:14 > 0:20:17When I blow a bubble, if I blow it just a little bit,
0:20:17 > 0:20:21it expands but it doesn't break off,
0:20:21 > 0:20:25but if I blow it harder, it breaks off and forms a bubble.
0:20:26 > 0:20:28The same with the sun,
0:20:28 > 0:20:31if the magnetic fields on the sun blow a little bit,
0:20:31 > 0:20:34the structures stretch out but they don't break off.
0:20:34 > 0:20:36However, if the sun blows a lot,
0:20:36 > 0:20:39with its magnetic field, then a structure breaks off,
0:20:39 > 0:20:44and this bubble of plasma and magnetic field
0:20:44 > 0:20:45can fly towards the Earth.
0:20:54 > 0:20:58To understand what makes the plasma break off,
0:20:58 > 0:21:00Paul has built a machine
0:21:00 > 0:21:04which can do something that sounds impossible -
0:21:04 > 0:21:07create a mini solar storm right here on Earth.
0:21:09 > 0:21:13To do that, they must create a piece of the sun's surface
0:21:13 > 0:21:15inside this chamber.
0:21:15 > 0:21:21Massive electric currents supply the magnetic field through this rod,
0:21:21 > 0:21:25generating a cloud of plasma just like the surface of the sun.
0:21:28 > 0:21:30These conditions only last a split second,
0:21:30 > 0:21:34and have to be imaged by this high-speed camera
0:21:34 > 0:21:37that captures the moment of eruption.
0:21:44 > 0:21:47- Are you ready to turn on the high voltage?- Yep.
0:21:47 > 0:21:49- OK, let's go for four kilovolts.- OK.
0:21:49 > 0:21:51Charging.
0:21:52 > 0:21:54One kilovolt,
0:21:54 > 0:21:57one and a half,
0:21:57 > 0:22:00two, two and a half,
0:22:00 > 0:22:02three,
0:22:02 > 0:22:03three and a half,
0:22:03 > 0:22:06four.
0:22:10 > 0:22:12Well, we've got a nice shot here.
0:22:12 > 0:22:16This is a plasma loop with very large currents and magnetic fields.
0:22:16 > 0:22:20It's exploding outwards at very high velocity,
0:22:20 > 0:22:22tens of kilometres per second.
0:22:22 > 0:22:25The electric currents here are very large,
0:22:25 > 0:22:29the electric power that we're using of the order of a 100 million watts,
0:22:29 > 0:22:32the sort of power you would use for running a small city.
0:22:32 > 0:22:37So here we have an electric current of probably about 50,000 amps
0:22:37 > 0:22:39going from a top electrode to a bottom electrode.
0:22:39 > 0:22:41That produces a magnetic force
0:22:41 > 0:22:44that effectively is producing a pressure inside
0:22:44 > 0:22:47that's pushing this plasma out,
0:22:47 > 0:22:50just like the air pressure on the bubble pushes the bubble out.
0:22:51 > 0:22:55Just like a bubble, these loops on the sun need to re-connect.
0:23:05 > 0:23:08And when it gets pushed out to a certain point, it can break off.
0:23:08 > 0:23:11That's magnetic re-connection - it's like the bubble popping
0:23:11 > 0:23:15and the popping here isn't a pop like the sound you hear,
0:23:15 > 0:23:17it's actually X-rays being shot out
0:23:17 > 0:23:19and energetic particles being shot out.
0:23:24 > 0:23:26So what you get is energetic particles, X-rays,
0:23:26 > 0:23:29and the actual plasma can head towards Earth.
0:23:29 > 0:23:33Plasma can plough into the Earth and wreak havoc.
0:23:40 > 0:23:44So this is how a solar storm comes our way,
0:23:44 > 0:23:48one with the power to black out a city in seconds.
0:23:49 > 0:23:53First, the awesome magnetic power of the sun
0:23:53 > 0:23:57is twisted into a threatening sunspot.
0:24:01 > 0:24:06Then, this twisting hurls field lines out into space.
0:24:06 > 0:24:08But they are still anchored.
0:24:12 > 0:24:17Finally, some get dangerously close and then they reconnect.
0:24:24 > 0:24:28A solar flare explodes in a flash of visible light,
0:24:28 > 0:24:32energetic particles and X-rays.
0:24:32 > 0:24:37It is the power of a billion atom bombs exploding all at once.
0:24:42 > 0:24:44But there's more.
0:24:44 > 0:24:51A nanosecond later, a coronal mass ejection, or CME, erupts.
0:24:57 > 0:25:00Billions of tonnes of the sun hurled into space.
0:25:08 > 0:25:12This is the sun's plasma wrapped in a magnetic field.
0:25:15 > 0:25:21Not surprisingly, scientists want to know when the next one is coming.
0:25:30 > 0:25:32'..tomorrow we'll hang on to the sun,
0:25:32 > 0:25:34'but temperatures don't move much at all.
0:25:34 > 0:25:37'We're going to climb to the mid-50s Tuesday,
0:25:37 > 0:25:39'with lots of sunshine in the forecast Wednesday.
0:25:39 > 0:25:42'That's when temperatures are going to start to creep up, but still...'
0:25:44 > 0:25:47I don't usually listen to the weather
0:25:47 > 0:25:50so sometimes I wake up to maybe a bit of a surprise.
0:25:53 > 0:25:56This is Bob.
0:25:56 > 0:25:58Bob is a weatherman.
0:26:00 > 0:26:03But he couldn't care less if it is about to snow.
0:26:06 > 0:26:10- Morning, guys.- Morning, Bob. - How's it going?- Ready to take over?
0:26:10 > 0:26:12- Pretty quiet night?- Pretty quiet.
0:26:12 > 0:26:14Numerous CMEs, in fact, that are...
0:26:14 > 0:26:16Right now you can just see this one right here,
0:26:16 > 0:26:19filling an eruption along this channel here,
0:26:19 > 0:26:22generated this large CME.
0:26:22 > 0:26:24Looks pretty far south of the ecliptic
0:26:24 > 0:26:27so it doesn't appear to be Earth directed.
0:26:27 > 0:26:31Plenty happening overnight but nothing coming our way.
0:26:31 > 0:26:33Another close shave for Planet Earth.
0:26:33 > 0:26:37Other than that, we're doing good.
0:26:37 > 0:26:41Here at the Space Weather Prediction Centre in Boulder, Colorado,
0:26:41 > 0:26:47Bob and his team are the first line of defence for the entire planet.
0:26:47 > 0:26:48Running a zero-three over here.
0:26:48 > 0:26:53They provide forecasts to airlines, power and satellite companies,
0:26:53 > 0:26:57all vital services that need protection from solar storms.
0:26:57 > 0:27:00No space weather storms were observed for the past 24 hours,
0:27:00 > 0:27:04no space weather storms are predicted for the next 24 hours.
0:27:04 > 0:27:09A wealth of data is fed here, live, to the control room, 24/7.
0:27:09 > 0:27:12Just on the edge so we can still get some of the X-rays.
0:27:12 > 0:27:16They can monitor our nearest star in real time,
0:27:16 > 0:27:19in almost every conceivable wavelength of light.
0:27:21 > 0:27:25But all these hi-tech marvels are vital
0:27:25 > 0:27:27when you consider what is at stake.
0:27:27 > 0:27:30There's billions of dollars' worth of satellites up there.
0:27:30 > 0:27:33Our critical infrastructure, such as the power grid,
0:27:33 > 0:27:34relies on the things we do.
0:27:34 > 0:27:37If you turn off power, all kinds of things go wrong.
0:27:40 > 0:27:44And if things do go wrong, our first warning comes from here.
0:27:46 > 0:27:49The ACE satellite,
0:27:49 > 0:27:53floating 1.1 million miles from Earth.
0:27:53 > 0:27:57It has been protecting our planet since 1997.
0:27:59 > 0:28:04Once a storm hits ACE, it will hit Earth less than an hour later.
0:28:04 > 0:28:06It's nail-biting stuff.
0:28:07 > 0:28:10It's our little beacon in space.
0:28:11 > 0:28:14Any storm that's coming from the sun is going to hit the Earth,
0:28:14 > 0:28:16and has to pass over ACE.
0:28:16 > 0:28:18That gives us, in worst case,
0:28:18 > 0:28:22only 15 minutes before that CME slams into the Earth.
0:28:22 > 0:28:25But that's about it. Once it hits ACE we've got, at most,
0:28:25 > 0:28:29an hour's warning before that storm is going to begin on Earth.
0:28:30 > 0:28:36This control room was put to the test in October of 2003.
0:28:46 > 0:28:50The 2003 Halloween storms were really a series of significant space weather events.
0:28:50 > 0:28:52There wasn't just one big region, there were three of them.
0:28:52 > 0:28:57And they were popping off large flares and fast CMEs all the time.
0:28:57 > 0:29:00And initially, the CMEs were missing the Earth
0:29:00 > 0:29:03and we were just getting the effects of the flares.
0:29:03 > 0:29:04The solar flare itself is light,
0:29:04 > 0:29:06so it's getting from sun to Earth in eight minutes.
0:29:06 > 0:29:09As soon as we're measuring it with our satellites, it's here.
0:29:11 > 0:29:14As the regions marched towards disc centre,
0:29:14 > 0:29:15we had to worry more and more
0:29:15 > 0:29:18about coronal mass ejections hitting the Earth.
0:29:18 > 0:29:20We really had, kind of, the perfect storm
0:29:20 > 0:29:22of all of the big phenomena associated with space weather.
0:29:28 > 0:29:31But this was just the beginning.
0:29:31 > 0:29:33The next day, Tuesday October 28th,
0:29:33 > 0:29:37began much like any other on Planet Earth.
0:29:37 > 0:29:43Then, at 11.12am, Planet Earth came under attack.
0:29:43 > 0:29:49October 28th was to me the key date
0:29:49 > 0:29:53because we had a huge X10 solar flare
0:29:53 > 0:29:55that erupted with a coronal mass ejection,
0:29:55 > 0:29:58travelling faster than 2,000 kilometres per second.
0:30:00 > 0:30:02X class is the biggest flare you get.
0:30:04 > 0:30:06Here you can see what happens
0:30:06 > 0:30:09when the flare hits the space telescope camera.
0:30:12 > 0:30:14'It may sound like the plot of a science-fiction movie,
0:30:14 > 0:30:18'but the Earth is currently under attack from the sun.'
0:30:18 > 0:30:21'A mass of material hurtling towards the Earth
0:30:21 > 0:30:24'at five million miles an hour.'
0:30:25 > 0:30:27We knew it was going to get here fast.
0:30:27 > 0:30:30In fact, it got to the Earth in 19 hours.
0:30:30 > 0:30:32That's almost the fastest on record.
0:30:32 > 0:30:35The problem with that was,
0:30:35 > 0:30:39such a fast event drives large populations of energetic protons.
0:30:39 > 0:30:43Those protons blind part of the ACE satellite data.
0:30:43 > 0:30:46It's too close. The spacecraft is right in front of the sun
0:30:46 > 0:30:48so we can't see it.
0:30:48 > 0:30:51We had a satellite looking at the sun but it's blinded by the sun.
0:30:51 > 0:30:53That happens.
0:31:06 > 0:31:09The ACE satellite hung on long enough,
0:31:09 > 0:31:11despite serious proton damage,
0:31:11 > 0:31:15to keep sending the magnetic field polarity of the storm.
0:31:17 > 0:31:20Now there's two things we're looking for in the magnetic field -
0:31:20 > 0:31:23the total intensity, cos that tells us how big the storm could be,
0:31:23 > 0:31:25but the other thing that's important
0:31:25 > 0:31:27is the direction of the magnetic field.
0:31:27 > 0:31:29Is it up and northward or is it down and southward?
0:31:29 > 0:31:33When it's up and northward it's going to be a big storm.
0:31:33 > 0:31:36When it's down and southward it's going to be a monster storm.
0:31:37 > 0:31:40That's because the Earth's magnetic field
0:31:40 > 0:31:44naturally repels storms that have a northward polarity.
0:31:45 > 0:31:48But when the polarity is southward,
0:31:48 > 0:31:52it allows the storm through the open gate of the Earth's magnetic field.
0:32:03 > 0:32:06And in October 2003,
0:32:06 > 0:32:10ACE was telling them the door was wide open.
0:32:12 > 0:32:17Early on the 29th, the CME slammed into the Earth,
0:32:17 > 0:32:20driving a G5 geomagnetic storm,
0:32:20 > 0:32:23the biggest on the scale that we measure these storms on.
0:32:24 > 0:32:27Power grid in Sweden went down,
0:32:27 > 0:32:31there were problems with the power grid in Africa.
0:32:31 > 0:32:33In the US,
0:32:33 > 0:32:37GPS systems that helped airlines get more accurate readings
0:32:37 > 0:32:41became less reliable and they had to change the operating procedures.
0:32:45 > 0:32:47Airlines were prohibited from making flight alterations
0:32:47 > 0:32:49or flying above certain latitudes.
0:32:49 > 0:32:54The power grids around the globe responded.
0:32:56 > 0:32:58This was a monster storm.
0:32:58 > 0:33:02This was one of the worst storms of recent years.
0:33:08 > 0:33:12Around the world, the people who keep the lights on
0:33:12 > 0:33:14are now on high alert.
0:33:14 > 0:33:17But they are battling a powerful foe.
0:33:17 > 0:33:20The UK's National Grid is no exception.
0:33:27 > 0:33:30Could this cause a power cut in England?
0:33:30 > 0:33:33It could, because the sun is so vast
0:33:33 > 0:33:36that we can never entirely protect against it.
0:33:38 > 0:33:42If it hits the Earth as it goes round on its orbit,
0:33:42 > 0:33:45a huge magnetic shock gets delivered to the Earth
0:33:45 > 0:33:49and that causes currents to flow along our conductors,
0:33:51 > 0:33:54down these lines here,
0:33:54 > 0:33:57right down into the core of the transformer below us.
0:33:57 > 0:34:01It can set fire to the insulating material
0:34:01 > 0:34:04that is there to protect the device.
0:34:04 > 0:34:07And when that happens we get catastrophic failure,
0:34:07 > 0:34:10and a machine like this has to get replaced.
0:34:15 > 0:34:20The National Grid, though, have developed a way to protect us.
0:34:20 > 0:34:23It turns out that the best thing to do to keep the lights on
0:34:23 > 0:34:26is the last thing you'd expect.
0:34:27 > 0:34:32Mad as it sounds, we turn every single bit of our kit on.
0:34:33 > 0:34:38That means that lines that have previously been out
0:34:38 > 0:34:40because they weren't needed
0:34:40 > 0:34:43or because people were working on them temporarily,
0:34:43 > 0:34:46we cease all work, we bring the lines back in,
0:34:46 > 0:34:49and what happens is that the currents
0:34:49 > 0:34:52induced by the coronal mass ejection hitting the Earth,
0:34:52 > 0:34:55spread out along all these different routes that it can follow
0:34:55 > 0:34:58and that reduces the amount at any one point,
0:34:58 > 0:35:02where the induced current is trying to get back down to the Earth again.
0:35:02 > 0:35:04And that protects our transformers,
0:35:04 > 0:35:08it means there's much less risk of them overheating
0:35:08 > 0:35:10and we ride out the storm that way
0:35:10 > 0:35:12and ensure that we prevent a blackout.
0:35:14 > 0:35:17It's like in a storm when you've got a huge amount of flood water
0:35:17 > 0:35:21rushing down and we turn on extra storm drains just to
0:35:21 > 0:35:24drain the power of this surge away.
0:35:29 > 0:35:34These electromagnetic storm drains may soon be put to the test.
0:35:45 > 0:35:48During the next two years, we expect the number of sunspots
0:35:48 > 0:35:51visible on the disc of the sun will reach a maximum.
0:35:51 > 0:35:53Now that's interesting because we know that
0:35:53 > 0:35:57sunspots are the source of a lot of space weather, solar storms,
0:35:57 > 0:36:00so we expect a larger number of solar storms here at the Earth.
0:36:02 > 0:36:04The reason this is important to understand is because
0:36:04 > 0:36:06it can impact our daily lives,
0:36:06 > 0:36:10either through our power system or through our communication system,
0:36:10 > 0:36:12or through our navigation system,
0:36:12 > 0:36:16and we expect to have more disruptions in our daily lives
0:36:16 > 0:36:19in the next two years because of the solar activity.
0:36:21 > 0:36:25Over the next two years, we're likely to see more storms.
0:36:28 > 0:36:30But there's one problem that takes you to the heart
0:36:30 > 0:36:32of cutting-edge solar storm research.
0:36:42 > 0:36:45Why is it that some storms hurtle from the sun
0:36:45 > 0:36:47so much faster than others?
0:37:09 > 0:37:14Scott McIntosh believes he might have the answer.
0:37:14 > 0:37:16And it all comes from a completely new and revealing
0:37:16 > 0:37:19set of images of the sun,
0:37:19 > 0:37:23taken by the state-of-the-art SDO satellite.
0:37:36 > 0:37:38It is a brand new camera in space,
0:37:38 > 0:37:41taking a high-resolution image of the sun
0:37:41 > 0:37:45in ten different wavelengths of light, once every ten seconds.
0:37:57 > 0:38:00It's the content in those images,
0:38:00 > 0:38:03and the frequency of them, how often they happen,
0:38:03 > 0:38:07that's really going to help us push through and understand better
0:38:07 > 0:38:08space weather storms.
0:38:11 > 0:38:16In these precious new images, Scott has noticed something.
0:38:16 > 0:38:19It may provide the answer why some storms
0:38:19 > 0:38:22are so much faster than others.
0:38:22 > 0:38:27He's been focusing his attention here, the sun's superheated corona.
0:38:27 > 0:38:29This is the area of the sun's atmosphere
0:38:29 > 0:38:3220 times hotter than its surface.
0:38:37 > 0:38:41This superheated layer holds in all the loops of magnetic power
0:38:41 > 0:38:45and all the hot plasma that goes to make up our nearest star.
0:38:48 > 0:38:52So you see here, the corona in super slow mo.
0:38:54 > 0:38:56And what we're looking at is that detailed evolution
0:38:56 > 0:38:58of all these coronal loops.
0:38:58 > 0:39:02These are fibres, magnetic fibres, that make up the whole corona.
0:39:02 > 0:39:04The corona is like a pressure cooker.
0:39:04 > 0:39:07And these loops are like the top of the pressure cooker.
0:39:09 > 0:39:15So watch, this is a coronal mass ejection in action back at the sun.
0:39:15 > 0:39:17If you watch really closely... Boom! You see that?
0:39:19 > 0:39:22As the material rips away, you get these two very dark patches
0:39:22 > 0:39:26either side of the active region, and watch again, boom!
0:39:26 > 0:39:29You see them. The corona gets instantaneously dark.
0:39:29 > 0:39:31Over hundreds of thousands of kilometres.
0:39:31 > 0:39:34And then it slowly patches in.
0:39:34 > 0:39:37These, as we call them, transient coronal holes,
0:39:37 > 0:39:42may provide a clue for the energy source for these superfast CMEs.
0:39:43 > 0:39:48These transient coronal holes, virtually invisible until 2010,
0:39:48 > 0:39:53are part of a mechanism that can super-charge a CME,
0:39:53 > 0:39:57ripping a hole in the corona, tapping into the sun's energy
0:39:57 > 0:39:59back down on the surface.
0:39:59 > 0:40:04If you watch closely, the coronal loops that just happened to be there
0:40:04 > 0:40:08before the corona erupted, just disappear.
0:40:08 > 0:40:10In fact they don't just disappear,
0:40:10 > 0:40:14it seems like you rip into the lower part of the atmosphere.
0:40:14 > 0:40:18All that energy that was keeping the corona at a million degrees
0:40:18 > 0:40:22now has an avenue to escape. You've basically opened the gates of hell.
0:40:26 > 0:40:29These gates are at the heart of space weather.
0:40:30 > 0:40:33Through them all the power of the sun,
0:40:33 > 0:40:37this massive reservoir of energy, has a channel to escape.
0:40:47 > 0:40:50So it's this tapping in of this reservoir of energy,
0:40:50 > 0:40:54this boundless amount of energy, that may give the CME its kick.
0:40:54 > 0:40:57The thing that gives the CME its kick to 1,000 kilometres a second,
0:40:57 > 0:41:00that lets it get to Earth that little bit faster
0:41:00 > 0:41:03than we can currently understand.
0:41:03 > 0:41:07Scott hopes to use these weird dark patches
0:41:07 > 0:41:10as a way of answering the billion-dollar question -
0:41:10 > 0:41:14is this storm hitting today or tomorrow?
0:41:15 > 0:41:18Understanding the amount of energy contained in one of these things,
0:41:18 > 0:41:22and in these transient coronal holes, will ultimately improve our ability
0:41:22 > 0:41:25to forecast their arrival time at Earth.
0:41:31 > 0:41:35An extra day's warning is of course helpful
0:41:35 > 0:41:37but the challenge is to go further,
0:41:37 > 0:41:39to give a week's warning.
0:41:41 > 0:41:45To do that, you need to do something else.
0:41:45 > 0:41:47Something that sounds a little bit unlikely.
0:41:49 > 0:41:51Listen to the sun.
0:42:16 > 0:42:19And that is what Stathis Ilonidis is doing.
0:42:29 > 0:42:33If we only use light to study the sun
0:42:33 > 0:42:38then we can only observe the surface or higher,
0:42:38 > 0:42:41but with sound, the sun is transparent, in sound.
0:42:41 > 0:42:45We can use sound to learn more about the interior of the sun.
0:42:46 > 0:42:49The turbulence of the plasma inside the sun
0:42:49 > 0:42:51means it is constantly vibrating.
0:42:52 > 0:42:55These vibrations makes sound waves
0:42:55 > 0:42:57that travel through the sun's interior.
0:42:57 > 0:43:00Here, they are sped up so we can hear them.
0:43:01 > 0:43:04This is the sound of the sun.
0:43:05 > 0:43:10By using this sound, he has tracked the positions of sunspot regions
0:43:10 > 0:43:14thousands of kilometres beneath the sun's surface.
0:43:19 > 0:43:22This is the surface of the sun.
0:43:22 > 0:43:26Here is where we observe the solar vibrations.
0:43:26 > 0:43:29We select a pair of points on the solar surface
0:43:29 > 0:43:33with a specific distance of 150,000 kilometres.
0:43:35 > 0:43:41Acoustic waves originating at one of these two locations
0:43:41 > 0:43:45will propagate down up to a depth of 60,000 km
0:43:45 > 0:43:47and they will return back to the surface
0:43:47 > 0:43:50close to the location of this point.
0:43:54 > 0:43:56Sunspots are born deep inside the sun.
0:43:56 > 0:43:59They then travel to the sun's surface
0:43:59 > 0:44:02and trigger space weather storms.
0:44:02 > 0:44:04When sound waves bump into a sunspot region,
0:44:04 > 0:44:07something remarkable happens.
0:44:07 > 0:44:08They speed up.
0:44:11 > 0:44:15In this case, the acoustic waves propagate a little bit faster
0:44:15 > 0:44:17in this region, inside the sunspot region.
0:44:17 > 0:44:21So the total travel time is a little bit shorter.
0:44:21 > 0:44:24This is 12 to 16 seconds shorter.
0:44:24 > 0:44:28And this is an indication that there is a sunspot region
0:44:28 > 0:44:31along the acoustic path.
0:44:31 > 0:44:34Now, in reality, we don't know where the sunspot is,
0:44:34 > 0:44:37so we don't select only one pair of points,
0:44:37 > 0:44:41but we select thousands of pairs of points on the solar surface,
0:44:41 > 0:44:45we compute the travel times, and we identify locations
0:44:45 > 0:44:49where the travel time is significantly shorter.
0:44:49 > 0:44:54That shows that there is a large sunspot region at these locations.
0:44:54 > 0:44:59So we have one to two days' extra warning
0:44:59 > 0:45:03before the sunspots appear at the surface and become dangerous.
0:45:05 > 0:45:10But Stathis is not satisfied to stop at two additional days' warning.
0:45:10 > 0:45:13He believes that in future he can go even deeper,
0:45:13 > 0:45:17listening for storm-bearing sunspots far earlier.
0:45:20 > 0:45:24Apparently, we can only detect sunspots at a depth of 60,000km.
0:45:24 > 0:45:28And this gives one to two days' heads-up
0:45:28 > 0:45:30before they appear on the solar disc.
0:45:30 > 0:45:33So in the future, we hope to refine this technique,
0:45:33 > 0:45:37and detect sunspots much deeper than 60,000km.
0:45:37 > 0:45:40And this can give a week of extra warning,
0:45:40 > 0:45:42before they appear on the solar disc.
0:45:46 > 0:45:49It sounds like a brighter, safer future,
0:45:49 > 0:45:53if one day we can rely on Stathis' technique to warn us.
0:46:05 > 0:46:09And in this fast-evolving technological age,
0:46:09 > 0:46:12this warning is becoming more and more critical.
0:46:18 > 0:46:20John Kappenman has spent the last 30 years
0:46:20 > 0:46:24studying exactly what could happen to our modern world.
0:46:25 > 0:46:30We think these large storms are something that is probable
0:46:30 > 0:46:34in a one-in-50 to one-in-100-year sort of basis.
0:46:34 > 0:46:40It's really only over the last half century or so
0:46:40 > 0:46:45that we've grown this very large interconnected infrastructure.
0:46:47 > 0:46:50What's coming more to the fore now is this immediate need,
0:46:50 > 0:46:53given our technological society,
0:46:53 > 0:46:56we need to study the impact of the sun on the Earth.
0:46:58 > 0:47:04Big storms have occurred before and they are certain to occur again.
0:47:04 > 0:47:10The difference is that we've now built a big vulnerable infrastructure
0:47:10 > 0:47:14that impacts all of society.
0:47:21 > 0:47:25And key to our new vulnerable infrastructure are these...
0:47:25 > 0:47:27Satellites.
0:47:27 > 0:47:29Our modern world is built on them.
0:47:31 > 0:47:33Navigation, communications,
0:47:33 > 0:47:36plus everything from warfare to banking relies on them.
0:47:40 > 0:47:46Satellite electronics can be destroyed by space weather storms.
0:47:56 > 0:48:00But space weather can also affect our atmosphere,
0:48:00 > 0:48:03plucking a satellite out of its orbit
0:48:03 > 0:48:05and sending it crashing to Earth.
0:48:17 > 0:48:21A remote Arctic monitoring station,
0:48:21 > 0:48:24home to an ambitious project.
0:48:37 > 0:48:41A project to protect our civilisation,
0:48:41 > 0:48:44350km inside the Arctic Circle.
0:48:45 > 0:48:48It's a place on the planet where you can test something
0:48:48 > 0:48:51that could end up protecting our satellites.
0:48:58 > 0:49:02Norway, northern Norway, is very good for these types of experiments,
0:49:02 > 0:49:06because we're in the high polar region,
0:49:06 > 0:49:08and it's in the high polar regions,
0:49:08 > 0:49:12that the Earth's magnetic field comes down to ground, almost vertically.
0:49:12 > 0:49:13And this is very important,
0:49:13 > 0:49:16especially when you're doing radar experiments,
0:49:16 > 0:49:20so that you can map along the magnetic fields, out into space,
0:49:20 > 0:49:22several thousand kilometres,
0:49:22 > 0:49:25and that's not possible anywhere else on the Earth.
0:49:29 > 0:49:32Mike Kosch is attempting to do something artificially,
0:49:32 > 0:49:35invisibly, that happens naturally up here.
0:49:47 > 0:49:52The aurora is caused by particles coming from space,
0:49:52 > 0:49:55crashing into the top of the Earth's atmosphere.
0:49:55 > 0:49:57These particles come from the sun,
0:49:57 > 0:50:00they get trapped on the Earth's magnetic field,
0:50:00 > 0:50:03and because the magnetic field in polar regions,
0:50:03 > 0:50:06comes down to the Earth's surface vertically,
0:50:06 > 0:50:10the particles can track along those magnetic field lines,
0:50:10 > 0:50:13down in the polar regions, into the atmosphere.
0:50:16 > 0:50:20When they collide with the oxygen and nitrogen that we're breathing,
0:50:20 > 0:50:25they activate those gases, which causes optical emissions to appear.
0:50:25 > 0:50:31Red and green, typically, is for oxygen, blue is for nitrogen.
0:50:34 > 0:50:40The aurora is just the most beautiful and surreal experience.
0:50:43 > 0:50:47The same process that creates the aurora
0:50:47 > 0:50:50happens much more powerfully during a solar storm.
0:50:53 > 0:50:56Mike is using this massive dish to precisely measure
0:50:56 > 0:50:59how a solar storm changes our atmosphere
0:50:59 > 0:51:02and the threat that this poses.
0:51:04 > 0:51:08When that wave of material comes towards the Earth,
0:51:08 > 0:51:12it heats the atmosphere and that causes the atmosphere to expand.
0:51:15 > 0:51:19This expansion makes the region of the upper atmosphere
0:51:19 > 0:51:23satellites fly through, denser.
0:51:23 > 0:51:25The resulting extra drag
0:51:25 > 0:51:28can have serious consequences for our satellites.
0:51:29 > 0:51:32During a big storm,
0:51:32 > 0:51:36this expansion can increase the density of the gases here tenfold.
0:51:38 > 0:51:40The results can be catastrophic
0:51:40 > 0:51:46for any satellite flying through this region after a storm has hit.
0:51:47 > 0:51:50Forced to travel through a thicker gas,
0:51:50 > 0:51:54satellites can be dragged out of their orbit to crash to Earth.
0:51:56 > 0:52:00In 1979, even Skylab was vulnerable.
0:52:00 > 0:52:04The upper atmosphere Skylab was travelling through
0:52:04 > 0:52:07was heated by a series of solar storms.
0:52:07 > 0:52:11Eventually she crashed uncontrollably to Earth.
0:52:28 > 0:52:32Now we're not always in a position to wait for space storms to come
0:52:32 > 0:52:36so we have another instrument here on site called the heater
0:52:36 > 0:52:40and we can then simulate these space weather events, using the heater,
0:52:40 > 0:52:43to heat the atmosphere at high altitudes,
0:52:43 > 0:52:45cause the atmosphere to expand,
0:52:45 > 0:52:47so that we can study the atmospheric expansion
0:52:47 > 0:52:49and therefore the effect on satellites.
0:52:55 > 0:52:58Mike is ready to run the experiment.
0:52:58 > 0:53:02If successful, this will be a scientific first,
0:53:02 > 0:53:05one that could lead to a new type of forecast
0:53:05 > 0:53:08that could keep our satellites from crashing in future.
0:53:13 > 0:53:16This experiment has never been done before,
0:53:16 > 0:53:19so we're not quite sure if the experiment will work.
0:53:19 > 0:53:21We're a little bit worried and a little bit nervous
0:53:21 > 0:53:24about whether we may get a good result or not.
0:53:28 > 0:53:33..nine, eight, seven, six, five,
0:53:33 > 0:53:37four, three, two, one, now.
0:53:37 > 0:53:39OK, roll on.
0:53:43 > 0:53:45Yeah, something's happening certainly.
0:53:45 > 0:53:48You could definitely see how the density was going up.
0:53:51 > 0:53:53I think there's Langmuir turbulence here,
0:53:53 > 0:53:56and I think we may be producing suprathermal electrons.
0:53:56 > 0:53:58Yeah, but what's the flow doing?
0:54:00 > 0:54:04After several hours heating the atmosphere in 15-minute bursts,
0:54:04 > 0:54:06the team have gathered the findings.
0:54:09 > 0:54:11Well, it's 8.00 in the evening
0:54:11 > 0:54:14and we've just completed running this new experiment,
0:54:14 > 0:54:18and we have the initial results on the screen here, from the radar.
0:54:18 > 0:54:22When you heat the atmosphere you heat a gas, you expect it to expand.
0:54:22 > 0:54:26So if the gas is expanding and the atmosphere is lifting,
0:54:26 > 0:54:31then you would expect at the altitude that a satellite normally flies,
0:54:31 > 0:54:34that the density would be increasing.
0:54:34 > 0:54:36And you see that very clearly over here.
0:54:36 > 0:54:38This is the panel that shows density.
0:54:38 > 0:54:42The red colours, let's say 500km,
0:54:42 > 0:54:45where a satellite normally flies, indicate high density,
0:54:45 > 0:54:47and every time we turn the heater on,
0:54:47 > 0:54:50we see that the density is increasing.
0:54:50 > 0:54:52Now, the importance of this experiment
0:54:52 > 0:54:54is that we can make this measurement very precisely.
0:54:54 > 0:54:58So when we see a space weather storm, a space weather event,
0:54:58 > 0:55:01coming from the sun, we can estimate the amount of energy,
0:55:01 > 0:55:04the amount of heat it is bringing to the Earth,
0:55:04 > 0:55:07and therefore we could make an accurate calculation
0:55:07 > 0:55:11of what the density increase would be, for a satellite.
0:55:14 > 0:55:17So if we can predict that accurately,
0:55:17 > 0:55:19then the operator of a satellite
0:55:19 > 0:55:22would be able to make a correction, take some action,
0:55:22 > 0:55:26for example, fire the rocket engines, to compensate for the drag,
0:55:26 > 0:55:29and therefore prevent the satellite from crashing back to the ground.
0:55:29 > 0:55:31That's the important point here.
0:55:36 > 0:55:39With such a precise level of data,
0:55:39 > 0:55:42Mike hopes to provide the Space Weather Prediction Centre
0:55:42 > 0:55:47with a real-time feed of atmospheric density to give satellite companies
0:55:47 > 0:55:51enough information to protect their satellites.
0:56:03 > 0:56:06Now that we are looking more closely,
0:56:06 > 0:56:09listening more deeply,
0:56:09 > 0:56:11measuring more precisely,
0:56:11 > 0:56:15a new question is coming into focus -
0:56:15 > 0:56:19what solar storms can we expect in the distant future?
0:56:24 > 0:56:28Back in Tucson, the scientists know the next two years
0:56:28 > 0:56:29could see more solar storms.
0:56:31 > 0:56:34What they are now trying to understand
0:56:34 > 0:56:36is what's happening over the next half century.
0:56:38 > 0:56:41So what we've seen is an overall decrease
0:56:41 > 0:56:44in the magnetic field strength inside sun spots.
0:56:44 > 0:56:47Now, during any given year, sun spots appear on the disc of the sun
0:56:47 > 0:56:51that have a variety of magnetic field strengths.
0:56:51 > 0:56:54But if you take the sun spots that you see in an entire calendar year,
0:56:54 > 0:56:56and average the magnetic field strengths,
0:56:56 > 0:56:58and then look at that average magnetic field strength
0:56:58 > 0:57:01over the past 13 years, it's decreased very steadily.
0:57:01 > 0:57:04Now if we extrapolate this into the future,
0:57:04 > 0:57:07eventually we'll see only half of the number of sunspots
0:57:07 > 0:57:10that we're used to. And if it continues even further,
0:57:10 > 0:57:13the sun won't be able to form dark sun spots on its surface.
0:57:13 > 0:57:18So in general, we would expect less energetic solar storms to be erupting
0:57:18 > 0:57:20and perhaps space weather will be calmer in the future.
0:57:22 > 0:57:25I got rid of this 15,
0:57:25 > 0:57:27so that's really good, I should be able to go back now.
0:57:27 > 0:57:31But the complexities of predicting the future of the solar climate
0:57:31 > 0:57:34mean a definitive scenario is hard to come by.
0:57:34 > 0:57:37Back at the Space Weather Prediction Centre,
0:57:37 > 0:57:41they are not waiting for the sun to calm down.
0:57:42 > 0:57:45There are some people that say we're going to go into what's called
0:57:45 > 0:57:49a grand minimum, we're going to see well below average solar cycles.
0:57:49 > 0:57:51I think those are very controversial at the moment.
0:57:51 > 0:57:55There are many people that say the sun is not predictable
0:57:55 > 0:57:59on that long a time scale. It doesn't matter, though.
0:57:59 > 0:58:01Space weather is always happening and in fact
0:58:01 > 0:58:03severe space weather can happen,
0:58:03 > 0:58:07outside of a large sunspot number sort of period.
0:58:07 > 0:58:10We can never take our eye off the ball.
0:58:12 > 0:58:14We may be more vulnerable
0:58:14 > 0:58:17but we've never been better prepared.
0:58:20 > 0:58:26One thing is certain - we ignore this phenomenon at our peril.
0:58:39 > 0:58:42Subtitles by Red Bee Media Ltd