Original subtitles

It rises in the east and bathes our planet in light. It

powers the machinery of nature, our weather, encourages and

sustains life on land and at sea where it warms our oceans

from pole to pole. When it sets in the west, it reveals to

us its many billions of sibling stars, populating the night

sky. We study our sun closely, and like a Rosetta stone, it

can reveal the secrets of all the stars.

You cannot study the sun in isolation.

The influence of its power throughout the solar

system it created is persuasive and dominating.

The heliosphere is an immense magnetic bubble extending

beyond the orbit of Pluto. It contains the solar wind of

high and low-speed energetic particles and

plasma that originate at the surface of the sun.

After traveling for 36 years and 19 billion kilometers,

the Voyager 1 spacecraft has reached the edge of this

heliosphere.

Voyager 1 has left the bubble around the sun and entered

interstellar space, the space between stars. There it still

senses the shock waves emitted by the sun, which sound like this.

To understand this source of power and its influences,

scientists conduct observations from the ground and in

space, where a flotilla of satellites trains sophisticated

sensors upon the sun and the space weather it creates. Space

weather is the field that studies how what's going on on

the sun affects us here on the earth in our near space

environment and on the space environment on other planets.

The effects of space weather are so complicated because we

have to understand what's going on at the sun as well as all

that stuff traveling through interplanetary space, how that

affects and throughout the heliosphere, that we need

an entire fleet of instruments to look at these various

effects. It's basically a system science, so you understand

one part of it in order to understand the other part of it,

and you have to put that whole puzzle together

to understand the full effects of space weather.

GOES-P is an ongoing series of Earth observation satellites

that happen to keep a constant eye on the sun, monitoring

this space weather. So the spacecraft sitting in space, it's

looking down at the earth and it stays stationary like this,

but this solar array out here moves and tracks the sun, so

that way it's always looking at the sun and can take a scan

every minute. The sun's outer atmosphere is constantly being

heated up by the solar surface, and this causes particles

from the sun's atmosphere to stream away constantly. These

streaming particles, which are filling our entire solar

system, are called the solar wind. Different phenomenon from

the sun is constantly bombarding the earth. Although you

might not know it, the solar weather affects you every day

down here as well, not only just astronauts, it affects

people on earth. The latest generation of GOES

satellite is the GOES-R, soon to be launched into orbit.

Other low-air-forbiting platforms include ESA's micro

-satellite PROBAT-2, testing new technology, and PICAR,

sponsored by CNES, the French space agency.

Hinode is the Japanese word for sunrise. It is a joint

mission between JAXA, NASA and ESA to study the sun's

magnetic cycles. Its close-up study has revealed the complex

granular textures of the sun's surface and insights into

solar flares.

A solar flare is a huge release of energy that converts

the magnetic energy of the sun into heat, into light, it

accelerates particles, and can really heat up the plasma

in order of minutes to over 60 million Kelvin. For a large

eruption, the sun produces a flash of light, which we call

the solar flare. It also produces a huge ball of material

traveling away from the sun we call coronal mass ejection.

And both of those phenomena can accelerate subatomic

particles, which we call solar energetic particles.

These three things together make up a solar storm.

To study the solar wind phenomenon, a group of satellites

were placed in a unique orbit between Earth and the sun at

what is called L1, or Lagrange Point 1, a point of

gravitational balance between the Earth and the sun. The

Advanced Composition Explorer, or ACE, observes energetic

solar particles. Wind studies radio waves and plasma that

occur in the solar wind and in the astromagnetosphere

and SOHO, the Solar and Heliospheric Observatory.

Using SOHO and using technique called helioseismology, very

similar to seismology on the Earth, we're actually able to

see inside the sun. And so what we were able to do is see

the layer of the sun just below the visible surface that we

call the convection zone. And that's where all sorts of

dynamics are going on. The inside of the sun is bubbling up

to the surface. And that's really where all of the solar

phenomena that we see is first developed. And so we were

able to see underneath the surface and see these flows of

solar plasma, see the formation of sunspots. And this is

something that's never been done before. We're actually able

to see the details inside of a star. Another high-resolution

space telescope was TRACE. You're seeing details of the

coronal loops. In the previous images from other satellites,

it would look like it was just one big loop. And when you're

actually going to see TRACE, you can see it's all these

teeny tiny, finely, they almost look like threads. And

there's these teeny tiny loops. And they're just breaking

off and reforming and throwing plasma. Using X-ray and gamma

ray solar flare imaging, RISI explores the particle physics

behind solar flares. Another event subjecting the solar

system to bombardment is the CME, or coronal mass ejection,

event. A coronal mass ejection, or CME, is an eruption of

plasma from the sun that shoots out into space. And it could

affect us here at Earth if that big ball of plasma were to

hit us. NASA's twin stereo mission has one spacecraft orbit

the sun ahead of the Earth and the other behind, providing

a stereoscopic view of the sun to better understand these

coronal mass ejections and the energetic particles of

plasma. Solar energetic particles are particles of plasma

that are accelerated at the flare site from the energy

that's released in the flare. And these particles can be

accelerated up to almost 80% of the speed of light. And a

coronal mass ejection, when it's traveling so fast, creates

a shock. And that can create solar energetic particles. In

2009, NASA commenced a new scientific program called Living

with a Star.

The crown jewel of this program is the Solar Dynamics

Observatory, or SDO, the most advanced spacecraft ever

designed to study the sun and its dynamic behavior.

The program's goal is to develop the scientific

understanding necessary to address those aspects of the sun

that directly affect us here on Earth. The spacecraft

provides 16-megapixel ultra-high-definition imagery of the

sun in 13 different wavelengths. From extreme ultraviolet

frequencies to the helioseismic and magnetic imager and the

atmospheric imaging assembly, each wavelength was selected

to highlight a particular part of the sun's atmosphere. The

results are stunning. They reveal fine details from the

solar surface to the upper reaches of the sun's corona.

These solar events dwarf our planet, and the science has

brought a renewed focus back to Earth's protective magnetic

field. We are protected here on the surface of the Earth

from solar flares and coronal mass ejections when they

impact the Earth due to the magnetic field of the Earth

called the magnetosphere, which deflects the magnetic field

and the energetic particles, as well as the atmosphere,

which absorbs the higher levels of radiation. Fortunately,

we are protected here at Earth from flares and coronal mass

ejections by the Earth's outer atmosphere. It absorbs a lot

of the energy from the increased light from solar flares,

but we're also protected by the magnetic field. You know,

the Earth has a north pole and a south pole. Anyone who has

a compass knows that. But this magnetic field of the Earth

also protects us from these charged particles, the plasma,

coming from coronal mass ejections that largely deflects a

lot of this direct energy. A coronal mass ejection will

come and affect the Earth's magnetic field, and changing and

hitting the Earth's magnetic field causes other changes

on the actual far side away from the Earth that then

accelerates more particles and shoots those particles

then into the north and south pole that produce these very

beautiful waves of green and blue and red that are just lovely to see.

The sun is powered by a process called fusion, and that

happens at the very core of the sun, where it is so intense,

so hot, and so dense that protons fuse together and create

helium. And this process fuels the sun and creates energy.

As the energy moves outward, boosted by magnetic fields,

the temperature drops. Up until that point, everything makes

sense in that the hottest part is in the middle and

everything gets gradually cooler as we move away, but then

something very interesting starts to happen, which is

that it starts to get hotter again. This layer, where the

temperature begins to rise again, is called the

chromosphere. It lies between the photosphere and the

corona, which is the hottest part of the sun's atmosphere.

To discover how this corona is powered, another mission

called IRIS was launched in 2013.

IRIS carries a single ultraviolet telescope and imaging

spectrograph, whose tight resolution allows it to see

features as small as 240 kilometers on the sun's surface.

IRIS's first images showed a multitude of thin, fibril-like

structures that have never been seen before, revealing

enormous contrasts in density and

temperature occurring throughout the region.

The light from the chromosphere is difficult to interpret

because of the complicated interaction that the light has

with the matter. It bounces around, if you will, many times

before its final bounce towards us. This means that that

interaction between light and matter needs to be modeled

in great detail. Due to not just advances in computational

power of computers, but in the computational techniques that

have been developed by the IRIS team, we are in a position

to do this. Data collected from the IRIS spacecraft has

shown that the interface region of the sun is significantly

more complex than previously known. Although the corona is

extremely hot, millions of degrees, it's at a low density,

so it doesn't actually take a lot of energy to heat it to

that temperature. The chromosphere, on the other hand, is a

much higher density, albeit lower temperature, and there's

much more energy deposited in the chromosphere than in the

corona, so that a tiny fraction of that energy in the

chromosphere escaping into the corona is plenty to power all

of the processes that we see, from heating to such extreme

temperatures to driving the solar wind that fills the whole

solar system, impacting all the planets, including our own.

We hope to better understand these fascinating and important

processes with IRIS.

This energy streaming from the sun causes other

knock-on effects on the planets of the solar system.

The northern lights are particles that are being shot

into the North Pole and the South Pole that produce these

beautiful greens and blues and reds. They're not direct

particles from the sun. A coronal mass ejection will come

and affect the Earth's magnetic field, and changing and

hitting the Earth's magnetic field causes other changes on

the actual far side, away from the Earth, that then

accelerates more particles and shoots those particles then

into the North and South Pole that produce these very

beautiful waves of green and blue and red that are just

lovely to see. Armed with more questions about the solar

wind and energetic particles, NASA launched a pair of probes

into Earth orbit. Named after the famous scientists who

discovered the radiation belts surrounding our planet, the

Van Allen probes were dispatched to study the radiation

phenomenon and the magnetic fields around the Earth in

greater detail. During the course of geomagnetic activity,

disturbances caused by flares on the sun, by big blobs of

plasma coming out from the sun towards the Earth, the

Earth's magnetic field is battered and shaken. Some of that

energy is captured in the Earth's magnetic field, and

through a variety of processes, that energy energizes

particles in the Earth's radiation belts up to energies

that are hazardous to spacecraft and astronauts. The two

spacecraft are focused on the dynamic radiation belts in

the Earth's inner magnetosphere. They're the only spacecraft

that focus on those. Consequently, they're a critical

component in the series of phenomena that link the sun to

the Earth.

Solar flares and CMEs are all driven by magnetic

reconnection. This is where the sun turns up the magnetic

field that's inherent in it, and then it causes oppositely

directed magnetic fields to then annihilate. But you can't

just get rid of energy, you have to convert that energy

and transfer that energy into other things such as plasma

motions, accelerating the plasma, heating up the plasma,

and also giving out more light. We are protected here on the

surface of the Earth from solar flares and coronal mass

ejections when they impact the Earth due to the magnetic

field of the Earth called the magnetosphere, which deflects

the magnetic field and the energetic particles, as well as

the atmosphere, which absorbs the higher levels of

radiation. But this magnetic field of the Earth also

protects us from these charged particles, the plasma coming

from coronal mass ejections that largely deflects a lot of

this direct energy. The phenomenon of magnetic reconnection

is not well understood. So NASA has launched a multi

-satellite mission called MMS to try to unlock the secrets

of our magnetic field. The MMS mission is a mission

consisting of four spacecraft which will fly in close

constellation to measure a process called magnetic

reconnection. The universe is full of plasma, and it's full

of magnetic fields, and all over the place in the universe

you have one plasma colliding with another. An example of

that is the solar wind coming in and colliding with Earth's

magnetosphere. And then the magnetic energy in the plasma,

some fraction of that magnetic energy is converted very

rapidly into plasma energy. So you can think of it as

kind of like a magnetic explosion. And the reason this is

important is because these explosions drive a lot of the

weather patterns that we see in the magnetosphere, and so

what space scientists like to refer to as space weather.

And these space weather phenomena can have impact on our

everyday lives. It can actually affect communication

satellites, the power grid. So we'd really like to

understand how these magnetic explosions work. We need to

measure reconnection in more than one location. We need to

measure basically how it varies in space, how it varies

in all three spatial dimensions. And that requires a

tetrahedron. The additional fantastic benefit that that

provides is that it will actually enable us to recognize

that we are looking with a reconnecting region much easier

than a single spacecraft. The ideal situation is that we

would like the four spacecraft to kind of be surrounding

this region where the explosion is happening. So the

separation of the spacecraft is about 10 to 100 kilometers,

which may seem like a long distance. But in terms of the

magnetosphere, which is absolutely huge, this is really a

microscopic region that we're trying to cover. MMS has in a

nutshell two orbital phases which are designed to study

reconnection. On the day side, basically you have a

situation where the solar wind is just constantly running

into Earth's magnetic field. And this is really great for

MMS because we know that at some point MMS is going to

encounter this region. And our hope is that since this

process is always happening, we're going to get lucky and

actually fly right through the magnetic explosion as it's

happening. Now on the night side, the situation is a little

bit different. So what happens is you have a more gradual

buildup of magnetic energy in the tail. And these

reconnection processes, these magnetic explosions, can just

sort of pop off randomly. We don't really know when it's

going to happen or where it's going to happen in the tail.

We need to understand both of those if we want to understand

how the magnetosphere works. And we believe that both of

those scenarios are also very important for other

applications, such as on the Sun, in the solar wind, in

planetary magnetospheres, and in many astrophysical objects,

as well as in the laboratory. We hope that it's going to

allow us to improve our models so that we can put the right

physics in it and actually make predictions about where and

when reconnection is going to happen. The magnetic

explosions will help us make our space weather models more

predictively powerful. The instruments that are actually

going to be measuring the particles in space are collecting

them much more rapidly at a much higher cadence than they

have on previous missions, about a factor of 100. So whereas

it would take a previous generation particle instrument

about three or four seconds to build up a whole picture of

the sky, it's going to take MMS about 30 milliseconds.

So it really is sort of game-changing technology.

The current two dozen or so operating satellites will be

enhanced with new missions under development. The Japanese

Space Agency will be launching their next solar physics

satellite, Solar-C. The Indian Space Agency will be

launching Aditya to study the Sun's coronal mass ejections

and magnetic field structures. The Deep Space Climate

Observatory will maintain real-time solar wind monitoring

capabilities critical to the accuracy and lead time of space

weather alerts and forecasts. The European Space Agency's

Solar Orbiter will be launched in 2018 and fly closer to the

Sun than the planet Mercury to study how the

Sun creates and controls its heliosphere.

Also planned for a 2018 launch is NASA's Solar Probe Plus.

It will approach the Sun more closely than any other probe

before, just 3.8 million miles from the surface of the star.

Scientists have long wanted to send a probe through the

Sun's outer atmosphere. The spacecraft will be exposed to

temperatures approaching 1,370 degrees Celsius. Together

they will continue to monitor, study and discover the

secrets of this nuclear anvil that supplies us with light and life.

Aside from the science, the images captured reveal to us

the beauty and power of this, our nearest star in all its

grandeur.

NASA Jet Propulsion Laboratory, California Institute of

Technology California Institute of Technology California

Institute

of Technology