on september 1st 1859 a gigantic
explosion on the sun
sent radiation and matter flying towards
earth resulting in one of the largest
geomagnetic storms on record
the auroras that night were bright
enough to read by and were visible as
far south as hawaii but the real impact
came from the disruption of the
telegraph system
across europe and north america
telegraph systems failed
in some cases shocking their operators
or throwing sparks from their machinery
what in the world or should i say
universe
caused this crazy storm and should we be
worried about it happening again
[Music]
so we know the sun produces energy as
light and heat
but we don't often think about all of
the wild things happening
on and below its surface and some of
those things can affect us
all the way down here on earth our sun
is a yellow dwarf star
so large that the volume of 1.3 million
earths could fit inside of it
but if we travel deep inside our sun the
temperature is 15 million degrees
celsius
which is hot and dense enough to fuse
hydrogen atoms into helium
a process called nuclear fusion that
gives off massive amounts of energy
but today we're more interested in
what's happening on the relatively
cooler surface of the sun called the
photosphere
let's back up a little bit a little more
just a touch farther
that's better the surface of the sun is
5500 degrees celsius
and covered in gases that are constantly
moving and changing
it's covered by a thin layer called the
chromosphere this layer is usually hard
to
see but can be seen as bright red when
viewed with specific light filters or
during a solar eclipse
right above that is the corona the super
hot outer atmosphere of plasma that
looks like a crown or
corona during a solar eclipse the corona
extends far above the surface of the sun
eventually merging into the solar wind
that moves throughout the solar system
[Music]
these images from nasa's solar dynamics
observatory were taken with special
telescopes that allow us to look at the
solar atmosphere
in many different wavelengths of light
each telling us something a little
different about what's happening
and if you look at these many different
images you'll see that there are giant
explosions
big spots and huge loops of plasma
all over the sun's surface
so what is up with the sun it's doing
some
wild and seemingly mysterious things
well hot electrically charged plasma
flows within the sun
constantly moving the movement of these
charged particles
creates currents and these electrical
currents create magnetic fields
this phenomena of turning motion into
magnetism is called a dynamo
and so the sun's magnetic field is a
result of the solar dynamo
compared to earth's relatively tame
magnetic field with just a north and
south pole
these looping twisting fields of
magnetism on the sun are far more
dynamic
in this image of the sun you can see
lots of looping lines that seem to come
off of its surface
these are prominences giant loops of
plasma that stretch out from the sun's
photosphere
the plasma is composed of electrically
charged hydrogen and helium
these prominences follow the sun's
magnetic field lines and extend out into
the corona the sun's extended atmosphere
scientists are still trying to figure
out exactly how and why
they happen oh and these prominences are
huge just look at this image of earth
superimposed for scale
but prominences are just the start of
weird things happening on the sun
see these dark spots they're called
sunspots and what's happening inside of
them is
really crazy these are areas where the
magnetic field of the sun has become
so great that it causes the atmospheric
pressure in the area to decrease
what happens is the intense magnetic
field prevents hot gas from the center
of the sun from flowing outward towards
the surface
creating a cool spot on the sun that
appears darker than the surrounding
areas
sometimes astronomers will observe rapid
intense changes in brightness on the
surface of the sun
like this these are solar flares
solar flares are intense bursts of
radiation from the sun that occur when
huge amounts of stored magnetic energy
are rapidly released solar flares create
intense bursts of light that can last
for minutes or for hours
and often occur near sunspots sometimes
when this magnetic energy is released
eruptions on the surface of the sun can
also send billions of tons of solar
matter
flying out into space this is called a
coronal mass ejection or
cme these send giant clouds of
magnetized particles
hurtling out into space flares and cmes
often happen together
with a bright flash followed by the
giant arcing explosion
but cmes can also happen on their own
and these can be
big explosions cmes can contain a
billion tons of matter and can travel
faster than 5 million miles per hour
they can accelerate protons and
electrons ahead of them as they travel
towards us
creating storms of these fast-moving
high-energy particles
and despite the sun being 93 million
miles away
all of these solar weather events can
still have effects right here on earth
from stunningly beautiful auroras to
radio blackouts
light x-rays and gamma rays from a flyer
arrive at the earth in just 8 minutes
but cmes can take hours to days to
arrive
bombarding the earth with charged
particles and magnetic field from the
corona
thankfully our atmosphere and
magnetosphere protect our fragile human
bodies
from most of this fast-moving particles
from the sun
interact with the earth's magnetic field
and particles trapped in our local space
environment
eventually the energy transfer results
in charged particles colliding with
oxygen and nitrogen in our uppermost
atmosphere
causing auroras like the northern lights
and the emitted light is specific to
each molecule oxygen atoms typically
give off a greenish yellow or red light
nitrogen atoms give auroras a blue hue
and nitrogen gas can appear a reddish
pink
usually you can only see auroras towards
earth's poles
this is because earth's own magnetic
field lines direct the stream of
incoming particles towards the poles
but sometimes a solar event is so big
you can see it across the world
and that's what happened in 1859 richard
carrington an amateur astronomer
was peering through his telescope and
sketching out sunspots
when he noticed two bright white patches
erupting from the spots
these two flares disappeared in about
five minutes but caused the biggest
recorded geomagnetic storm
early the next morning just before dawn
stunningly bright auroras appeared
across the world
visible as far south as cuba the bahamas
and hawaii
people in the northeastern u.s reported
being able to read the newspaper by the
light of the auroras alone
and a baltimore newspaper described the
city being lit up as if under a luminous
cloud
but as beautiful as they were they also
caused huge disruptions to the telegraph
system
and yes as you're watching this on
youtube that might sound kinda quaint
but at the time it was a major method of
communication
in its simplest form a telegraph is a
transmitter and a receiver
connected by an open circuit we talked
more about circuits in our episode about
the world's biggest batteries
you can send a telegraph message by
pressing down on a transmission key
which completes the circuit this sends
an electric pulse to the receiver
which causes an electromagnet in the
receiver to attract a small iron arm
whose movement makes a mark on a paper
by tapping away in morse code you can
send messages over long distances using
electricity
so yeah gigantic bursts of
electromagnetic radiation from the sun
can kind of mess with a system based on
sending precise electric signals
[Music]
when a cme reaches our planet the
gigantic blob
of solar atmosphere and magnetic field
rattles the earth like a bell
generating electric currents both in our
atmosphere and
in long conductors like pipes and power
lines this is what created
the massive electrical currents that
overwhelmed the telegraph system
causing some to shoot out sparks and
even lighting the telegraph paper on
fire in places
many lines stopped working but some
telegraph operators reported that the
aurora induced currents allowed them to
transmit messages
even after they had unplugged the
batteries from their machines
but first-hand accounts aren't the only
way to investigate past
geomagnetic storms sometimes we can see
the side effects of giant solar storms
trapped in ice
cmes act like giant bulldozers plowing
through interplanetary space
pushing big waves of high-energy
particles including protons and
electrons ahead of them
when these particles collide with the
atoms and molecules in our atmosphere
they create radioactive atoms some like
carbon 14
are incorporated into living organisms
and let us do things like carbon dating
and if you want to watch more about the
chemistry that enables carbon dating
check out our episode on lake nios
but beyond just carbon 14 these storms
of particles can create radioactive
isotopes like beryllium 10 and chlorine
36
which can then fall down to earth and
become locked in ice
by drilling cores into the ice in
undisturbed areas like antarctica and
greenland
scientists can find evidence of these
particle storms associated with cmes
that happened
long before we were able to track them
with modern technology
in fact ice cores have shown evidence of
three major solar storms in 994 ce
775 ce and 660 bce
all three were also corroborated by
spikes in radioactive carbon found in
tree rings
while early evidence showed that there
may also be a trace of the 1859 event in
an ice core
it's more likely that what the
scientists saw was in fact due to large
amounts of burning biomass
like large forest fires in north america
which could mean
that these other three events were much
much bigger than the 1859 event
so should we be worried about another
event like this happening and
wiping out all of our technology we've
progressed quite a bit since the
telegraph
but that really just makes us more at
risk if something of this skill were to
happen today
your phone the internet gps radios
credit cards the transformers that help
supply power to your home
all of these could be affected by a big
enough geomagnetic storm
and the biggest fear is that these solar
storms could affect the power grid
which would affect anything that relies
on electricity
so basically everything
and we've had a relatively recent taste
of what this could do to our modern
systems
in the 70s a cme knocked out long
distance telephone lines in illinois
another one in 1989 disrupted a power
plant in quebec
causing a large blackout and in 2005
a solar storm disrupted the
satellite-to-ground gps navigation
system
for 10 minutes and while that doesn't
sound like very long
that's a pretty big problem since
everything from boats to planes to
farming equipment to the entire
financial industry
relies on gps every single day
some estimates have found that a cme the
size of the one that happened in 1859
could cause trillions of dollars of
damage if it were to hit our
technological infrastructure today
but these events are really rare and
with early warning we can prepare for an
incoming solar storm
power companies airlines shipping
companies and others
are all aware of the risks and work with
space agencies to keep tabs on what
might be coming
nasa's solar shield project started in
2010
uses spacecraft data to identify and
model cmes creating 3d images of them
that can help to predict
where and when they might strike this
can give power companies time to turn
their power grids off
saving them from damage easily
deployable temporary transformers could
also be set up in case of emergency
to quickly replace damaged parts of the
grid
and more innovative solutions have also
been proposed like launching
giant loops of conductive wire to space
to partially deflect
incoming particles and magnetic fields
so if a big solar storm does head our
way
don't worry we are much more prepared
today
than we were back in 1859
[Music]
you