What effect could a solar flare (or CME) have on the earth? | Ep#5 | AXA Research Fund


How can you survive
a solar meltdown? Greg Foot What’s your worst nightmare? Mine is a power cut in a lift. You’re trapped in a lift. What’s the first thing you do?
You go for the alarm button. Completely dead. You go for your mobile phone. Zero bars. Technology is letting you down.
There’s only one thing for it. Help! Guys! Hello? What would happen if the power cut
lasted for weeks or even months? But this could never happen, right?
Wrong. And the thing that could
cause it is right up there. A star of spectral class G and luminosity class V, the sun. The sun is our life source, but it’s also a ball
of uncontrollable energy. And if all that power was
unleashed in our direction, the effect on all our tech
will be something like that. Luckily for us,
there’s a community of researchers who study very real risks like these
and how to prevent them. Their work is supported by AXA, and one of their researchers
is Dr. Miho Janvier. She studies the sun and has
a look at how we can protect the technology that we depend on. Hi, Miho. Hi, Greg. This is some stunning
footage of the sun. Why is it such a threat? Did you see that? It’s a coronal mass ejection,
and this is the reason why I study the sun. These coronal mass ejections
of big clouds of charged particles are blasted away
from the sun to the other planets. And when they arrive on the earth
they can affect our satellites, telecommunication satellites,
as well as our power grid. We all reliant so much on electricity that we have to be careful
on how our sun’s behaviour is affecting us
here on earth. Okay, what is it that
you exactly look at then? What I’m trying
to do is to look at how the sun is generating
those big solar storms and how they impact the earth. Impact?
That’s a scary word. What would happen if it hit us? First, we would have
very energetic charged particles that would travel almost at light
speed from the sun to the earth, and that would have
fried electric systems on satellites. Then a few hours later, you
would have this big cloud of charged particles
travelling from the sun and heating the earth, creating
northern lights or southern lights. Beautiful, but they would
have induced very strong currents. Because they are so powerful,
they are melting the transformers. Until you replace those transformers, you can be out of power
for hours or for days. As Miho said, a CME,
a coronal mass ejection is a cloud of charged particles. When it hits the
earth’s magnetic field, it sends it going like crazy. When that changing magnetic field
hits metal on the earth, so wires, pylons, it causes
something known as induction. I can show you what that is
with this simple bit of kit. If this magnet represents
the changing magnetic field around a coil of metal on the earth,
you can see it induces a current. Now what’s happening
is the magnetic field is actually moving
the electrons inside the metal and causing the metal
to heat up ever so slightly. If you have
a big enough magnetic field, you can move the electrons enough
that it gets mega, mega hot. Like this induction furnace. Most power grids are running
at near to capacity, so even if a solar storm induced
just a small amount of current, it would be enough to blow the lot. Everything that relies on power
or satellites would be useless. Right, Miho? That’s exactly right, Greg. And this is why research like
mine is really important. It’s a bit like forecasting
the weather. You wouldn’t really go
out for a walk if you knew that a hurricane was
going to arrive, right? No. Similarly if we know
that a solar storm is directed towards the earth,
we can protect our devices by turning town the electricity grid
or the communication satellites, so that your stuff
and my stuff are all protected. I tell you what,
I am very glad that you’ve got us covered. Great to speak to you. Thanks, Miho. Bye, Greg. Really nice to talk to you. The AXA Research Fund supports
over 450 academic research projects, in 32 countries, to increase
the knowledge on risks that matter to us all. AXA Research Fund
Through Research, Protection AXA redefining / standards Thanks to Dr Miho Janvier
Solar Physicist

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