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Alex: Solar flares and coronal mass ejections do
not always hit Earth. They happen all over the sun and depending
on where on the sun they occur determines whether or not they're
going to travel towards the Earth. Phil: Some of them could be shot off to the side, and just miss
us completely. They could go up, they could go left. Some are
like curveballs, that a pitcher will throw. They could
seemingly come straight for us, and then miss us completely.
Alex: Space weather can have several different effects on the
Earth and the near-Earth environment. In space, it can create
dangerous radiation in the form of particles, which is detrimental
to the health of astronauts. These particles,
as well as solar flares, can cause cause damage to
satellites in near-Earth orbit. In addition,
electromagnetic disturbances created by geomagnetic storms
can affect power transmission on the ground, can also
disrupt communication. But space weather has
no direct effect on human beings themselves. Holly: 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. Phil: Most of the energy that's associated with a solar flare or
coronal mass ejection doesn't even reach the surface of the Earth. So even
the biggest of flares isn't going to affect you here at Earth.
Music. Alex: When a large solar eruption
occurs, there are generally three things that happen. Each of these takes
a different amount of time to reach the Earth. The solar flare, because
it's light, travels at the speed of light and takes approximately 8 minutes to reach
us. The solar energetic particles are traveling extremely fast
--close to the speed of light, but not exactly the speed of light--so they take
roughly 20 to 30 minutes to reach us.
The coronal mass ejection is much slower, and that takes about
1 to 4 days to reach us. Music.
Holly: The sun goes through what we call a solar activity cycle,
where every 11 years on average, it will go from a very low period of
solar activity--meaning sunspots and solar storms--to another period
of low activity, and in-between it goes through what we call solar maximum. At solar
maximum the sun has a very complicated magnetic field structure, and
therefore it creates a lot more sunspots and a lot more solar storms like flares,
and CMEs. It's very important to be able to
forecast solar events because they can affect our technology, our
satellites, they can cause power grids to be affected. So as we
become more and more technologically advanced, it becomes more important to be able to forecast
such events. Music
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