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INTERVIEW
WITH DR. TERRY KUCERA
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ACTIVITIES
Solar Terrestrial Interactions
I want to talk a little bit about solar activity,
I don’t know how many of you have heard about
sunspots? Sunspots are cool dark areas on
the surface of the sun which people have been observing
for a fairly long time. They are places on
the sun where the sun’s magnetic field
is very strong.
You have probably done things with magnets in class
or even the magnets on your refrigerator. Magnetism
is more important than that, it is part of what
makes the sun such an interesting and complicated. You
should never look directly at the sun but sunspots
can be observed in other ways.
Sunspots don’t affect us directly. What
affects us directly are shorter types of solar
activity. Solar flares which you may have
heard of and something called a coronal mass ejections
(CME) which is something we have only been able
to observe since we got out into space. Flare
are brightenings that occur close to the sun’s
surface and can release x-rays and even gamma rays. They
don’t get down to us on the earth’s
surface but they can affect our upper atmosphere
as well as our communications systems and spacecraft
that are orbiting the earth.
CME’s are essentially giant clouds of material
that blow of the sun at millions of miles an hour. They
carry part of the sun’s magnetic field with
them into the atmosphere and can interact with
the earth’s magnetic fields.
Maybe you never thought about the earth having a magnetic
field but it does. That is why compasses
work. Maybe you have looked at a compass
and seen that certain places are at north – the
earth has a giant magnetic field which is affected
by the sun’s magnetic field. If the
sun’s magnetic field emits a CME it can be
very chaotic and this can affect spacecraft. It
can also cause the Aurora.
If you live someplace in the north or south you can
see these lights sometimes at night. If you
don’t live in the right area, you can see
examples on the internet.
We call affects of solar activity on the earth “Space
Weather”. We are trying to predict
space weather because it does have affects on spacecraft
and can affect astronauts. It is important
to know for example when we will have a coronal
mass ejection because there is radiation associated.
We have been out in space studying the sun and coronal
mass ejections for a long time now. A lot
of research has been in the area between the sun
and the earth. We can see things happening
on the sun and we can usually tell when they are
coming towards the earth but we haven’t been
able to get a really full picture.
It is sort of like if you are on the ground and can tell
that a storm in coming – that is useful. But
what is really useful is the type of spacecraft that
is looking down on the earth. We can now tell if
a storm is coming before it is visible from the ground. |
