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Hi, I'm John and this is NASA Now for January 4, 2012.
Lately we have been hearing a lot of talk
about solar storms and solar flares.
So what's happening with our sun and how does it affect us?
We'll find out later in the program.
But first, here's what's happening at NASA Now.
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Last year, NASA's Solar Dynamics Observatory, commonly known
as SDO, provided stunning images of major activity on the sun.
The images showed a massive region on the sun
that scientists call the benevolent monster.
This area is one of the most active regions on the sun
and it produced huge solar flares.
A solar flare is a burst of electromagnetic energy
from the sun that has the potential
to disrupt communications
and electrical systems here on Earth.
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Ah, the sun!
It is a source of life on our planet.
It can also provide a bombardment of charged particles
and electromagnetic radiation that has the capacity
to disrupt telecommunications and power grids.
Here to dispel some misconceptions
and give us a much better understanding
of the sun is astrophysicist Mitzi Adams
at the Marshall Space Flight Center.
Hello Mitzi, how would you describe our sun?
The sun is a star.
It's actually a middle-aged star.
It's made of hydrogen and a little bit of helium
and some other trace elements.
It's all gas, but it's gas that's at a very special state
and it's gas that's actually producing energy.
What fuels the sun?
In the interior of the sun,
energy is produce by nuclear fusion.
This process takes part of a hydrogen atom,
which is a proton, and fuses another hydrogen atom together.
Does the sun have different layers just like our own planet?
The sun has an interior and the very middle
of the sun is called the core.
The core produces energy from nuclear fusion.
Outside the core you have a couple of more layers.
You have the radiative zone,
then you have the convective zone and at that point,
you've reached what we call the surface and we call
that layer the photosphere.
The chromosphere is above that and the corona,
the crown of the sun, is above that.
And in the photosphere, we see sunspots.
In the chromosphere, we can see prominences
and we can see flares and then
in the corona we see coronal mass ejections.
You mentioned coronal mass ejections, can you explain?
Coronal mass ejections are associated with solar flares
and this is when material actually escapes the
gravitational field of the sun and is propelled
out into interplanetary space.
And this material, which is made up of protons, electrons,
is traveling at very high rates of speed.
And if that coronal mass ejection is pointed towards the
Earth, we can have aurora, we can have problems
with our GPS systems, we can have problems
with airplanes needing to reduce the altitude in which they fly.
Astronauts are asked not to go outside the space station
and sometimes actual satellites can be impacted.
Are coronal mass injections connected to the solar cycle?
The sun has spots.
The spots disappear and appear in a cycle of activity
that spans 11 years from minimum to minimum or maximum to maximum
and so we are currently coming out of the minimum
and we are moving into a region on a graph that looks
like we're kind of climbing a hill.
And at the top of that hill is what we call the maximum
of the sunspots cycle.
During the maximum there are many, many spots
and these spots are associated with a magnetic field.
The magnetic field can become twisted up,
kind of like a rubber band, and when you get enough energy
in that rubber band it will snap or it can snap.
That's called a solar flare.
How can we track what's going on with the sun?
You can actually look at spaceweather.com to find
out when this is going to happen.
There are also space weather alerts.
So that if you want to know
when a coronal mass ejection has occurred
and will be directed towards us, you'd be alerted
that it is happening and aurora might even be going on too.
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Our expert has created an activity just for you.
Check it out.
You and your classmates will use actual images of the sun
to determine the number of sunspots and their size.
Go the NASA Explorer Schools Virtual Campus
and see what you can find out about our sun.
Well that's it for NASA Now, be sure to check
out our Facebook page.
See you then on NASA Now.
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NASA Now comes to you from the Virtual Campus
at NASA Explorer Schools.