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Narrator: Hello, I'm Nicholeen Viall, and I'm
a solar physicist at NASA's Goddard Space Flight Center.
What we're looking at right now is imagery from the Solar Dynamics Observatory.
All of the dynamics and activty that's going on in the
solar corona, the sun's atmosphere, which is what I study.
What we're seeing here is a filament and it looks very
dark and it looks like it's actually maybe even on the surface of the sun.
But we can see as the sun rotates around that actually it's
suspended high up in the atmosphere, away from the surface. When viewed from
this angle, we call them prominences. This material is
held up in the corona by twisted magnetic fields
We're looking at the solar corona in extreme ultraviolet
at 171 Angstroms, which is a wavelength that our
eyes cannot see. My favorite thing is all of these
magnetic loops that you can see on the sun, how dynamic
these magnetic loops are, just telling us how much change
and evolution and activity there is on the sun at all scales.
We can see on the northern part
of the sun that a prominence rotates onto the disk of the sun
and then it erupts in a giant coronal mass ejection, and
all of that magnetic energy and all of the plasma that was trapped on those magnetic field
lines launches out into the solar system.
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We're watching the sun rotate right now, this is one of the basic features of the sun, and
it takes about a month for sun to rotate fully around and to see the
same spot on the sun come back. We're seeing the sun
rotate so quickly in this movie because it's timelapsed.
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When the sun jumps around, that's actually
the Solar Dynamics Observatory moving around and pointing
different directions. Sometimes they have to point away from the sun so
that they can calibrate their sensors, the cameras.
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When we see the frames go dark, that's eclipse
season, so that's when the Solar Dynamics Observatory, which is orbiting the Earth,
goes behind the Earth, and the Earth is between the Solar
Dynamics Observatory and the sun, and so the Earth eclipses the images.
These really bright spots, called
active regions, have concentrated magnetic field and
concentrated heating because of this extra magnetic field and the extra energy
due to it. There are more active regions during solar maximum,
and fewer active regions during solar minimum. And often these active regions
can lead to solar eruptions such as solar flares and
coronal mass ejections.
I study the coronal heating problem. That is why
the solar corona so much hotter than the solar surface below it.
And we know that it has to do with the magnetic field, which is
constantly dynamic and evolving and injecting
energy into the solar corona, and you can really get a sense of that when you
watch these Solar Dynamics Observatory movies.
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