2001 SPACE SCIENCE VIDEOTAPES |
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Tape Title | Record ID |
Date Produced | TRT: |
Synopsis |
| A HIDDEN WORLD OF COMPLEXITY WITHIN THE SUN | G01-084 | 12/10/01 |
00:07:27 | Two new looks inside the Sun have shown
how large areas of stormy solar activity, called active regions, take
shape with a much more complex internal structure than previously
thought. Another study tracked and watched a sunspot that went for a
spin. This is all thanks to a sort of ultrasound instrument on the
Solar and Heliospheric Observatory (SOHO) that gives scientists a
special view through the surface of the Sun.
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TAPE CONTENTS: |
| ITEM (1): The Active
Region - In March 2001, an active region that also housed
sunspots, AR 9393, grew to a size 18 times larger than Earth. At
that size it became the largest active region harboring the largest
sunspot since 1991 and released record-setting flares into space and
toward Earth. Active regions are sites of fierce activity, generating
explosions called solar flares and eruptions of electrified and
magnetized gas (plasma) called Coronal Mass Ejections (CMEs).
Courtesy: NASA
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| ITEM (2): How Do Active
Regions Form? - Scientists know that the solar explosions
called flares are driven by distorted magnetic fields that suddenly
snap to a new, less energetic configuration, and that active regions
are sites of strong magnetic fields. By peering beneath the surface
of AR 9393, scientists found that such regions are comprised of many
small magnetic structures that rise quickly from deep within the Sun.
Other magnetic structures replenish these as they emerge, which makes
the active region, home to sunspots, grow.
Courtesy: NASA
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| ITEM (3): Spinning
Sunspots - Scientists used the August 2000 sunspot AR 9114 as
a model for studying spots that rotate. AR 9114 was an average-sized
spot that spun more than 200 degrees counter-clockwise in less than
three days. Scientists discovered a strong plasma vortex beneath the
rotating sunspot and that the magnetic fields lacing the sunspot
appeared to be twisted beneath the surface.
While scientists observed a plasma vortex beneath the sunspot, it is
unclear if the vortex twists the magnetic field or if the twisted
magnetic field somehow creates the vortex. This is a collaborative
view from SOHO & TRACE spacecraft.
Courtesy: NASA/ESA/LMSAL
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| ITEM (4): Why Study Active
Regions? - Discovering the cause of the twisted magnetic
fields within active regions is important because it might eventually
help predict stormy solar activity such as solar flares and coronal
mass ejections (CMEs), which can disrupt satellites, power and radio
systems on Earth. Here a CME leaves the Sun, bounces through the
Earth's magnetosphere and eventually reaches the poles in an aurora.
Courtesy: NASA
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| ITEM (5): Above The Active
Region - What is happening above the sunspot within the
active region? The Transition Region and Coronal Explorer (TRACE)
spacecraft caught these coils of hot, electrified gas, known as
coronal loops above active sunspots. The loops (some more than
300,000 miles high and capable of spanning 30 Earths) are comprised
of electrified gas that rises while flowing along the solar magnetic
field, then cools and crashes back to the surface at more than 60
miles per second (100 kilometers per second).
Courtesy: NASA/LMSAL
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| ITEM (6): X-RAY VISION OF
THE SUN
- Scientists analyzed sound-generated ripples on the
Sun's surface with a technique similar to a medical ultrasound.
Because sound travels faster in solar regions with a strong magnetic
field, they could construct a picture of the magnetic structures
inside the Sun. It was the Michelson Doppler Imager (MDI) instrument
on the Solar and Heliospheric Observatory (SOHO) that allowed the
study.
Courtesy: MDI/SOHO
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| ITEM (7): SOHO
SPACECRAFT - The Solar and Heliospheric Observatory (SOHO)
orbits the Sun at a location approximately one million miles from
Earth to gain an unobstructed view of the Sun. It carries 12
instruments including the Michelson Doppler Imager (MDI) and is a
joint NASA / European Space Agency (ESA) mission.
Courtesy: NASA/ESA
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| ITEM (8): TRACE
SPACECRAFT - NASA's Transition Region and Coronal Explorer
(TRACE) points its powerful telescope at the "transition region" of
the Sun's atmosphere, a highly volatile and dynamic region.
Sensitive to ultraviolet and extreme-ultraviolet wavelengths of
light, which are invisible to the human eye, scientists are given
dynamic views of solar explosions and coronal mass ejections (CMEs).
Courtesy: NASA/LMSAL
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