2004 SPACE SCIENCE VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| FIRST 3D VIEW OF SOLAR ERUPTIONS | G04-033 | 6/30/04 | 6:14 | Massive solar eruptions called coronal mass ejections (CMEs) are among the most important events in space for scientists to understand. When directed at Earth, CMEs can disrupt radio communications, satellites, and power grids. While we have satellites in space and observatories on the ground to track these CMEs, scientists can now image them in three-dimensions (3D). The new views are created from ordinary two-dimensional images from the SOHO spacecraft.
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TAPE CONTENTS: |
| ITEM (1): Three-Dimensional View - Seeing the structure of CMEs in three dimensions helps scientists understand the origin and processes that launch the billion-ton explosions of plasma into space and sometimes toward Earth. The magnetic fields that generate CMEs are invisible, but because the CME gas is electrified (plasma), it spirals around the field, tracing out its shape. Seeing the CME gas in 3D provides even more information on the structure and behavior of the fields powering the events in the first place.
Courtesy: NASA/ESA
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| ITEM (2): What is a CME? - The largest explosions in the solar system, CMEs launch up to 10 billion tons of electrified gas into space at speeds of one to two million miles an hour. They can cause magnetic storms by interacting with the Earth's magnetic field, distorting its shape and accelerating electrically charged particles trapped within. Researchers believe CMEs are launched when solar magnetic fields become strained and suddenly "snap" to a new configuration, like a rubber band that has been twisted to the breaking point. Courtesy: NASA
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| ITEM (3): From Flare to a CME (multi-mission) - This visualization marries images from five instruments on three separate satellites to show everything from a flare in extreme closeup to a series of associated CMEs. The researchers imaged both halo and loop CMEs, defined by the perspective of the viewer. Loop CMEs provide a side view of an eruption, while halo CMEs are seen from a front or rear view. Flares get their energy from the destruction of magnetic fields in the Sun's atmosphere, which can't repeat in exactly the same way.
Courtesy: NASA / ESA / LMSAL
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| ITEM (4): A SOHO Perspective (LASCO) - The Large Angle Spectrometric Coronograph (LASCO) instrument on SOHO takes images of the solar corona (outer atmosphere) by blocking the Sun like a total solar eclipse. CMEs can be seen being expelled away from the Sun and crossing the fields of view of the two coronagraphs. In this October 28 solar event, the C2 imager shows the inner corona extending up to 8.4 million km (5.25 million miles) from the Sun and the C3 imager extends 45 million km (30 million miles from the Sun, almost the distance between Mercury and the Sun.
Courtesy: NASA/ESA
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| ITEM (5): SOHO Spacecraft - NASA scientists measured the ratio of polarized to unpolarized light from coronal emissions taken by the LASCO instrument on the Solar and Heliospheric Observatory (SOHO) spacecraft. They then combined the polarization data with the total brightness data to reconstruct the CME in three dimensions. Light has three properties: brightness, color and polarization. Light which has an electric field oriented randomly in all directions is unpolarized, while light with an electric field oriented in just one direction is polarized.
Courtesy: NASA/ESA
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