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SOHO and the Sun's Sonic Energy

By Brant David McLaughlin     Apr 19, 2008 in Science
“We see the plasma moving toward us, receding from us, moving toward us, receding from us...This large flare on the Sun, this disturbance, shakes the Sun and then it keeps vibrating for some time."
As observed by the European Space Agency/NASA jointly owned spacecraft named the Solar and Heliospheric Observatory (SOHO), powerful starquakes are being set off across the Sun when great solar flares explode above its surface.
Surface ripples that well up from the tempestuous and ever-oscillating stew of gas below the Sun's surface have been studied by SOHO in an attempt to deduce patterns that may be useful to scientists in predicting solar storms and coronal mass ejections, as well as the study of the nature of stars in general.
One class of the oscillations called the 5-minute oscillations, which have a frequency of about 3 millihertz, has proven particularly useful to these studies.
The SOHO observations have permitted astronomers to re-think their conceptualization of these 5-minute oscillations taking place within the “solar acoustic spectrum”.
Contrary to the conventional concept of these oscillations being like the sound produced by a bell placed in the middle of a desert and exposed to being struck by randomly-blown sand grains, "The signal we saw was like someone occasionally walking up to the bell and striking it, which told us that there was something missing from our understanding of how the Sun works,” says Christoffer Karoff of the University of Aarhus in Denmark.
In December of 2006, SOHO helped astronomers observe the direct effects of solar flare-driven space weather on Mars, Venus, and the Earth, allowing them to see that "flare activities on the far side of the Sun may affect terrestrial space weather as a result of traveling more than 90° in both azimuthal directions in the heliosphere", as stated by Dr. Yoshifumi Futaana.
Solar flares explode over and above the Sun’s surface and contain the explosive energy of tens of millions of hydrogen bombs. Their electromagnetic energy, especially if the flare remains focused (like the plasma content of a laser beam), can affect space-based instruments around and on the Earth and, over time, can have an effect on a planet’s atmosphere. Astronauts orbiting in space or working on the Moon could also be harmed by a powerful enough solar flare emission.
The theory that solar flares’ acoustic energy drives oscillations across the Sun’s surface was first conjured 36 years ago.
“We see the plasma moving toward us, receding from us, moving toward us, receding from us...This large flare on the Sun, this disturbance, shakes the Sun and then it keeps vibrating for some time with these global oscillations," says Bernhard Fleck, SOHO project scientist at NASA Goddard Space Flight Center in Greenbelt, Maryland
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