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(meteorobs) An astronomic-al anomaly
Please pardon the off topic subject. I just had to share, due to its rarity of circumstance.
- Christine
http://www.astronomy.com/Content/Dynamic/Articles/000/000/001/546dshgp.asp
Cassini listens to solar storm
NASA's Cassini spacecraft records the sound of a huge solar outburst.
by Vanessa Thomas
The radio burst recorded by Cassini on October 28, 2003, quickly dropped in pitch.
Donald Gurnett / University of Iowa
Click on this image to listen to a radio burst caused by electrons emitted in a large solar flare on October 28, 2003.
audio courtesy of Donald Gurnett / Univ. of Iowa
About 19 hours after one of the largest solar flares seen in decades burst from the sun on Tuesday, October 28, sky watchers as far south as Texas began witnessing beautiful streams of colored aurora dancing in the northern skies. But just 69 minutes after the eruption, the Cassini spacecraft, currently located 8.7 astronomical units (AU) from Earth, tuned into radio waves emitted by a swarm of electrons ejected from the sun during its brilliant outburst.
"This is one of the biggest events of its kind ever seen," says University of Iowa physicist Donald Gurnett, principal investigator for Cassini's Radio and Plasma Wave Science instrument, which recorded the natural music performed by the solar storm. "The sound is produced by electrons moving out from the solar flare, beginning at a high frequency before dropping to a lower frequency," Gurnett explains.
The recording seems like a sound effect from a sci-fi movie. A synthetic, falsetto tone swells suddenly and then gradually drops, recreating the sound a sleek alien vessel might make if it glided overhead and then flew away into the distance.
The Cassini spacecraft is currently traveling to Saturn and is due to arrive at its destination in July 2004. During its travels, the Radio and Plasma Wave Science instrument monitors electric and magnetic waves in the thin gas of charged particles sprinkled among the planets. At Saturn, the instrument will measure electron densities and temperatures near the large moon Titan and in some parts of Saturn's magnetosphere. The radio frequencies it records are converted to sound waves so Gurnett and his colleagues can listen for patterns.
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http://www.astronomy.com/Content/Dynamic/Articles/000/000/001/544panrz.asp
Thank you Sun, may I have another?
The Sun directs one outburst after another our way, producing extensive auroral displays and causing minor technological inconveniences.
by Matt Quandt
A powerful X11 solar flare erupted at 3:48 p.m. EST on October 29, 2003.
SOHO / NASA / ESA
This week will go down as one of the most historic in documented solar activity. At 5:54 a.m. on October 28, 2003, the third most-powerful solar flare ever recorded erupted from sunspot 486 and launched a powerful coronal mass ejection (CME) toward Earth. The CME fired electrically charged gas toward us at a speed of more than 2,000 kilometers per hour (1,250 miles per hour).
Earth had a front-row seat for this epic performance. The category-X17.2 solar flare was aimed directly at us. X rays from the flare, traveling at the speed of light, bombarded Earth’s ionosphere, causing a radio storm. Such immense flares have the potential to interfere and wreak havoc on power grids and satellite operations. Bracing for the storm, power companies reduced their line leads to allow leeway for possible surges.
As people on Earth braced for the class-5 geomagnetic storm, the Sun shot off an encore performance. Although not as powerful and slightly less dramatic than Tuesday’s X17.2, Wednesday’s X11 flare certainly didn’t leave the audience of scientists and space-weather forecasters disappointed. Rather, the two huge flares, both originating from sunspot 486 — a sunspot bigger than Jupiter — left even the most experienced solar scientist impressed.
Auroral activity appeared farther south than normal in the last week of October 2003.
NOAA Space Environment Center
A green-trimmed sheet of red aurora hangs over Park City, Utah.
Anthony Arrigo
“I have not seen anything like it in my entire career as a solar physicist. The probability of this happening is so low that it is a statistical anomaly,” says John Kohl, a solar astrophysicist at the Harvard Smithsonian Center for Astrophysics and principal investigator for the Ultraviolet Coronagraph Spectrometer on board NASA’s Solar and Heliosperic Observatory (SOHO) spacecraft.
“The Sun is really churned up," Kohl adds. "The timing of two very large X-class flares aimed directly at Earth, occurring one right after another, is unprecedented.”
Thus far, the effects of these two storms have passed with little consequence. Planes continue to fly on schedule and without newsworthy complications. According to some reports, airplanes flying in extreme northern latitudes have had minor problems with radio communications, but no flights have been stopped.
These historic and immense solar flares have, instead of tragedy, produced expansive beauty. The two huge geomagnetic storms created by the solar flares occurred between October 29 and October 30, generating widespread auroral displays. According to plots on the Space Environment Center’s Auroral Activity web site, aurora activity was detected as far south as Alabama, and some report spotting it in Texas. Aurorae twinkled farther south in the night skies of Europe, Asia, and North America than usual, giving people who are normally too far removed from the poles a chance to bask in the aurora’s emerald and crimson veils.