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Thursday, March 18, 2010

March 18 - Solar storms create 'killer electrons'‏

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Be Well.


Solar storms create 'killer electrons'

Thursday, 18 March 2010

by Heather Catchpole

Cosmos Online

Solar storm

A stream of charged particles from the Sun hits Earth's magnetosphere.

Credit: NASA

SYDNEY: 'Killer electrons' - electrons circling Earth that wreck satellites and can cause cancer in astronauts - are created when Solar storms create shockwaves in the Earth's protective magnetic bubble, scientists said.

The Earth's magnetic field abounds with charged, fast moving particles that orbit up to 64,000 km above the surface. When a severe solar storm - a stream of energetic particles emanating from the Sun - hits the Earth's magnetic field, it creates a shockwave that boosts the number of particles by up to ten times as much.

These highly energetic negative particles, which scientists have dubbed 'killer' electrons, can penetrate satellites and spacecraft and cause miniature lightning storms within the electronics. They also pose a health risk to astronauts.

Particle energy amplified

Until now, scientists were unsure what was causing the electrons to accelerate to such high speeds. An international team led by space physicist Qiugang Zong from Peking University in China and the University of Massachusetts Lowell in the U.S. says waves within the magnetic field itself amplify the energy of the particles to the point where they become a serious hazard.

As the waves travel through Earth's magnetic field, it causes the charged particles to accelerate - first in one direction, then in the opposite direction.

Because the particles are oscillating in phase with the waves they begin to speed up - this is like sloshing back and forth in the bath in time with the reflected waves, causing them to get bigger.

Different frequencies accelerate electrons

"A killer electron storm is the most dangerous phenomena in the space environment," Zong said. When these storms occur, satellites should be switched to safe mode or turned off, launches delayed and astronauts should avoid spacewalks, he said.

The researchers used data from the European Space Agency's four Cluster satellites on two solar storm events, a big one in November 2004 and another, smaller event in 2001.

They then analysed the data to examine the role played by different frequency 'pulses' in the magnetic field, including two sets of waves: ultra low frequency waves (ULF, 0.001-1 Hertz waves) and very low frequency waves (VLF waves, 3-30 kHz). The results were published last year in the Journal of Geophysical Research.

While the VLF waves accelerate the particles over longer timescales, it is the lower frequency ULF waves that give the initial kick start, says Zong.

Space weather scientist Murray Parkinson, from the IPS Radio and Space Services at the Bureau of Meteorology in Sydney likened the effect to a ringing bell.

Shockwaves around Earth

A bell hit by a rod rings with soundwaves. Similarly, as the shockwave from the solar storm hits the Earth's magnetosphere, the pressure rises and the system begins to 'ring' with these ultra low frequency waves.

The ULF waves cause the particles to accelerate back and forth, and you would expect there would be no net acceleration, he says.

"But there are certain resonances where particles are drifting in phase with the waves and it produces a net acceleration," he says. The VLF waves continue this acceleration, but on a longer timescale.

"There's been a question mark about the physics that leads to the acceleration of these particles and how they are boosted to these lethal relativistic energies," he says. "We've lost many spacecraft due to hazardous radiation environments - I think this is quite a significant result."


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How to Digitally Record/Video a UFO sighting:

Como registar digitalmente ou gravar um vídeo de um avistamento de um UFO:

Stabilize the camera on a tripod. If there is no tripod, then set it on top of a stable, flat surface. If that is not possible lean against a wall to stabilize your body and prevent the camera from filming in a shaky, unsteady manner.

Estabilize a camera com um tripé. Se não tiver um tripé, então coloque-a em cima de uma superfície estável. Se não for possível, então encoste-se a uma parede para estabilizar o corpo e evitar que a camera registe de maneira tremida e instável.

Provide visual reference points for comparison. This includes the horizon, treetops, lampposts, houses, and geographical landmarks (i.e., Horsetooth Reservoir, Mt. Adams, etc.) Provide this in the video whenever is appropriate and doesn’t detract from what your focus is, the UFO.

Forneça pontos visuais de referência para comparação. Isso inclui o horizonte, cimo das árvores, postes de iluminação, pontos de referência geográficos (como o Reservatório de Horsetooth, Mone Adams, etc) Forneça esses pontos no vídeo sempre que for apropriado e não se distraia do que é o seu foco, o UFO/a Nave.

Narrate your videotape. Provide details of the date, time, location, and direction (N,S,E,W) you are looking in. Provide your observations on the weather, including approximate temperature, windspeed, any visible cloud cover or noticeable weather anomalies or events. Narrate on the shape, size, color, movements, approximate altitude of the UFO, etc and what it appears to be doing. Also include any unusual physical, psychological or emotional sensations you might have. Narrate any visual reference points on camera so they correlate with what the viewer will see, and thereby will be better able to understand.

Faça a narração do vídeo. Forneça pormenores sobre a data, hora, local e direcção (Norte, Sul, Este, Oeste) que está a observar. Faça observações sobre as condições atmosféricas, incluindo a temperatura aproximada, velocidade do vento, quantidade de nuvens, anomalias ou acontecimentos meteorológicos evidentes. Descreva a forma, o tamanho, a cor, os movimentos, a altitude aproximada onde se encontra o UFO/nave, etc e o que aparenta estar a fazer. Inclua também quaisquer aspectos pouco habituais de sensações físicas, psicológicas ou emocionais que possa ter. Faça a narração de todos os pontos de referência visual que o espectador irá ver e que, deste modo, será capaz de compreender melhor.

Be persistent and consistent. Return to the scene to videotape and record at this same location. If you have been successful once, the UFO sightings may be occurring in this region regularly, perhaps for specific reasons unknown, and you may be successful again. You may also wish to return to the same location at a different time of day (daylight hours) for better orientation and reference. Film just a minute or two under “normal” circumstances for comparison. Write down what you remember immediately after. As soon as you are done recording the experience/event, immediately write down your impressions, memories, thoughts, emotions, etc. so it is on the record in writing. If there were other witnesses, have them independently record their own impressions, thoughts, etc. Include in this exercise any drawings, sketches, or diagrams. Make sure you date and sign your documentation.

Seja persistente e não contraditório. Volte ao local da cena e registe o mesmo local. Se foi bem sucedido uma vez, pode ser que nessa região ocorram avistamentos de UFOs/naves com regularidade, talvez por razões específicas desconhecidas, e talvez possa ser novamente bem sucedido. Pode também desejar voltar ao mesmo lugar a horas diferentes do dia (durante as horas de luz)para ter uma orientação e referência melhor. Filme apenas um ,inuto ou dois em circunstâncias “normais” para ter um termo de comparação. Escreva tudo o que viu imediatamente após o acontecimento. Logo após ter feito o registo da experiência/acontecimento, escreva imediatamente as impressões, memórias, pensamentos, emoções, etc para que fiquem registadas por escrito. Se houver outras testemunhas, peça-lhes para registar independentemente as suas próprias impressões, pensamentos, etc. Inclua quaisquer desenhos, esbolos, diagramas. Certifique-se que data e assina o seu documento/testemunho.

Always be prepared. Have a digital camera or better yet a video camera with you, charged and ready to go, at all times. Make sure you know how to use your camera (and your cell phone video/photo camera) quickly and properly. These events can occur suddenly, unexpectedly, and often quite randomly, so you will need to be prepared.

Esteja sempre preparado, Tenha sempre uma camera digital, melhor ainda, uma camera vídeo consigo, carregada e pronta a usar sempre que necessário. Certifique-se que sabe como lidar com a sua camera (ou com o seu celular/camera fotográfica) rápida e adequadamente. Esses acontecimentos podem acontecer súbita e inesperadamente e, por vezes, acidentalmente, por isso, necessita estar preparado.

Look up. Be prepared. Report. Share.

Olhe para cima, Esteja preparado, Relate, Partilhe.



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