Monday, January 25, 2010

Jan. 25 - Mysterious band of particles holds clues to Solar System's future

Dear Friends,

http://www.cosmosmagazine.com/node/3251/full

Be Well.

David

Mysterious band of particles holds clues to Solar System's future

Monday, 25 January 2010

by Tony Phillips

Science@NASA

IBEX spacecraft's all-sky map reveals a bright ribbon of particles.

Credit: NASARelated articles

HUNTSVILLE, USA: The ribbon of particles at the edge of the Solar System "shocked" NASA researchers when it was discovered last year. Now they say it is a reflection off a strong galactic magnetic field, and holds the clues to the future of the Solar System.

In October last year, NASA's IBEX (Interstellar Boundary Explorer) spacecraft made the first all-sky maps of the heliosphere - the bubble of magnetism that springs from the Sun and surrounds our Solar System.

The result was a map bisected by a bright, winding ribbon of unknown origin. At the time, NASA researchers called it a "shocking result" and puzzled over its origin.

Unexplored territory

"We believe the ribbon is a reflection," says Jacob Heerikhuisen, a NASA Heliophysics Guest Investigator from the University of Alabama in Huntsville. "It is where solar wind particles heading out into interstellar space are reflected back into the solar system by a galactic magnetic field."

Heerikhuisen is the lead author of a paper reporting the results in the Astrophysical Journal Letters.

"This is an important finding," says Arik Posner, IBEX program scientist at NASA Headquarters. "Interstellar space just beyond the edge of the solar system is mostly unexplored territory.

"Now we know, there could be a strong, well-organised magnetic field sitting right on our doorstep."

Ribbon reveals vast magnetic field

The IBEX data fit in nicely with recent results from the Voyager spacecrafts. Voyager 1 and 2 are near the edge of the solar system and they also have sensed strong magnetism nearby.

The ribbon that IBEX sees is vast and stretches almost all the way across the sky, suggesting that the magnetic field behind it must be equally vast.

Although maps of the ribbon seem to show a luminous body, the ribbon emits no light. Instead, it makes itself known via particles called 'energetic neutral atoms' - mainly garden-variety hydrogen atoms. The ribbon emits these particles, which are picked up by IBEX in Earth orbit.

The reflection process posited by Heerikhuisen and his team involves multiple "charge exchange" reactions between protons and hydrogen atoms.

Particles escape from the Sun, forming what is called the 'solar wind'. As these particles escape the Solar System, approximately 100 astronomical units (or 15 billion km) away, they are met by an interstellar magnetic field.

Magnetic forces intercept the escaping particles and sling them right back where they came from.

"If this mechanism is correct - and not everyone agrees - then the shape of the ribbon is telling us a lot about the orientation of the magnetic field in our corner of the Milky Way galaxy," notes Heerikhuisen.

The Solar System's future

The Solar System is passing through a region of the Milky Way filled with cosmic rays and interstellar clouds. The magnetic field of our own sun, inflated by the solar wind into the bubble-like heliosphere, substantially protects us from these things. The heliosphere's size and shape are key factors in determining its shielding power and, thus, how many cosmic rays reach Earth.

However, the bubble itself is vulnerable to external fields. A strong magnetic field just outside the solar system could press against the heliosphere and interact with it in unknown ways. Scientists are unsure if this would this strengthen our natural shielding or weaken it.

"IBEX will monitor the ribbon closely in the months and years ahead," says Posner. "We could see the shape of the ribbon change—and that would show us how we are interacting with the galaxy beyond."

This is an edited version of a story first published on the Science@NASA web site.

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MUFON

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.

MUFON.COM