Comet Ison

[mick]

Looks like it, I was just looking at this video.

http://vimeo.com/80581759

[ButterflyWoman]

And now NASA is saying, well, maybe it's NOT dead....

http://abcnews.go.com/Technology/com...ry?id=21053068

This is the most interesting comet saga I've ever followed!

[-asalantu-]

http://vimeo.com/80581759

AquÃ♥ hay algo raro. La cola (ó cabellera) del cometa, acostumbra apuntar en dirección opuesta al Sol en razón de que es una proyección debida a los hielos evaporados impulsados por el viento solar. No es lo que se aprecia en los fotogramas.

Atentamente...
�ngel

Translation:
Here's something strange. The tail (or plume) of the comet usually points in the opposite direction to the sun because it's projected by the evaporating ice blown away by the solar wind. It's not what appears in the frames.

[mick]

And now NASA is saying, well, maybe it's NOT dead....

http://abcnews.go.com/Technology/com...ry?id=21053068

This is the most interesting comet saga I've ever followed!

Quite, the SOHO video shows that it apparently did lose its shine when having its close encounter but the SDO data are in conflict with expectations and go on to say that the behaviour of this comet has been confounding them all from the start. NASA and ESA et al are busily looking to see if there are any large lumps remaining. In the other camp, the Electric Universe people make the statements that its behaviour is consistent with their hypothesis.

[eyeoneblack]

Quite, the SOHO video shows that it apparently did lose its shine when having its close encounter but the SDO data are in conflict with expectations and go on to say that the behaviour of this comet has been confounding them all from the start. NASA and ESA et al are busily looking to see if there are any large lumps remaining. In the other camp, the Electric Universe people make the statements that its behaviour is consistent with their hypothesis.

Umm, what are the Electric Universe people? Their hypothesis?

[ok, I googled it. It is a seductive idea.]

[mick]

http://vimeo.com/80581759

Google: Here's something weird. The tail (or hair) of the comet, usually point away from the Sun because it is a projection due to the ice evaporated driven by the solar wind. It is what is shown in the frames.
�ngel

I noted that, it may be something to do with the viewing perspective, SOHO is in a somewhat similar plane to that of the Earth whereas the orbit of the Comet is somewhat angled to the solar ecliptic (image from http://www.solarsystemscope.com/ison/. Just guessing here but maybe the explanation.

[eyeoneblack]

The comet's tail is always in line with the solar wind. So, if the comet were in just the right alignment to the sight of Earth such that it pointed directly at us, the comet would virtually disappear from our sight. Si?

[-asalantu-]

That's right, eyeoneblack. If the three (observator, comet and Sun), were aligned, then, from observator viewpoint comet would apparently dissapear. Solar wind, would drive comet tail (a.k.a. comet hair [cabellera del cometa]) directly to us.

But, the real scenaryo is sustantially more complex. Done high UV' and X' ray flux, tail particles are highly ionized and done high magnetic field strenght near Sun, particle behaviour are drive through following mathematical relation:

F = qV x B

where:
F (is the force [vector] exerted over ionized particle)
q (is particle charge)
V (is particle velocity [another vector])
B (is magnetic field intensity [another vector])
x (denotes product is vectorial)

Furthermore, you must add momentum exchange between proton flux through collision with ionized particles.

So, if you wants to catch on the complexity of such calcul google with keywords:

"Lorentz's Force" and "Vectorial Product"

A little headache...

My best regards,
�ngel