# Ison Comet

by Franco Malgari
Tags: comet, ison
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 P: 297 How often have we found "dynamically new comets" before this?
 PF Gold P: 771 I hope they're wrong. 'Comet of the Century' already may have fizzled out
 P: 7 Can someone show the results of a simulation that has a chunk exploding off of ISON such that it will encounter the sun around twenty degrees offset (counterclockwise) from the original path? This will direct the chunk into the plane of the ecliptic towards a rendezvous with Earth. The chunk could hit Earth if the velocity imparted to it would be around 1000 km/hr- provided the sun does not disintegrate it during perihelion. Your assignment- should you choose to accept it- would be to determine the velocities imparted to such a chunk at different times during its approach to the sun over the next two months or so. You can pick a single time in perhaps a month when solar radiation might be reasonably expected to heat the comet's internal water to create the pressure that might result in an explosion. The velocity would be at right angles to the path and heading north. Note that such a chunk will not be large enough to endanger a certain, extraordinarily destructive species living on the planet, but may give them pause to consider morphing from an infestation to a nurturing habitation. The odds are highly unlikely that anything will happen. But then again, the odds of 60-meter diameter asteroid accompanying 2012 DA14 was on the order of one out of a billion. Enjoy!
 P: 7 Answer: Turns out that the explosive force needed on the surface of ISON to send a chunk towards Earth is far beyond reasonable limits. At 1000km/hr, The chunk might achieve a separation of a million miles or more around Mercury's orbit, but at perigee when the comet is 30X closer to the sun, the separation distance will likewise be reduced by 30X. This will add less than a degree to the entrance path to perihelion for the chunk- not enough for the sun to whip the chunk down into the ecliptic towards Earth. Dang- another doomsday scenario discredited!
 PF Gold P: 1,496 Time for the ISON,I'll check it tonight,to see if it's visible to the Naked Eye. Nov 22nd.
 PF Gold P: 771 Getting closer. From today's APOD
PF Gold
P: 516
 Quote by Borg Getting closer. From today's APOD
Those are some pretty nifty wiggles in the tail of Comet Encke. Is it to be supposed that the current solar magnetic field reversal will accentuate the motions of the solar wind, and hence the motions of the comet tails?
 Sci Advisor PF Gold P: 2,667 The motions in the comets tail are primarily caused by fluctuations in the solar wind and by coronal mass ejections (which is what you are seeing in the above video clip - a CME)
PF Gold
P: 516
 Quote by davenn The motions in the comets tail are primarily caused by fluctuations in the solar wind and by coronal mass ejections (which is what you are seeing in the above video clip - a CME)
Ah ha, a CME! This blog of Karl Battams has a 2007 video of 2P/Encke's tail being completely ripped off by a CME. http://www.isoncampaign.org/karl/comets-in-solar-wind

His colleagues say the stronger magnetic field of the CME caused the tail to reconnect from the IMF.

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