10-26-2013, 04:17 PM
Well, Paul, it's happened before! I'm not sure panic is the right word, but comets often bring some fringe groups out into the public eye. Back to that in a second, but we do know of comets breaking up due to close encounters. Comet Shoemaker-Levy 9, the one that famously collided with Jupiter back in the 1990s, broke up into several pieces, although that was due to a close encounter with Jupiter rather than the sun. Other comets have broken up as well (e.g., 73P/Schwassmann–Wachmann but over a period of many years in the 1990s and early 2000s). Current thinking seems to lean towards ISON surviving its close encounter with the sun, but we won't know until December.
As to the panic/fringe groups thing, I think that video SBH posted a link to is an example of that (sorry, SBH, I'm not at all accusing you of belonging to a fringe group!). I'm rather sceptical that video is real. First, I've never heard of the "Chinese Space Radar" and secondly that's not a radar image and almost certainly couldn't be one. The date it was taken was supposedly 3rd September this year. Comet ISON was a little less than 300 million miles away from Earth at that point. The comet's nucleus is believed to be around 3 miles in diameter. That would mean the nucleus would appear to be 2 milliarcseconds across to someone observing it from Earth. There is absolutely no way any radar or telescope could resolve the nucleus let alone produce an image shown in that video.
As to the panic/fringe groups thing, I think that video SBH posted a link to is an example of that (sorry, SBH, I'm not at all accusing you of belonging to a fringe group!). I'm rather sceptical that video is real. First, I've never heard of the "Chinese Space Radar" and secondly that's not a radar image and almost certainly couldn't be one. The date it was taken was supposedly 3rd September this year. Comet ISON was a little less than 300 million miles away from Earth at that point. The comet's nucleus is believed to be around 3 miles in diameter. That would mean the nucleus would appear to be 2 milliarcseconds across to someone observing it from Earth. There is absolutely no way any radar or telescope could resolve the nucleus let alone produce an image shown in that video.