I remember Comet Kohoutek almost exactly 40 years ago to the month. It was visible, but basically a dud. We won’t know about Ison until she fizzles or explodes. Can’t say I hope for a spectacular show, because so much of humanity believes that such events portend megachanges. Not saying that I so believe, but if billions do so believe, that can severely affect the global psychology.
How do they predict if a comet will brighten up or not?