CrimsonEagle
Padawan Learner
"For several days around January 12, 2014, Earth will pass through a stream of fine-grained debris from Comet ISON," says Wiegert. "The resulting shower could have some interesting properties.
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According to Wiegert's computer models, the debris stream is populated with extremely tiny grains of dust, no more than a few microns wide, pushed toward Earth by the gentle radiation pressure of the sun. They will be hitting at a speed of 56 km/s or 125,000 mph. Because the particles are so small, Earth’s upper atmosphere will rapidly slow them to a stop.
"Instead of burning up in a flash of light, they will drift gently down to the Earth below," he says.
Don’t expect to notice. The invisible rain of comet dust, if it occurs, would be very slow. It can take months or even years for fine dust to settle out of the high atmosphere.
http://science.nasa.gov/science-news/science-at-nasa/2013/19apr_isonids/
Of course, we will not know until, or even it it will happen, but I can not help but wonder if it is the time of a new plague.