Interesting. It reminded me of accounts I read about Halley's comets return in 1910 (not *real* time of course - even *I* wasn't born then!!
) People apparently got very worried about the effects of breathing in the comets gases, and some charlatans were able to sell "anti-comet" masks and the like. I haven't done an exhaustive search for this because of time constraints, but found this:
"Is there any danger from Comet Halley?
Before we understood the nature and orbits of comets, people worried about the effects a comet might have on us. Today we know enough about these objects to provide a reassuring "environmental impact statement.'' Unless a comet physically collides with the Earth (which Halley will be far from doing), these small chunks of dirty ice pose no danger to us. Their effects are on the mind, stimulating our curiosity and kindling our imaginations."
from here
As for meteorites posing a threat - well, yes, every day there is a likelihood of something impacting with the Earth (which is what "shooting stars" are after all, as this cosmic debris "burns up" in the atmosphere), so it is not inconceivable... All we can say is that so far, we've been very lucky that we've avoided the "big one" in recent years - unless you include Tunguska, of course... here
