Well then, Stan: It's up to you to find these things, with enough warning that humanity (which, of course, means the Untied States of America) can do something about it.
For a long time I had a NASA artist's depiction of a (very large) asteroid hitting the earth as my my wallpaper on the computer. Quite the image.
Emergency Medicine - saving the world from themselves, one at a time. "Thou shalt not be a victim, thou shalt not be a perpetrator, but, above all, thou shalt not be a bystander." I make the ADL soil themselves. And that makes me very happy 
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