Awwwww.... it missed.
I don't actually believe that "they" would make it known to the public if an earth-shattering (so to speak) one was on course to make contact with earth. Can you imagine the panic and freaking out that would take place? Too much advance notice would be a mistake.
An hour or so heads-up would be cool though. Enough time to make a final fabulous drink or two or three and stake out a good place to sit and watch for the final flash.
