Every American should be FORCED to watch Bill Nye The Science Guy.  These updates are somewhat skewed towards kids, but he never insults their intelligence and that makes them perfect for adults too.

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I've thought about the whole "comet streaking towards earth" thing myself. It seems like we could just "blast" it out of the sky. Well the first thing that morons like me don't realize, is that these things are REALLY BIG.  So, as you'll learn if take time to watch this little video, you don't necessary have to try to explode a comet into a bazillion pieces, there's other things that could be done (in theory). Check it out: