Science?

Watching the National Geographic Channel's "The Known Universe". Now I'm no scientist, so perhaps someone can correct me, but I'm quite sure that the following is not particularly scientific:

- "If an asteroid were to come near us, you might as well bend over, grab your ankles and kiss your ass goodbye" - speaking in purely 'scientific' terms here.....

- "There are a million, or a billion, asteroids out there" - they are clearly completely confident with their calculation here to limit the wiggle room between their numbers.

- "If you had a time machine......" - this appears to be the beginning to many scientific hypothesis'

- "The last time earth faced this threat was 65 million years ago. Does that mean you should lay awake at night worrying? Well its enough to say it happened once, it can happen again" - get in your bunkers! hide your children! SAVE YOURSELVES

- "How will we save ourselves from an asteroid? Former astronaut 'Rusty' thinks he has the answer....a gravity tractor" - thank god we have 'Rusty' working for us.

-"This is called a 'gamaray-burst', doesn't sound particularly scary, but its one of the few things in the universe that gives me the heeby-geebies" - heeby-geeby is a scientific measurement, much the same as 'millions or billions'.

- "If this acrylic ball is earth, and this smaller ball is an asteroid, and we shoot the smaller one from a high powered machine at the larger one, we can assume that the impact would be the equivilant of a larger object traveling at a slower speed" - i...don't understand science, obviously.