It is important for NASA to monitor asteroids near earth because if they did not and one crashed in to earth we would have had no warning.

This is awesome. I love back to the future.

It is important because they would have to warn and the people would have to prepare. If there was a hurricane coming to your part of the country and you had no clue about it beforehand, would you like to be given some sort of warning? Would you like some time to get ready or do something that could possibly save your life instead of being hit on the spot? I would think so. I believe the same applies to the asteroids.

I would use the lnvisablity cloak use it to save people.

Very thoughtful. Great comment!

If any body has read War of the Worlds or has simply done a science experiment (I know those are two very different things, but trust me, they connect) then you would know that if you even change the tiniest thing in any of the variables, you'll know that the result will conclude differently. I think that if any microbes from Earth came i contact with alien life that it would definitely change the outcome had it not. So, I think maybe observing before we jump to see what is going on is most likely a better option.