Imagine that Nasa discovers an asteroid that may be headed to earth in about 20 years, but they are not sure, so they just keep an eye on it.
Next thing you know, Nasa reports that they have discovered that the asteroid is heading toward earth. The check and double check, and sure enough, it is one its way, and headed strait for the US.
So, the government puts together a crash coarse program costing billions of dollars to make an attempt to stop the asteroid before it hits earth.
FInally, the new systemns are in place, and the attack on the asteroid is launched. It is a great success. It was stopped in time, however, many smaller pices will be hitting earth as a result of the action to stop it, and hundreds will still die, maybe even thousands, but that is a small price to pay for the saving of millions of lives.
Now, lets go forward about 5 years. The event is being looked at and restudied to find better ways of defending ouesleves in the future, when it is discovered that the data was wrong that NASA origianlly had, and it is found out that if we had simply done nothing, and not acted agaisnt the threat, the asteroid would have not hit earth.
Would we have been wrong is doing what we did?
