The collision could wipe out a country the size of England the article says.
Things like hitting them with a bomb or flying a spacecraft into them - you just do not know what the results of that are going to be." Scientists now favour deploying so-called 'Gravity Tractors', small spacecrafts that would travel close to a speeding asteroid and, with their own gravitational pull, try to drag it onto a different path.
It is just 2007, less than 29 years. There is simply not enough time for UN to make a decision.