Asteroids collidable with Earth

[Mica]

Scientists are on idea to avoid the collision of asteroids with the Earth. B4 clearing up the matter, let me discuss with u all, how the asteroid-collision can destroy the earth surface / life on it.

Diameter of the asteroid ------Destruction it can cause

10 yards -----------------Destructiv in populated areas
60 yards -----------------Destroys a city; Ocean strike causes massive tidal wave
150 yards ----------------Devastate a small country
1 mile --------------------Expected to hit earth every few hundred years; can wipe out an entire continent
10 miles ------------------Global killer like which destroyed the dinosaurs


According to the journal from which i got this info, there is going to be some spacecrafts which will be launched in an intercept course. Robotic spacecrafts will be landed on asteriod surfaces, the arms of which will anchor it to the surface; some will drill down thru - pulling out mass in form of dust/debris. This mass ejection will make the asteroid alter it's course.