http://www.newsweek.com/asteroid-simulators-show-what-could-happen-earth-without-nasa-dart-1745880

As NASA's asteroid-deflecting DART mission approaches its target, simulators show what could happen to Earth in the event of an impact—and demonstrate the importance of research into planetary defense protocols.

On Monday, the DART (Double Asteroid Redirection Test) spacecraft is expected to deliberately crash into a 530-foot-wide asteroid called Dimorphos at a speed of nearly 15,000 miles per hour. The aim is to demonstrate that a spacecraft can deflect an object that could pose an impact threat to the Earth.