I don't mean to be an End of Days Alarmist or anything but what happens if it goes off course by a few feet ???
On April 13, 2029, a 1,110-foot-wide asteroid known as 99942 Apophis will speed past our planet at an estimated distance of around 19,000 miles, potentially coming closer to the surface than some orbiting spacecraft ....
News: http://www.msn.com/en-ca/news/world/god-of-chaos-asteroid-apophis-is-headed-for-earth
"Apophis is a representative of about 2,000 currently known Potentially Hazardous Asteroids (PHAs)," Paul Chodas, director of CNEOS, said in a statement. "By observing Apophis during its 2029 flyby, we will gain important scientific knowledge that could one day be used for planetary defense."