Just to illustrate the level of the nudges involved. The most dangerous currently known asteroid is Bennu, with 24 September 2182 as the most likely date of hi

Just to illustrate the level of the nudges involved. The most dangerous currently known asteroid is Bennu, with 24 September 2182 as the most likely date of hitting Earth. To do so, Bennu must pass through a gravitational "keyhole" on 25 September 2135. That keyhole is about 5 km wide. (To compare, the asteroid itself is about 0.5 km wide). It's like deflecting a projectile that shoots at a 5 km target from the distance of a couple hundred million km.