Deflected asteroids may keep coming back 17 November 2007 What goes around comes around. Unfortunately, no such karma figures in plans to deflect asteroids on a collision course with Earth, a hearing of the US House Science and Technology Committee was told last week. One big whack will deflect an asteroid temporarily, but does not guarantee safety next time its orbit brings it close. Asteroid researchers have long debated the merits of deflecting asteroids with a powerful blast such as a nuclear explosion. However, Rusty Schweickart, who heads an asteroid research group called the B612 Foundation, told the committee that...