New means of deflecting course of dangerous asteroids

Proposals for deflecting NEAs have included blasting them with nuclear explosives, tugging them with nuclear-powered spacecraft or painting them white on one side so that reflected solar energy will nudge the asteroid off course. Blowing up the asteroid could leave vast fragments still Earthbound, however, and tugging and painting can only push the asteroid a few kilometres off course, says Fargion.

He proposes an alternative, inspired by the way rockets are propelled forward as they eject mass when burning fuel. He suggests dropping nuclear-powered rockets, each tipped with a screw-shaped drill, onto the asteroid from a mother ship. After latching onto the asteroid’s surface - not easy in almost zero gravity - each “screw rocket” will drill deep into the asteroid, projecting the rocky spoil behind it into space at high speed and pushing the asteroid off course. More...