What can be done?
Within decades, the world’s leaders may be faced with a dilemma: what to do about an incoming object. Few experts are giving this much thought, according to NASA astronomer David Morrison “The number would roughly staff a couple of shifts at McDonalds,” he says ED Lu, the former astronaut, is one of them. He is working on a plan that employs a spaceship to deflect asteroids headed for Earth. “WE were originally thinking about how you would land on an asteroid and push it, “he says. “But that doesn’t work well.” If the surface isn’t solid, you have trouble landing or keeping anything on it. Moreover, asteroids are always rotating, the pushing just cancels out,” Lu say
Pulling the asteroid along would be much easier, “Rather than having a physical line between you and the thing you’re toeing, you’re just using the force of gravity between them,” Lu say. A nearby spacecraft would pull the asteroid off course very slowly but steadily, using only gravity. And over the long distances of space, just a slight change in course could mean missing Earth by tens of thousands of kilometers.