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Heavy earth moving equipment

00:00 Mon 12th Feb 2001 |

by Lisa Cardy

IN A�billion years or so the Sun will have become so bright that we will be fried to oblivion. But scientists have come up with an alarmingly simple solution to save planet Earth; move it.

Just how are the scientists proposing such a move could be brought about By using the well-understood 'gravitational sling shot' technique often used to give space probes an extra boost on their way to the outer planets. The researchers claim that by using the energy of a large asteroid forced to pass by our planet, Earth could be repositioned into a larger orbit and so maintain our climate. The planetary manoeuvre could more than double the time life can survive on our planet. It could even allow our descendants to alter our Solar System to move moons and planets to make new Earths.

The astonishing idea has been put forward by Don Korycansky, of the University of California, along with Gregory Laughlin, of the US space Agency Nasa, and Fred Adams, of the University of Michigan.

The slingshot effect works when two objects�'bounce off' each other, although of course the Earth and an asteroid wouldn't really touch.

Imagine if you threw a ball at a wall, it bounces back to you at the original speed with which you threw it. But if the wall is moving towards you, at say 20 miles an hour (mph), then the ball moves towards the wall at the original speed with which you threw it, say 5 mph, plus the 20 mph that the wall is travelling at. It therefore returns toward you at the 25 miles per hour with respect to the moving wall plus the 20 mph at which the wall is coming at you. Hence, it picks up twice the speed of the moving wall.

A gravitational interaction with an asteroid is just like bouncing off it, its energy is transferred to Earth, giving it a boost to move it into a larger orbit.

According to the researchers there's lots of time to pick a suitable asteroid and develop the necessary technology to deflect the giant rock in the direction of Earth. The manoeuvre would need to be repeated every 6,000 years or so to keep up with the Suns increasing brightness.

Now you understand how scientists are planning to move Earth, you can ask The AnswerBank for an explanation of any other scientific method just by clicking here.

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