Could a "Tractor Beam" save Earth?

[C1ay]

Two NASA astronauts have figured out a way to create a real-life version of a "Star Wars" "tractor beam" to keep an asteroid from crashing into Earth.

 

By hovering nearby for perhaps a year, the astronauts say, the spacecraft's own gravity could minutely slow the asteroid's progress or speed it up, a process that 10 or 20 years later would cause the rogue rock to miss Earth by a comfortable margin.

 

"The beauty of this idea is that it's incredibly simple," said astrophysicist-astronaut Edward Lu. Since momentum does not dissipate in space, with enough time only a small early nudge is needed to cause a major orbital change.

 

More here.....

[ldsoftwaresteve]

It is a good idea, but it's dependent on gravity as an attracting force.

[infamous]

It is a good idea, but it's dependent on gravity as an attracting force.

Good idea, yes, but also dependent upon how much advance knowledge we have. For this approach to work, we will need a considerable amount of advance warning, enough time to allow this slight manipulation of trajectory to be effective. Therefore the need for a comprehensive study of 'near earth objects', NEO's, and a concerted effort to find the NEO's that have as yet gone undetected.

[Pangolin]

You could just move the whole planet that way. I don't have the time to hunt down the link but somebody has done the calculations to move the planet away from the eventual transition of the sun to a red giant.

 

The idea is that you take a few thousand asteroids from the Oort cloud and send them slingshotting past Earth. Each pass would pull the Earth into a slightly higher orbit. Using the gas giants as a second bumper you could transfer enough of the momentum from their orbits to boost Earth into a higher/cooler orbit.

 

It would only take a few thousand years.