It's possible that by slightly magnetizing asteroids we can steer them out of earth's path by predicting interactions with the magnetic fields out there.
-- Voice, Mar 01 2011

Remote Control Moon Remote_20Control_20Moon
Combine with this idea [Dub, Mar 01 2011]

This sounds so cool, though I know nothing about it. I want to drive an asteroid. [+]
-- xandram, Mar 01 2011


It's also possible that we can't.

Do we know which?
-- MaxwellBuchanan, Mar 01 2011


Presumably easy-peasey to find out which, by building a big solar-powered-electro-magnet in space, and see what sticks
-- Dub, Mar 01 2011


Some asteroids are already magnetic.
-- ldischler, Mar 01 2011


If the orbital dynamics are chaotic, then arbitrarily small magnetic perturbations should suffice to save the earth. Problem is, it may require arbitrarily large computers.
-- mouseposture, Mar 02 2011


// If the orbital dynamics are chaotic, then arbitrarily small magnetic perturbations should suffice to save the earth.//

Or destroy it. That's the problem with chaos, it's unpredictable.
-- ldischler, Mar 02 2011


Are you sure? My understanding was that a chaotic system's only unpredictable in principle if you try to predict for all future time. Since states diverge exponentially, if you're predicting a finite time into the future, there is, for any desired prediction accuracy, a finite accuracy (for measurement and computation) which suffices to achieve it. Of course, that accuracy will, in general, not be practically achievable (hence the crack about arbitrarily large computers).

Also, there are control systems for some chaotic systems that don't rely on actually solving the system.
-- mouseposture, Mar 03 2011


The point is, if an arbitrarily small perturbation would suffice to save the earth, then an similarly small perturbation could make it hit the earth. Perturbations such as a knot in the solar wind, a solar flare, or a micrometeorite strike. These can't be calculated, no matter how much computing power you have.
-- ldischler, Mar 03 2011


[ldischler] //Some asteroids are already magnetic.//

Well, that's easy then! Simply reverse the Earth's magnetic field and repell them!
-- Dub, Mar 04 2011


Since a magnetic field can only impart a turning moment to the asteroid no change in orbit can be expected from changing its magnetisation.
-- neelandan, Mar 04 2011


Since magnets are bipolar, any turning motion, or other perturbations would only increase the chances of bringing the asteroid down towards one of the poles. Perhaps slightly preferable to an equatorial crash, but still pretty bad.
-- ye_river_xiv, Oct 11 2011


//Since a magnetic field can only impart a turning moment//

//Physics double-take moment//

A uniform magnetic field, that is, which it will be if we are considering the magnetic field of the earth out at the distance of a typical asteroid orbit.
-- neelandan, Oct 15 2011


Space: the final affront here.
-- MaxwellBuchanan, Oct 15 2011


I love the optimistic brevity of this idea.
-- Alterother, Oct 16 2011



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