If a planet's magnetism could be determined and manipulated, it seems to me
that anyone could operate a UFO by interacting with the planet's polarities.

In other words, flying a UFO should be a simple matter of increasing the
attraction or repulsion ***of the craft*** in relation to the planet it's
visiting. 

Need to land - increase the attraction (within the craft itself). Need to fly
- increase the repulsion.

???

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Angels exist - and this artist has seen them!
http://www.rcip.com/nerdgerl/default.htm