Asteroids, Charge, and Magnetic Fields
Date: Spring 2012
If a fragment from an asteroid falls to Earth and a static electric charge is built up in the fragment as it falls, does it generate a magnetic field? If so, why?
Yes, it would. A moving electric charge creates a magnetic field.
The “why” basically comes from relativity. When the charge moves, its electrical interaction with other charged objects changes because of the way spacetime distorts. That change manifests as a magnetic field.
Richard E. Barrans Jr., Ph.D., M.Ed.
Department of Physics and Astronomy
University of Wyoming
Current is the motion of electric charge from one location to another. Current, as we usually think of it, is the movement of electrons within a wire, and this current will create a magnetic field surrounding the wire. Maxwell’s equations define the strength of this field based on the value of this current (amount of charge flowing through the wire each second). Current is not confined to wires, however; electrons flowing in space will define a current (and associated magnetic field) as well. For a charged asteroid, you can define current associated with its charge moving through space and an associated magnetic field.
Kyle J Bunch
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Update: June 2012