Do planetary magnetic fields slow the movement of conductive extraplanetary moving objects via induction?
A fixed magnetic field will induce an electrical current in a conductive object moving through the field.


No. It will induce an EMF in one direction as described in HyperPhysics. It will not induce a current since there is no return path.

This is different from induction braking, where you have a magnet with a non-uniform field moving near a conductor. It is the changing magnetic field at points within the conductor that induces the EMF and causes currents.

Alternatively, we can consider how electromagnetic fields transforn according to Relativity. If an object is moving at constant velocity through a uniform B field then, in its rest frame, it will experience a combination of uniform E and B fields which would not produce a current.  (Any current would have to be due to the spacial rate of change of the field, which would be tiny on the scale of the Earth's field.)