Question

Astronauts discover an earth-size planet without a magnetic field. To create a magnetic field at the north pole with the same strength as earth’s, they propose running a current through a wire around the equator. What size current would be needed?

Answer 1

It depends on the diameter of the "earth". If it is exactly the same size as Earth, then a 7,917.5 mile long wire would be required.

"The strongest current was found around the galaxy 3C303, whose core is the origin of a massive matter jet."       (POPULAR SCIENCE, The Strongest Electrical Current)

     This galaxy is admitting 1018 amps. This equals one TRILLION bolts of lighting.

The Earth's magnetic field at its surface ranges from 35 to 65 microteslas.