3. The earth's magnetic dipole moment is 8.0×10²² Am². (a) Treating the earth's magnetic field as a dipole (like a current loop embedded deep within the earth), what is the

magnetic field strength on the surface of the earth at the earth's north magnetic pole? The magnetic field of Mars is weak enough to make terraforming it difficult. To create a stronger magnetic field, some scientists have proposed running a current through a wire around its equator. (b) What length of wire would be needed to form a single loop around the equator of Mars? (c) Ignoring the residual magnetic field that Mars already has, what is the size of the current that would need to run through this wire to produce a magnetic field at its north pole with the same strength as earth’s (as calculated in (a))?