> it's entirely based on earth's magnetic field. No, north is based on Earth's rotational axis. Magnetic north is not true north, as a good topographic map wil

> it's entirely based on earth's magnetic field. No, north is based on Earth's rotational axis. Magnetic north is not true north, as a good topographic map will indicate. North is a convention of rotation direction: from above the north pole, a planet appears to rotate counterclockwise.