Continuing our series on interesting geographic concepts that you may never have thought about, this week’s term is Spheroid. A spheroid is like a sphere, but is not uniformly round. As it turns out, the earth’s shape is not a perfect sphere due to physical and gravitational variations throughout the planet. An example of this unevenness is that the North Pole is actually slightly further from the Equator than the South Pole. The earth’s somewhat irregular shape is therefore better represented as a spheroid. A sphere is a reasonable approximation of the shape of the earth for general purposes, such as making a globe. Precise and detailed mapping requires using a more accurate mathematical model: a spheroid.