The Kardashev scale is a method of measuring a civilization's level of technological advancement based on the amount of energy it is able to use. The scale was proposed by Soviet astronomer Nikolai Kardashev in 1964. The scale has three designated categories called Type I, Type II, and Type III. A Type I civilization is able to harness all of the energy available on its home planet. A Type II civilization can harness all of the energy of its host star. A Type III civilization can control energy on the scale of its entire host galaxy.