Bode , Johann Elert

(1747–1826) German astronomer

Born in Hamburg, Germany, Bode was the director of the Berlin Observatory and popularized a discovery made earlier in 1772 by Johann Titius of Wittenberg. This was a simple but inexplicable numerical rule governing the distance of the planets from the Sun measured in astronomical units (the mean distance of the Earth from the Sun). The rule, known as Bode's law, is to take the series 0, 3, 6, 12, 24 …, add 4 to each member, and divide by 10. The result is the distance in astronomical units of the planets from the Sun. The law and its application can be tabulated and, provided that the asteroids are counted as a single planet, quite an impressive fit can be achieved. It breaks down for Neptune and is hopelessly wrong for Pluto. It played a role in the discovery of Neptune by Urbain Le Verrier in 1846. It is not known whether the law is simply a pure coincidence, or whether it is a consequence of the way in which the solar system formed.