Chladni’s work on meteorites was stimulated by the observation by the astronomers Johann Bode and Johann Titius of an apparent a gap between Mars and Jupiter. Based on the geometrical distances between the other known planets we would expect to find another planet at that distance from the sun. Chladni took this as evidence that meteorites might have their origin in metal and rock from this unformed planet. Later astronomers would locate the asteroid belt in just this area between Mars and Jupiter.