Institution(s): 1. CSUF
In view of the recently reported chemical similarities between lunar and earth specimen, interest in the lunar origin has been reawakened. A new approach is presented here. A necessary condition for a lunar spin-off requires that the primitive earth has expanded since its inception. Then, utilizing the non-controversial conservation of total angular momentum of the earth-moon system, one can readily derive the initial physical conditions for the moon's escape (spin-off) from the upper surface of a rapidly spinning, diminutive earth. Detailed calculations will be presented for both the Moon-Earth and Triton-Neptune's early evolutionary developments. The results have implications to theories relating the origin of the solar system.