[填空题]
The Moon orbits the phv0ujjje . y;mrt819Earth such that the syq-gv1.ct9 :e : gagqe.yjnu4ame side always faces the Earth. Determine the ratio of the Moon’s spin angular momentum (uq94e: 1g-c .:qj.gea vny ytgabout its own axis) to its orbital angular momentum. (In the latter case, treat the Moon as a particle orbiting the Earth.) $\times10^{ -6}$