Lunar Capture

Origins of the Earth's Moon

Angular Momentum

Angular momentum depends upon the speed of rotation and upon the distribution of mass around the axis of rotation (17). The Earth-Moon system’s angular momentum is best imagined as the spinning ice skater that can increase or decrease her rate of spin by moving her arms in our out. Pulling in her arms will increase the rate of spin while letting out her arms slows the spin. In the same way, a closer Moon equates to a faster spin of the Earth-Moon system and a more distant Moon equates to a slower spinning of the Earth-Moon system.Thus, as the Moon retreats further, the Earth’s spin slows, just like the skater slowing down by moving her arms away from her body. Newtonian law says that angular momentum must be conserved. This law is universal and all the planets and moons follow it precisely. However, no one has yet been able to fully explain the dynamics we see in our local system; the Earth-Moon system is unexplainably out of balance.