Did Early Earth Spin On Its Side?

New theoretical modeling of the ancient history of the Earth and the Moon suggests that the giant collision that spawned our natural satellite may have left Earth spinning very fast, and with its spin axis highly tilted. Computer simulations of what followed the collision, sometimes referred to as the “big whack,” show that, following this event, and as the young Moon’s orbit was getting bigger, the Earth lost much of its spin as well gained a nearly upright orientation with respect to the ecliptic. The simulations give new insight into the question of whether planets with big moons are more likely to have moderate climates and life.”