Earth’s Gravitational Attraction to the Moon and the Resulting Tides

The revolution and rotation of the Moon are well understood and there is little debate as to their mechanisms in the present day. However, it is generally unknown to the public that the Moon is responsible for the current length of our day. Research in the early part of the 20 th century found that the Moon was much closer in the past and is getting farther everyday (Street, 1917). More current investigations found the Moon to have a drag effect on the Earth, causing our days to go from 18 hours long to the current 24 hours. While the Moon orbits the Earth, it will continue to lengthen our days (Brosche, 1984). There is also evidence that if it were not for the Moon, the Earth’s tilt would be much more variable (one model suggests it would change from eleven to forty degrees) (Peterson, 1993). This would have had a tremendous impact for life on Earth. With the Earth’s tilt varying, the Earth’s climate would be much more erratic, making it difficult for more complex life forms to develop.