4. The Moon is currently receding from the Earth at less than 6 inches per year. The Moon could never have been closer than about 11,000 miles or it would have been broken up by tidal forces. If the rate of recession is assumed to have averaged about 6 inches per year, the Moon's present distance of about 250,000 miles implies an age for the Moon of no more than 2.6 billion years. However, the tidal forces between Earth and Moon are not constant, and so simply extrapolating from the current rate of change is not strictly valid. | 4. The Moon is currently receding from the Earth at less than 6 inches per year. The Moon could never have been closer than about 11,000 miles or it would have been broken up by tidal forces. If the rate of recession is assumed to have averaged about 6 inches per year, the Moon's present distance of about 250,000 miles implies an age for the Moon of no more than 2.6 billion years. However, the tidal forces between Earth and Moon are not constant, and so simply extrapolating from the current rate of change is not strictly valid. |