The Close Approach – A Lunar Model
What if the moon weren’t a three days travel from the earth? What if it didn’t always show one face towards us? Have you ever thought about how a change in the orientation or dynamics of our moon would impact our everyday lives?
The past evolution of the moon’s orbit has interested scientists since at least George Darwin’s study of rotating viscous spheres in the late 19th century. It is typically thought that the moon has been steadily retreating from the earth for the past four plus billion years and that it will continue to retreat. Strangely though, today when the moon’s current rate of retreat is calculated backwards it is found that the moon approaches the earth much more recently than four billion years ago – rather only 1.8 billion years ago! It is the investigation of this discrepancy which has ultimately led to the hypothesis of a close lunar approach in the history of the earth-moon system.
Let’s look at things from the perspective of the CALM. Consider that at one time, in the not so distant past, the moon approached the earth, coming much closer than it is now. This happened during a great calm in our earth’s history. For hundreds of millions of years the earth saw temperate weather, mild seasons, and a relatively consistent environment. But this long period of calm was jarringly disrupted when the moon literally got “too” close. The close proximity of the two bodies set off a series of cataclysmic heating events that resulted in what is known as the Permian Extinction or the Great Dying (the greatest extinction of all time). Read More