Did you know that the Moon was only about 18,000 miles away from Earth when it formed, some 4.5 billion years ago?

So say the sources I’m using for the next post in the cat evolution series (a post which follows life on Earth from its earliest days to the moment when a four-footed Devonian/Carboniferous fishy ancestor of cats and other tetrapods stalked out of sea and decided that dry land was the place to be).

Having the Moon so close billions of years ago made for some intense ocean tides, of course. Friction from these twice daily massive global water surges slowed down the planet’s daily rotation, which may have been less than six hours at the start.

As Earth’s rotation slowed down to its current 24-hour day, the Moon was forced to move farther away in order to conserve angular momentum in the Earth-Moon system. It’s almost 240,000 miles away now.

No wonder it takes almost half a week to get there!

The most recent lunar rock collector that dropped in for a visit, from China, has recently retrieved some material that suggests the Moon stayed geologically active far longer than anyone thought.

Perhaps it was even active during the early “Age of Mammals”!

Featured image: pathdoc/Shutterstock