Listening practice: The Moon that is slowly shrinking

On a clear night, the Moon looks still. But inside that quiet world, something is changing. The Moon is slowly losing heat. As its interior cools, the whole body contracts, becoming a little smaller. NASA estimates that the Moon has become more than one hundred and fifty feet, or about fifty meters, narrower over the last several hundred million years. That sounds tiny for a world, but it is enough to bend and crack the Moon's crust.