The day came when man had mined a critical mass of the Earth’s minerals. The mass was deemed critical, because of the extraordinary strain this placed on the outer layer.
The planet changed shape, becoming more elliptical with its every rotation. At first, this was hardly noticeable; later, a daily shift could be observed, a daily measure taken. The resonant frequency of the Earth quickened.
It was inevitable that the Earth’s orbit of the sun would change. After all, the planet was spinning ever faster, getting hotter, with less holding it together.
The crust began to lift.
That was when we fell off the Earth — the last humans — cast into space by our own burrows and builds.