Lemmy Lemmy:
In about 4B years, the moon will have moved far enough away from earth that the gravitational pull won't maintain the Earth's rotation. This will cause the planet to wobble and destroy all life on-board. The sun will gobble up the planet in 5-8B years, but no one will be around to see the show.
Except for a strange man riding a fifties-era Police Box with his busty-- er, I mean trusty companion.