I guess the gravity relations would not change much. You see, the mass of the Earth is still there, most of it will fall back together to form a planet again. A few hundred million years on, life might be happening again. The moon has actually been formed when a Mars-sized object collided with Earth long ago. Part of the debris vanished into space (escape velocity), part fell back and the bits that were in orbit clumped together to make the moon. At least that's one of the foremost theories on that. It would explain why always the same side of the moon points to earth, which is totally rare.
I guess the gravity relations would not change much. You see, the mass of the Earth is still there, most of it will fall back together to form a planet again. A few hundred million years on, life might be happening again. The moon has actually been formed when a Mars-sized object collided with Earth long ago. Part of the debris vanished into space (escape velocity), part fell back and the bits that were in orbit clumped together to make the moon. At least that's one of the foremost theories on that. It would explain why always the same side of the moon points to earth, which is totally rare.