I read an interesting article a couple of years ago, unfortunately I don't remember where. It had to do with the affect of Gravity on planets. We already know the speed of Light and that it takes so many minutes or hours for the light of a planet to reach us. I'd like to know if Gravity's affect is instantaneous or does it have a "speed" of some sort. Here's a hypothetical situation: we've invented Teleportation of mass, we even built a machine big enough to teleport a moon. If you teleport something of that mass and it arrives instantaneously, does it's gravitational affect on nearby objects take a finite amount of time to happen or is it also instant?