Since the Earth is moving around the Sun in its orbit at approximately 32000 mph or Apx. 9 miles per second and If the speed of gravity is the same as the speed of light then the moon, being one light second away, must be orbiting where the Earth was one second ago. That is to say 9 miles behind where we really are. Since, with lazer measurements, we can measure the distance to the Moon to an accuracy of a few feet. We should be able to check if the Moon is 18 miles closer to the earth when it is on the leading side of the Earth's orbit than it is when it is on the trailing side of the earth's orbit (averaging out the elipsis of the Moon's orbit). Or is the Moon the same distance from the Earth (on average) on both sides of its orbit? (the speed of gravity is infinite) Does anyone know if this measurement has ever been done?
If the speed of gravity is infitite then, by the process described in the earlier "speed of gravity" topic, signals, energy and possibly spacecraft can go faster than light.