Earth and Moon space-time warp. Artwork of the Earth (lower left) and the Moon (upper right) on a grid representing space-time. This grid deforms (warps) under the influence of massive objects such as planets, moons and stars. The warping of this grid represents the effect of gravity. The Moon's diameter is only 27 percent of the Earth's, and its mass is less than 2 percent of the Earth's, so the Moon effectively orbits the Earth, while both orbit the Sun (not seen). The mean Moon-Earth distances is around 380,000 kilometres.