Explore experiments

Earth and the Moon, to scale

The real Earth-Moon system, in real units. One grid cell is 1000 km, one mass unit is 10^22 kg, one second is ten minutes. Nothing is tuned: Earth carries its measured 5.97 x 10^24 kg, the Moon sits 384,400 km away, and the pull is Newton's F = G M m / r squared with G converted into these units. The 27.3-day orbit that comes out is what those numbers produce. Only the globes are drawn larger than life so you can see them; their masses are untouched.