If Earth were a 4-inch globe, how big would the Moon be, and how far away? The Moon is .27 times the Earth's diameter, so about 1-inch and roughly 10 feet away. This assumes an average Earth-Moon distance of about 240,000 miles. We're talking about orders of magnitude here, so finding scale models to represent things things are as close as we can find.

Yet practically speaking, just how far away is 240,000 miles, the average Earth-Moon distance? It would take a jet flying Mach 1.3 exactly 10 days to get there. How can the Earth keep the Moon in its gravitational field when the Moon has only about 1.2% of the Earth's mass? In a scale system where the Earth has a 4-inch diameter, what is the scale weight of that scale Earth model?

Finding exact scale for relative sizes of planets and moons is not an exact science. That said, we've found some great approximations, so close to actual ratios that the idea of size and distance are well-conveyed. Our 4" Earth is a great depiction alonside a 1" moon. The Moon is actually .27 times the diameter of Earth, so it looks great hanging some 10-feet away! See our Earth-Moon system here, hanging on our back porch: photo of E-M hanging. We also have a 2.25" "Mars" that can be hung between approximately 1440-ft, to 10,400-ft away. Mars orbits relative to Earth with a wide range of varying relative distances.