Modeling the Earth and moon would be easier. If we use that marble for the moon, Earth would be a tennis ball, with a diameter of 6.7 centimeters.

Learn the differences between our Earth, the Sun and the Moon. Then explore how together they create day and night and our different seasons with their orbits.

This diagram easily breaks down the science of what's happening in space with the sun, moon, and Earth during the April 8 total solar eclipse.

Only the giant impact explains what we see in moon and Earth samples today. Related Stories. Scientists discover ‘hidden structures’ deep beneath the dark side of the moon.