The Earth and Moon

The scale model of the Earth is 5.5 inches. The scale model of the Moon, 1.5 inches.


Earth, with the Moon at the appropriate distance.

Earth is perhaps the System’s most interesting planet. Atmospheric conditions allow for frequent movement of water in all three phases - solid, liquid, gas. The planet’s 23-degree tilt produces seasonal changes. Continents move about over a somewhat liquid interior. Mountains form and are eroded. Earth makes 365 1/4 rotations in one revolution about the Sun.

Earth has a rather large moon which revolves about the planet in 29 1/3 Earth days. The Moon also has a 29 1/3 day rotation, so that one hemisphere always faces the Earth. The Moon does not have an atmosphere.