In prior years, students learned the implications of the spherical-Earth concept and Earth’s relationship to the Sun. In grades 6-8 students study the Moon’s changing phases and learn to distinguish between phases and eclipses

Most objects in the Solar System are in regular and predictable motion. These motions explain such phenomena as the day, the year, phases of the Moon, and eclipses.

The Moon’s monthly cycle of phases can be explained by its changing relative position as it orbits Earth. An eclipse of the Moon occurs when the Moon enters Earth’s shadow. An eclipse of the Sun occurs when the Moon is between the Earth and Sun, and the Moon’s shadow falls on the Earth.

Earth is the third planet from the sun in a system that includes the Moon, the Sun, seven other major planets and their moons, and smaller objects such as asteroids, plutoids, dwarf planets and comets. These bodies differ in many characteristics (e.g., size, composition, relative position).

Gravity is the force that keeps planets in orbit around the Sun and governs the rest of the motion in the Solar System. Gravity alone holds us to the Earth’s surface.

Our Sun is one of hundreds of billions of stars in the Milky Way galaxy. Many of these stars have planets orbiting around them. The Milky Way galaxy is one of hundreds of billions of galaxies in the universe.