Phases of the Moon

Understand the phases of the Moon by observing the positions of the Moon, Earth and Sun. A view of the Moon from Earth is shown on the right as the Moon orbits Earth. Learn the names of Moon phases and in what order they occur. Click Play to watch the Moon go around, or click Pause and drag the Moon yourself.

  Launch Gizmo


  • Define rotation and revolution.
  • Explain why we see Moon phases.
  • Relate Moon phases to the Moon's position.
  • Name the phases of the Moon and list them in order.
  • Notice that we always see the same face of the Moon. (Extension)
  • Explain the meaning of a year and a day. (Extension)
  • Find the length of a lunar year and day. (Extension)
  • axis, crescent, First Quarter, Full Moon, gibbous, illuminate, New Moon, orbit, revolve, rotate, Third Quarter, waning, waxing