2 Important WordsCrescent: less than half of the moon visible to Earth is litGibbous: more than half of the moon visible to Earth is lit
3 More Important WordsWaxing: illuminated portion of the moon facing Earth is increasingWaxing is from the Old English weaxan meaning “to grow.”Wax on light (from new moon to full)Waning: illuminated portion of the moon facing Earth is decreasingWaning is from the Old English wanian meaning “to lesson”Wane off light (from full moon to new)
4 Still another important word Quarter Moon: Half of the moon facing the Earth is illuminatedBut wait… if we see half the moon lit, was isn’t it called a half moon?This is because the moon is a quarter (or three quarters) through its cycle of phases (or we see a quarter of the entire moon lit…)
5 Your moon model data table should look like this! Be SureTo LookAt The#s
6 In your model what represented the Earth, the Sun and the Moon? Earth: YouSun: the lampMoon: the Styrofoam ball on the stick
7 How much of the lighted part of the ball did you see when facing the lamp? NONE!
8 Explain what happened to the illuminated portion of the moon after each turn. The portion of the moon illuminated (lit) increased with each turn until the entire moon facing the Earth was illuminated. After this the portion of the moon illuminated decreased with each turn.
10 Whether you could see it or not, how much of the ball’s surface was always lit by the lamp? HALF OF THE MOON IS ALWAYS ILLUMINATED BY THE SUN!We just do not always see all (or any) of this half here on Earth!
11 Why do we see different phases of the moon? The moon revolves around the Earth, so the relative positions of the Earth, moon and sun cause the phasesThe changing amount of the lit portion of the moon visible on Earth = Phases
13 What would happen if the model was not above head? Moon would be dark at full moon location – in your shadowWould be a lunar eclipse!
14 Moon InfoIt takes the same amount of time for the moon to rotate on its axis as it does to revolve around the Earth (27.3 days)This is why the Earth only sees one side of the moon – in order to see the other side you need to get on a space ship and go around the moon!There are 29.5 days from a new moon to the next new moon
15 Moon Info The lit part of the moon always points towards the sun. When waxing: light is on the rightWhen waning: shadow is on the right
16 The moon rise, moon setThe time of the moon rise and set depends on its phaseRises in the East and sets in the West – due to Earth’s rotationRemember: moon rises about 50 min later each day of the moon phase cycle (~ 25 to 75 mins)PhaseRise TimeMidpoint in skySet TimeNewSunriseNoonSunset1st quarterMidnightFull3rd quarter
17 Can you identify the phase? FullLast (3rd) QuarterWaxing GibbousWaning CrescentFirst QuarterWaning GibbousNewWaxing Crescent