Book 1, Question 79
Why Does the Moon Change Shape? Slices of Sunlit Moon!
The Moon looks different night after night, but it is always a big rocky ball. The Sun lights one side of the Moon while the other side stays dark, and as the Moon orbits Earth we see different slices of the lit side. The page shows new, crescent, half and full phases. The dark part of the Moon has not disappeared, it is just not lit by the Sun. In a dark room, use a ball as the Moon and a lamp as the Sun and walk around the ball to see the shape change.
From the book
Page from A Million Whys Book 1
More fun facts
- There are eight Moon phases: new Moon, waxing crescent, first quarter, waxing gibbous, full Moon, waning gibbous, third quarter, and waning crescent.
- The whole cycle repeats about every 29.5 days.
- Waxing means the lit part is growing. Waning means it is shrinking.
- At first quarter, you see half of the Moon's sunlit side. It rises around midday and sets around the middle of the night.
- A full Moon rises around sunset. At new Moon, the Moon is up during the day, but we cannot see its lit side.
- Moonlight is really sunlight bouncing off the Moon.
- Like Earth, the Moon has a day side and a night side.
Sources: NASA Science, NASA Space Place
Questions kids ask
How long does it take to go through all the Moon phases?
About 29.5 days.
What do waxing and waning mean?
Waxing means the lit part we see is growing. Waning means it is shrinking.