The document discusses lunar phases and what causes them. It explains that moon phases are caused by the changing positions of the sun, earth, and moon relative to each other. As a result, we can only see certain lit parts of the moon from earth. There are 8 main phases - new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and waning crescent - that each occur over the course of about a week as the moon orbits earth.

1. Lunar Phases

2. The moon does not actually produce its own light
It reflects light from the sun
The Moon

3. • Moon phases are the portion of the lit moon as seen from
Earth.
• Moon phases are caused by the Sun, Earth, and Moon being
in different positions relative to each other.
• As we look out from Earth, we can only see certain parts of
the lit moon.
• SHADE IN THE SHADE!
What are moon phases and what causes them?
New
Moon
Waxing
Crescent
First
Quarter
Waxing
Gibbous
Full
Moon
Waning
Gibbous
Third
Quarter
Waning
Crescent
New
Moon
~ 1 week ~ 1 week ~ 1 week ~ 1 week
Waxing Period
Light “creeps” across Moon from
Right to Left
Waning Period
Darkness “creeps” across Moon
from Right to Left

9. Lunar PhasesAnimation

10. WHY ISTHE LIGHT ONTHE LEFT
DURINGTHEWANING PERIOD?

11. WHY ISTHE LIGHT ONTHE LEFT
DURINGTHEWANING PERIOD?

12. Waxing means to grow in light
• This means that the lit part of the moon is getting bigger.
• It wants to ultimately become a full moon.
• Example: Waxing Crescent, 1st Quarter, Waxing Gibbous
Waning means to decline in light
• This means that the lit part of the moon is getting smaller
• It wants to ultimately become a new moon.
• Example: Waning Crescent, 3rd Quarter, Waning Gibbous
Waxing vs.Waning Moon

13. Sometimes, there are 2 full moons in the same month.
But that only happens “once in a blue moon”
- Moon phase = Full Moon
- Average length of month = 30 days – our calendar does
not follow the lunar cycle, but there are some calendars
in other cultures that do!
- Sometimes we have two new moons…the lunar cycle
begins itself again at the end of the month.
Blue Moon

14. This picture was taken by my
phone. My daughter and I were
on the playground. She looked up
and said...Hey daddy, there is the
moon and its not night-time. It
was a summer afternoon a little
after 12 noon.
What phase is the moon in?
Why can we see the moon at
noon?
The Moon at Noon