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[music playing]

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[wolf howls]

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- Have you ever looked
at the Moon

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and it looked close enough
to touch?

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Or wondered why it doesn't
stay the same

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night after night?

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Why does it change?

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[music playing]

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kids: "Our World."
[laughter]

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- I love to look up
at the Moon at night,

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especially when it's
big and round and bright,

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but I just found out

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that the Moon's light
actually comes from the Sun.

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- That's right,
all solid surfaces

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reflect light back to us.

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The Moon reflects light
from the Sun.

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The Sun emits the light.
The Moon reflects it back.

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- So the Moon
doesn't make its own light.

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It reflects sunlight.

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But why does the Moon
change shape every night?

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- The Moon doesn't
change shape every night.

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What we see is
the Moon being lit

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with different amounts
every night,

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so it appears to change shape,
which we call the phases.

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When the Moon is "new,"

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there's no sunlight
reflecting off of it

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back towards us.

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That's why we can't see it.

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The Sun is still
shining on the Moon,

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but it's shining
on the other side of the Moon,

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and therefore
we can't see it.

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When the Moon is full,

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the sunlight is reflecting
off the full disk of the Moon

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and we see it
as a full moon.

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In between those phases,

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the Moon goes through "waxing,"
which is increasing.

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It's an old word
for "increasing."

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Waning, which is
an old word for "decreasing."

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It refers to the amount of
light on the Moon.

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So as you seen the Moon
go from full,

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then it gets
a little less light,

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and so it's a waning moon.

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It goes through
waning gibbous,

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waning half,
and waning crescent.

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Then it's a new moon.
We can't see it.

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There's no light
reflecting off of it.

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And then it'll
start to come back slowly,

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and it'll go through
waxing crescent,

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waxing half,
and waxing gibbous.

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Full moon always rises
at sunset,

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so if you want to see
a nice, full moon,

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go out at sunset.

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After that, the Moon rises
50 minutes later each day.

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So sometimes
you'll see it at night,

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but sometimes you can see the
Moon during the day as well.

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The phases of the Moon
arise because

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the Moon is rotating
on its axis.

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Rotation is when a body
rotates around its axis.

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Both the Moon and the Earth
rotate around their axes.

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The Moon revolves
around the Earth,

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and the Earth
revolves around the Sun.

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- Whoa!
That was some rotation.

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So the Moon, Earth, and Sun
work together in a system.

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The phase of the Moon
depends on

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how much of the sunlit
side of the Moon we see

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as it revolves around Earth.

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Just like the full moon
rises at sunset,

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the new moon always
rises near sunrise.

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But we can't see
the new moon during the day

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because the side of the Moon
the Sun is shining on

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is turned away
from the Earth at that time.

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And that pattern repeats
over and over again.

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Here's something
you can do at home.

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Go outside and look
at the Moon every day

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for a couple of months.

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Draw a picture
of what you see,

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then try making
your own calendar

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that shows the phases
of the Moon.

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Before long, you'll be able
to predict

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what phase of the Moon
comes next.

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For "Our World," I'm Mishay.

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See you next time.

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Oh, look, a waning crescent.

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[music playing]

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kids: "Our World."
[laughter]