[music playing]
[wolf howls]
- Have you ever looked at the Moon
and it looked close enough to touch?
Or wondered why it doesn't stay the same
night after night?
Why does it change?
[music playing]
kids: "Our World." [laughter]
- I love to look up at the Moon at night,
especially when it's big and round and bright,
but I just found out
that the Moon's light actually comes from the Sun.
- That's right, all solid surfaces
reflect light back to us.
The Moon reflects light from the Sun.
The Sun emits the light. The Moon reflects it back.
- So the Moon doesn't make its own light.
It reflects sunlight.
But why does the Moon change shape every night?
- The Moon doesn't change shape every night.
What we see is the Moon being lit
with different amounts every night,
so it appears to change shape, which we call the phases.
When the Moon is "new,"
there's no sunlight reflecting off of it
back towards us.
That's why we can't see it.
The Sun is still shining on the Moon,
but it's shining on the other side of the Moon,
and therefore we can't see it.
When the Moon is full,
the sunlight is reflecting off the full disk of the Moon
and we see it as a full moon.
In between those phases,
the Moon goes through "waxing," which is increasing.
It's an old word for "increasing."
Waning, which is an old word for "decreasing."
It refers to the amount of light on the Moon.
So as you seen the Moon go from full,
then it gets a little less light,
and so it's a waning moon.
It goes through waning gibbous,
waning half, and waning crescent.
Then it's a new moon. We can't see it.
There's no light reflecting off of it.
And then it'll start to come back slowly,
and it'll go through waxing crescent,
waxing half, and waxing gibbous.
Full moon always rises at sunset,
so if you want to see a nice, full moon,
go out at sunset.
After that, the Moon rises 50 minutes later each day.
So sometimes you'll see it at night,
but sometimes you can see the Moon during the day as well.
The phases of the Moon arise because
the Moon is rotating on its axis.
Rotation is when a body rotates around its axis.
Both the Moon and the Earth rotate around their axes.
The Moon revolves around the Earth,
and the Earth revolves around the Sun.
- Whoa! That was some rotation.
So the Moon, Earth, and Sun work together in a system.
The phase of the Moon depends on
how much of the sunlit side of the Moon we see
as it revolves around Earth.
Just like the full moon rises at sunset,
the new moon always rises near sunrise.
But we can't see the new moon during the day
because the side of the Moon the Sun is shining on
is turned away from the Earth at that time.
And that pattern repeats over and over again.
Here's something you can do at home.
Go outside and look at the Moon every day
for a couple of months.
Draw a picture of what you see,
then try making your own calendar
that shows the phases of the Moon.
Before long, you'll be able to predict
what phase of the Moon comes next.
For "Our World," I'm Mishay.
See you next time.
Oh, look, a waning crescent.
[music playing]
kids: "Our World." [laughter]