Hello, my name is Kiley and welcome to "Our Moon: Part 2"!
Before watching this video, be sure to watch "Our Moon: Part 1."
In this video, you'll learn about why our Moon sometimes shines so brightly and why it appears
to change shape in our night sky. Let's get ready to learn about the many phases of our Moon.
Have you ever been outside at night and seen a full moon? It can shine very bright and almost
seem like someone turned on a light. But the Moon itself doesn't produce any light, so hmm, what
makes it glow at night? The Sun! The Sun? Yes, you heard correctly, the Sun. The Sun shines on our
Moon. The amount it shines on, or illuminates, the Moon varies or is different as the Moon travels
around our planet and as our planet travels around the Sun. These different amounts of light bouncing
or reflecting off our Moon make the Moon appear to be different shapes. These are called moon phases.
Moon phases are often referred to as the different "faces" of the Moon. This goes back to a folktale
people tell about a "Man in the Moon." Since people thought there was a man in the Moon,
it was thought that he was turning his face towards and away from the Earth.
Astronomers know there isn't a Man in the Moon, and they know why the Moon appears differently
during different times of the month. It takes the moon 29 and a half days to go through
eight different phases. As the Moon orbits our Earth, the Sun lights up different parts of it,
and the Earth gets in the way of some of the light. It seems like the Moon is changing shape,
but really, it isn't. This is because only part of the Moon is in sunlight, and part is in shadow.
The eight phases of the Moon are... New Moon – our Moon is not illuminated by the Sun at all, so we
do not see it; Waxing Crescent – our Moon appears in the sky as a tiny crescent or fingernail shape;
First Quarter – half of the Moon is visible in this phase;
Waxing Gibbous – most of the Moon is illuminated;
Full Moon – during this phase, the entire face of the Moon is illuminated. Sometimes,
depending on our Earth's orbit, the moon is so brightly illuminated by the Sun,
we can see it during the daytime. Waning Gibbous – most of the Moon is illuminated;
Last Quarter – half of the Moon is illuminated; and Waning Crescent – again,
like the Waxing Crescent, the Moon appears as a tiny crescent of light.
If the Moon is moving from the New Moon phase to the Full Moon,
it is said to be waxing, which means getting bigger. Then, as the Moon moves from the Full
Moon phase to the Waning Crescent, it is said to be waning, which means getting smaller.
The Moon moves through the phases in a cycle.
Once it becomes new, it begins the cycle all over again and repeats every 29 and a half days.
Some calendars mark the phases of the Moon so you can see which phase will be visible at that time.
Check them out with a parent and plan some Moon viewing!
To continue learning about our Moon, be sure to watch "Our Moon:
Part 3." To practice what you've learned about our Moon and other interesting science topics,
be sure to play our fun online games and quizzes. Until next time, remember to always be clever!