Ready Jet Go
Amy Mainzer Explains Why the Moon Changes Shape
Clip | 1m 31sVideo has Closed Captions
Astronomy Amy Mainzer explains the phases of the moon.
Astronomy Amy Mainzer explains the phases of the moon.
Problems playing video? | Closed Captioning Feedback
Problems playing video? | Closed Captioning Feedback
Ready Jet Go
Amy Mainzer Explains Why the Moon Changes Shape
Clip | 1m 31sVideo has Closed Captions
Astronomy Amy Mainzer explains the phases of the moon.
Problems playing video? | Closed Captioning Feedback
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and wondered why it looks like it's changing shape?
Sometimes it looks like it's full and round, and other times it's just a half-circle.
Sometimes it's not there at all.
What's going on with that?
Hi, I'm astronomer Amy Mainzer.
I've got the Moon right here in my hands.
Well, okay, it's not really the Moon, but you get the idea.
The Moon isn't really changing shape, of course.
It's just a matter of your point of view.
As the Moon is traveling around the Earth, the Earth is traveling around the Sun at the same time, and that means different shadows are moving across the Moon.
That's what makes it look like it's changing shape.
[upbeat music] ♪ ♪ We call this the phases of the Moon.
The Earth travels around the Sun once a year, and the Moon is traveling around the Earth once a month.
As the Moon travels around the Earth, we sometimes see the side that's lit up by the Sun.
And other times, when the Moon's between the Earth and the Sun, we're looking at the part that's in shadow.
That's what makes it look like it's changing shape.
♪ ♪ So the next time someone tells you, "You're just going through a phase," just ask them which one-- half, full, quarter, crescent?
You get the idea.
♪ ♪ [laughing] This is my kind of basketball.
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