Moon Phases

Essential Question What pattern of change do we see in the appearance of the moon and what are the phases of the moon?

I Can Statements: I can define orbit and reflection. I can describe changes in the appearance of the moon during a month. I can identify the pattern of change in the moon’s appearance.

What is an orbit? Orbit: The path the earth follows as it revolves around the sun. Helpful Hint: Earth’s orbit is an ellipse, or a slightly elongated circle.

Why does the moon shine? The moon reflects the light of the Sun. Reflection: Light from the sun bounces off the moon’s surface. Helpful Hint: A mirror reflects an image because light bounces off of it surface.

Half of the Moon is always lit up by the sun. As the Moon orbits the Earth, we see different parts of the lighted area.

The revolution of the Moon around the Earth makes the Moon look as if it is changing shape in the sky. But the moon never changes its shape.

This is caused by the different angles from which we see the lighted part of the Moon's surface. These are called "phases" of the Moon.

Phases of the Moon Phases of the Moon: different angles from which we see the lighted part of the Moon's surface. Helpful Hint: There are 8 different phases.

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The Moon passes through eight phases during a cycle that repeats itself approximately every 28 days. The phases always follow one another in the same order: New moon Waxing Crescent First quarter Waxing Gibbous Full Moon Waning Gibbous Last Quarter Waning Crescent

New Moon The lighted side of the Moon faces away from the Earth. The moon is almost directly between the sun and Earth. Start of the Moon Cycle. Looks very dark, so we often see nothing in the sky.

New Moon

Waxing Crescent Moon This Moon can be seen after the New Moon, but before the First Quarter Moon. A bit of the sunlit side of the moon shows. The crescent will grow larger and larger every day, until the Moon looks like the First Quarter Moon. ("Waxing" means increasing, or growing larger.) - Vocab. Sheet

Waxing Crescent Moon

First Quarter Moon The moon is a quarter of its way around earth. It is in its first quarter. The right half of the Moon appears lighted and the left side of the Moon appears dark. During the time between the New Moon and the First Quarter Moon, the part of the Moon that appears lighted gets larger and larger every day, and will continue to grow until the Full Moon.

First Quarter Moon

Waxing Gibbous Moon The moon is waxing, which means increasing, or growing larger. Moon can be seen after the First Quarter Moon, but before the Full Moon. Gibbous means: Greater than half, but not full. The amount of the Moon that we can see will grow larger and larger every day. ("Waxing" means increasing, or growing larger.)

Waxing Gibbous Moon

Full Moon Two weeks have passed since the new moon. The entire face of the moon we see shines. The lighted side of the Moon faces the Earth. The Moon that we see is very bright from the sunlight reflecting off it. This means that the Earth, Sun, and Moon are nearly in a straight line, with the Earth in the middle.

Full Moon

Waning Gibbous Moon This Moon can be seen after the Full Moon, but before the Last Quarter Moon. Gibbous means more than half, but not full. The amount of the Moon that we can see will grow smaller and smaller every day. ("Waning" means decreasing, or growing smaller.)

Waning Gibbous Moon

Last Quarter Moon Sometimes called Third Quarter. The left half of the Moon appears lighted, and the right side of the Moon appears dark. The moon is three-quarters of its way around the Earth. It is in its last quarter phase. During the time between the Full Moon and the Last Quarter Moon, the part of the Moon that appears lighted gets smaller and smaller every day. It will continue to shrink until the New Moon, when the cycle starts all over again.

Last (Third) Quarter Moon

Waning Crescent Moon A bit of the waning sunlit side of the moon shows. ("Waning" means decreasing, or growing smaller.) This Moon can be seen after the Last Quarter Moon and before the New Moon. The crescent will grow smaller and smaller every day, until the Moon looks like the New Moon.

Waning Crescent Moon

Waxing & Waning

Tips to Remember Waxing and Waning Flatten your right hand, with your fingers together and your thumb sticking out. Hold your hand out at arm’s length in front of you. Tilt your thumb towards the ground. See how the line along your thumb and first finger makes a curve, roughly like a backwards letter “‘C’”? It actually looks sort of like this: ) This is the shape of the Waxing Moon. If the Moon’s curve fits along this right-hand curve, it is a Waxing Moon. Commit it to memory. One way to remember this is to think of drawing in wax. Most people are right-handed, and if they were to draw in wax, they’d use their right hand. So if the Moon fits in your right-hand curve, it is waxing. Say: “Wax on” Do the same with the left hand. This makes a shape like this: ( This is the shape of the Waning Moon. If the moon fits in this curve, you know it is getting smaller every day, going toward the new moon / dark moon. Say: “Wane Off”

Moon Movie The movie is an animated GIF created by Antonio Cidadao from a sequence of still images taken during March and April 1998.

MOON QUIZ!! ld/solar_system_level2/moonlight.html