Moon Phases Study Guide

Why do we only see one side of the Moon?

• The Moon does not rotate on its axis.

• The Moon's rotation period matches its orbit around Earth.

• The Moon is always facing the Sun.

• The Earth's shadow covers the other side.

What are Moon phases? Why does the Moon appear to change its phase when viewed by an observer on Earth?

• The Moon has its own light source that changes over time.

• The Earth's shadow falls on the Moon, causing the phases.

• The Moon's position relative to the Earth and Sun causes the phases.

• The Moon's surface changes shape, creating different phases.

Would you see changing phases of the Moon if you were in space hovering above the Earth watching the Moon revolve?

• Yes, you would see changing phases.

• No, the Moon would always look the same.

• The Moon would appear to change color.

• The Moon would disappear completely.

The Moon produces its own light.

• True

• False

How much of the Moon is always illuminated by sunlight?

• Half of the Moon

• The entire Moon

• One quarter of the Moon

• None of the Moon

Which of the following is a phase of the Moon?

• Full Moon

• Half Moon

• Quarter Moon

• New Moon

Which Moon phases technically occur in an instant? (Your eye may see them last for days - but they actually only happen in an instant.) Which phases are the transition phases, which last for more than one day?

• First Quarter

• Waxing Crescent

• Full Moon

• New Moon

• Last Quarter

What does waxing mean? What does waning mean? How can you tell, just by looking at the Moon, if it is waxing or waning?

• Waxing refers to the phase of the Moon when it is increasing in illumination.

• Waning refers to the phase of the Moon when it is decreasing in illumination.

• You can tell if the Moon is waxing or waning by observing its shape and the amount of light it reflects.

Be able to infer the Moon's phase visible to an observer on Earth when given a diagram of an aerial view of the Moon as it orbits the Earth.

• New Moon

• First Quarter

• Full Moon

• Last Quarter

What is a sidereal month?

• The time it takes for the Moon to return to the same position among the stars

• The time it takes for the Moon to complete one orbit around the Earth

• The time it takes for the Moon to go from new moon to new moon

• The time it takes for the Earth to orbit the Sun