4.1
Why does the appearance of the Moon change over time?
Half of the Moon is almost always illuminated. As the Moon revolves around Earth, we see only portions of the illuminated side, depending on the Moon's position relative to Earth.
As seen from space, how much of the Moon reflects sunlight at each position as the Moon orbits Earth?
The Sun illuminates about half of the Moon's surface at any given time.
Which vocab term means:to light up
illuminate
What role does the Sun have in the occurrence of the Moon’s phases?
The Sun illuminates half of the Moon, allowing us to view the Moon and its phases from Earth.
How can you determine if the Moon is waxing or waning during its lunar cycle?
Look at which side the illuminated hump is on. If it is on the right, the Moon is waxing and if it is on the left, the Moon is waning.
When a moon is waxing, what is it doing?
The light is growing on the right.
Draw a model to describe the relative positions of the Sun, Earth, and Moon: During a new moon. During a full moon. Label each.
New Moon: Sun---Moon---Earth
Full Moon: Sun---Earth---Moon
Why does the same side of the Moon always face Earth?
The rotational period is the same as its orbital period. This slower rotation, compared to Earth’s, keeps the same side of the Moon facing Earth.
When a moon is waning, what is it doing?
The light is shrinking on the left side of the moon.
The far side of the Moon is sometimes referred to as the dark side of the Moon.
Is the far side always dark? Explain your answer using evidence from your investigation.
Claim: No, the dark side of the moon reflects just as much sunlight as the near side while the Moon orbits Earth.
Why do patterns in the Moon’s appearance occur?
Half of the Moon is illuminated by the Sun at all times. As the Moon orbits Earth, different illuminated portions of the Moon become visible from Earth. These predictable, cyclic patterns are referred to as lunar phases.
What do we see during a new moon?
No Moon
What role does the Sun have in the cyclic pattern of lunar phases?
The Sun illuminates half of the Moon at all times. Any portion of the illuminated side that faces Earth can be seen.
Your brother states that the Moon makes its own light, which is why we can see it in the night sky. Using your investigations and information from the readings, make an evidence-based argument that either supports or refutes your brother’s claim.
Arguments should refute the brother’s claim and include information about how the Moon is illuminated in the sky because sunlight is reflected off the Moon’s surface. Students should be able to reference observations and readings from Investigations 4.1 and 4.2.
Claim: My brother's statement is incorrect.
Evidence: Based on investigations 4.1 and 4.2, the Sun is what produces the light we see on the Moon.Reasoning: Since the Sun illuminates the Moon, my brother's statement that the Moon produces its own light is not accurate.
What is the far side of the moon?
The side we can't see because it is facing away from us.