Phases, Eclipses and Tides

Question

This section explains what causes the phases of the moon, what causes eclipses, and what causes tides.

Target Reading Skills:

Look at the Figure “Phases of the Moon” in the text. In the graphic organizer below, write the answers to bth questions as you read.

Q: Why does the moon have phases?
A:
The changing relative positions of the moon, Earth, and sun cause the phases of the moon, eclipses, and tides.
Q: Do we see different sides of the moon as the phases of the moon appear?
A:
No we don't see different sides of the moon.

Motions of the Moon

Highlight each statement that is true about the motions of the moon.

The moon revolves around the Earth once a year.
The same side of the moon always faces Earth.
The moon rotates slowly on its axis once every 27.3 days.
A “day” and a “year” on the moon are the same length.

What causes the phases of the moon, eclipses, and tides?

Phases of the Moon

The different shapes of the moon you see from Earth are called

How often does the moon go through an entire set of phases?

What does the phase of the moon you see depend on?

Complete the table to show what you see during different phases of the moon.
Phases of the Moon
Phase
What You See
New Moon
The side of the moon facing the Earth is dark.
First Quarter
a.
Full Moon
b.
Third Quarter
c.

Is the near side (facing Earth) always the dark side? Use the table to support your answer.

What percentage of the dark side of the moon do you see during the first and third quarters?

Eclipses

When the moon’s shadow hits Earth or Earth’s shadow hits the moon what occurs?

What are the two types of eclipses?
1.
2.

The darkest part of the moon’s shadow is called the

What causes a solar eclipse?

The larger part of a shadow, less dark than the umbra, is called the

Highlight each statement that is true about solar eclipses.
People in the umbra see only a partial solar eclipse.
During a partial solar eclipse, part of the sun remains visible.
During a total solar eclipse, the sky grows dark.
People in the penumbra see a total solar eclipse.

What is the arrangement of Earth, the moon , and the sun during a lunar eclipse?

Highlight each statement that is true about lunar eclipses.
People in Earth’s umbra see a total lunar eclipse.
A lunar eclipse always occurs at a full moon.
During a lunar eclipse, Earth blocks sunlight from reaching the moon.
A partial lunar eclipse occurs when the moon passes partly into the umbra of Earth’s shadow.
Tides

The rise and fall of ocean water are called

What force pulls the moon and Earth toward each other?

Why do tides occur?

Highlight each statement that is true about lunar eclipses.
The point on Earth that is closest to the moon has a high tide.
Every location on Earth has two high tides per month.
A low tide occurs at the point on Earth farthest from the moon.
The point on Earth farthest from the moon has a high tide.

What is a spring tide?

What is a neap tide?