Earth, Moon, and Sun Study Guide KEY
Use this sheet to check your answers for accuracy. Answers do not need to be wordfor-word the same. However, important details should be included.
1. What is the cause of Earth’s seasons? The seasons are caused by changes in the amount
of solar energy a place receives throughout the year.
2. The amount of solar energy Earth receives depends on what two things:
(1) Amount of sunlight received (longer/shorter days) and (2) the angle of impact
(direct/indirect impact of light)
3. Explain how the angle of impact of the Sun’s light upon the surface of the Earth affects the
temperature of Earth’s surface. (What happens if the angle is steep? Direct?)
If sunlight hits Earth at a direct angle, the energy is concentrated in a smaller area, so the
temperature is warmer. If the angle is steeper, the energy is spread out over a larger area so
the temperature is cooler.
4. How is Earth’s axis pointed relative to the sun during our winter? It’s pointed away
How does this affect the angle of impact and amount of sunlight received at that time?
The Northern Hemisphere gets less direct sunlight (it hits at a steeper angle) and has
shorter days (it gets less sunlight)
5. How is Earth’s axis pointed relative to the sun during our summer? It’s pointed towards it
How does this affect the angle of impact and amount of sunlight received at that time?
The Northern Hemisphere gets more direct sunlight (it hits at a more direct angle) and has
longer days (it gets more sunlight)
Spring
Position 4
6. Add the following items to the diagram:
-Label the diagram with the seasons that occur
in Northern Hemisphere;
Summer
-Draw in arrows that show the direction of
revolution around the sun;
-Add the equator to each “Earth”;
X
Winter
X
Tropic of
Cancer
X
Tropic of
Capricorn
Position 1
Position 3
-Draw and label the Tropic of Cancer.
X
-Draw and label the Tropic of Capricorn.
Fall
Position 2
7. How much of the moon’s surface is always lit by the sun? Half is always lit.
8. Why does the Moon’s shape that we see seem to change? The “shape” that we see
depends on how much of the sunlit part of the moon is facing Earth. (The amount of the lit
part that we can see changes as the moon revolves around the Earth.)
9. Why do we always see the same side of the moon? (HINT: Look at the revolution/rotation
periods.) Because the moon’s rate of rotation and revolution are the same (29.5 days), the
moon always keeps the same side towards the Earth.
10. What is causing the darkness of a “New Moon”? A new moon is caused when the lit half
of the moon is on the far side, facing away from Earth.
11. Write the phase of the moon someone on Earth would see when the moon is at each
position:
A. Full Moon
B. Last/3rd Quarter
C. Waning Crescent
D. New Moon
E. 1st Quarter
F. Waxing Gibbous
E
F
A
D
B
C
12. Explain the role that gravity plays in Earth’s tides. (Tell why there are two high tides and
two low tides at any time on Earth.)
Gravity pulls the water on Earth towards the Moon, causing a high tide on the side towards
the moon. The Earth also gets pulled towards the moon, leaving some water behind (due to
inertia and lower gravitational pull), which causes a second high tide on the side away from
the Moon.
13. What is a “spring tide”? It is when the moon, sun, and Earth are in a straight line; it is the
highest possible high tide
14. What is a “neap tide”? It’s when the moon, sun, and Earth form a right angle; it is the
lowest possible high tide.
15. Add the letter “S” to the diagram to show the
position(s) of the moon during a spring tide.
Add the letter “N” the diagram to show the position(s)
of the moon during a neap tide.
N
S
S
N
16. How is a solar eclipse different from a lunar eclipse? Any reasonable answer. May
include: lunar eclipses are visible over a large area, but solar eclipses can only be seen
from a small path on Earth’s surface; Solar eclipses are where the moon covers the sun,
blocking its light, and lunar eclipses are when the moon moves into Earth’s shadow.
17. Add the letter “S” to the diagram to show the position
of the moon during a solar eclipse.
Add the letter “L” to the diagram to show the position
of the moon during a lunar eclipse.
S
L