Download Chapter 12 Earth, Moon, and Sun The Moon`s Surface

Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
1. What is the source of most of Earth’s heat and natural light?
a. the moon
b. Earth itself
c. the sun
d. stars other than the sun
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
1. What is the source of most of Earth’s heat and natural light?
a. the moon
b. Earth itself
c. the sun
d. stars other than the sun
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
2. What force keeps Earth in motion around the sun?
a. friction between Earth and the planets
b. gravity between Earth and the moon
c. friction between Earth and the sun
d. gravity between Earth and the sun
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
2. What force keeps Earth in motion around the sun?
a. friction between Earth and the planets
b. gravity between Earth and the moon
c. friction between Earth and the sun
d. gravity between Earth and the sun
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
3. How many natural satellites does Earth have?
a. one
b. two
c. six
d. dozens
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
3. How many natural satellites does Earth have?
a. one
b. two
c. six
d. dozens
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
4. What causes day and night?
a. the tilt of Earth’s axis
b. the sun moving behind the moon
c. Earth’s movement around the sun
d. Earth’s rotation on its axis
Chapter 12 Earth, Moon, and Sun
Chapter Preview Questions
4. What causes day and night?
a. the tilt of Earth’s axis
b. the sun moving behind the moon
c. Earth’s movement around the sun
d. Earth’s rotation on its axis
Chapter 12 Earth, Moon, and Sun
What events are caused by the motion of Earth
and the moon?
Imagine that you are looking up at
a full moon in the sky. Why is the
moon so bright? Does the moon
produce its own light, like a
flashlight, or does its light come
from somewhere else? Explain
your reasoning.
Chapter 12 Earth, Moon, and Sun
Section 1: Earth in Space
Standard 8.4.e: Students know the appearance,
general composition, relative position and size,
and motion of objects in the solar system,
including planets, planetary satellites, comets,
and asteroids.
Chapter 12 Earth, Moon, and Sun
How Earth Moves
How doe Earth move
in space?
Rotation
Revolution
Earth moves through space in two
major ways: rotation and revolution.
Earth rotates on its axis every 24
hours, causing day and night.
Earth revolves around the Sun in a
cycle of about 365.25 days. The
modern calendar compensates for the
one-fourth day by adding a day every
four years. We call this a “leap year.”
Chapter 12 Earth, Moon, and Sun
Sunlight Striking Earth’s Surface
Near the equator, sunlight strikes Earth’s surface more
directly and is less spread out than near the poles.
Chapter 12 Earth, Moon, and Sun
Earth’s Tilted Axis
What causes the cycle of
seasons on Earth?
Earth has seasons because its
axis is tilted as it revolves
around the sun.
Earth’s axis is tilted 23.5
degrees relative to the Sun. The
globe has imaginary lines
delineated 23.5 degrees from
the Equator to identify the areas
of most direct sunlight in the
Northern and Southern
Hemispheres.
Chapter 12 Earth, Moon, and Sun
Earth’s Tilted Axis
• Located at 23.5 degrees north
latitude.
• Summer occurs in the Northern
Hemisphere when this imaginary
line is in direct alignment to the
Sun in late
.
• Located 23.5 degrees south
latitude.
• Summer occurs in the Southern
Hemisphere when this imaginary
line is in direct alignment to the
Sun in late
Chapter 12 Earth, Moon, and Sun
Seasons on Earth
Earth has seasons because its axis is tilted as it revolves
around the sun.
Chapter 12 Earth, Moon, and Sun
Seasons on Earth
The height of the sun above the horizon varies with the
season.
Chapter 12 Earth, Moon, and Sun
Section 2: Gravity and Motion
Standard 8.2.f: Students know the role of gravity in
forming and maintaining the shapes of planets,
stars, and the solar system.
Chapter 12 Earth, Moon, and Sun
Gravity, Mass, and Distance
The strength of the force of gravity between two objects
depends on two factors: the masses of the objects and the
distance between them.
Chapter 12 Earth, Moon, and Sun
Gravity Versus Distance
As a rocket leaves a planet’s
surface, the force of gravity
between the rocket and the
planet changes. Use the graph
to answer the following
questions.
Chapter 12 Earth, Moon, and Sun
Gravity Versus Distance
Reading Graphs:
What is the force of gravity on
the rocket at the planet’s
surface?
Four million newtons
Chapter 12 Earth, Moon, and Sun
Gravity Versus Distance
Reading Graphs:
What is the force of gravity on
the rocket at a distance of two
units (twice the planet’s
radius from its center)?
One million newtons
Chapter 12 Earth, Moon, and Sun
Gravity Versus Distance
Making Generalizations:
According to the graph, is the
relationship between gravity
and distance linear or
nonlinear? Explain.
Nonlinear. The graph is a
curve.
Chapter 12 Earth, Moon, and Sun
Gravity Versus Distance
Drawing Conclusions:
In general, how does the
force of gravity pulling on the
rocket change as the distance
between it and the planet
increases?
It decreases.
Chapter 12 Earth, Moon, and Sun
Gravity Versus Distance
Predicting:
What would the force of
gravity on the rocket be at a
distance of five units?
0.16 million newtons, or
160,000 newtons
Chapter 12 Earth, Moon, and Sun
Gravity and Inertia
Newton concluded that two factors–inertia and gravity–
combine to keep Earth in orbit around the sun and the moon
in orbit around Earth.
Chapter 12 Earth, Moon, and Sun
Section 3: Phases, Eclipses, and Tides
Standard 8.2.g Students know the role of gravity in
forming and maintaining the shapes of planets,
stars, and the solar system.
Standard 8.4.d Students know that stars are the
source of light for all bright objects in outer space
and that the Moon and planets shine by reflected
sunlight, not by their own light.
Chapter 12 Earth, Moon, and Sun
Motions of the Moon
The changing relative positions of the moon, Earth, and sun
cause the phases of the moon, eclipses, and tides.
Chapter 12 Earth, Moon, and Sun
Phases of the Moon
The phase of the moon you see depends on how much of
the sunlit side of the moon faces Earth.
Chapter 12 Earth, Moon, and Sun
The Moon’s Orbit
The moon’s orbit is tilted about 5 degrees relative to Earth’s
orbit around the sun.
Chapter 12 Earth, Moon, and Sun
Solar Eclipse
A solar eclipse occurs when the moon passes directly between
Earth and the sun, blocking sunlight from Earth.
Chapter 12 Earth, Moon, and Sun
Lunar Eclipse
During a lunar eclipse, Earth blocks sunlight from
reaching the moon’s surface.
Chapter 12 Earth, Moon, and Sun
Tides
Tides occur mainly because of differences in the force of
gravity between the moon and different parts of Earth.
Chapter 12 Earth, Moon, and Sun
Spring and Neap Tides
When Earth, the sun, and the moon are in a straight line, a
spring tide occurs. When the moon is at a right angle to the
sun, a neap tide occurs.
Chapter 12 Earth, Moon, and Sun
Section 4: Earth’s Moon
Standard 8.4.e Students know the appearance,
general composition, relative position and size, and
motion of objects in the solar system, including
planets, planetary satellites, comets, and asteroids.
Chapter 12 Earth, Moon, and Sun
The Moon’s Surface
What features are
found on the moon’s
surface?
•The moon’s surface has dark, flat areas,
which Galileo called maria.
•These “seas” are actually hardened rock
from huge lava flows that occurred
between 3 and 4 billion years ago.
•The moon’s surface contains large
round pits called craters.
•Craters can be hundreds of kilometers
across.
•They were caused by impacts of
meteoroids early in its history.
•A third major feature of the moon
surface is the presence of highlands, or
mountains.
Chapter 12 Earth, Moon, and Sun
The Moon’s Surface
Features on the moon’s surface include maria, craters, and
highlands.
Chapter 12 Earth, Moon, and Sun
Characteristics of the Moon
•The moon is 3,476 km in diameter, a
little less than the distance across the
contiguous United States.
•It is about one-fourth the diameter of
Earth.
•The moon has only one-eightieth the
mass of Earth.
•Temperatures range from 130°C in
direct sunlight to -180°C at night.
•Temperatures vary so much
because it has no atmosphere.
•The moon has no liquid water.
Chapter 12 Earth, Moon, and Sun
The Origin of the Moon
Scientists theorize that a planet-sized object collided with
earth to form the moon.