Download Day and Night - Effingham County Schools

Our Solar System
Day and Night
Phases of the Moon
Planets
Georgia Performance Standards
S4E2 Students will model the position and motion of
the earth in the solar system and will explain the role
of relative position and motion in determine
sequence of the phases of the moon.
a. Explain the day/night cycle of the earth using a model.
b. Explain the sequence of the phases of the moon.
c. Demonstrate the revolution of the earth around the
sun and the earth’s tilt to explain the seasonal changes.
d. Demonstrate the relative size and order from the sun
of the planets in the solar system.
Essential Questions
• Why are different phases of the Moon observed
throughout the month? What is the sequence of
those phases?
• What are the relative sizes of the planets in our
solar system?
• What is the relative order of the planets from the
Sun on our Solar System?
• While you are enjoying breakfast in
Georgia, night is falling in places half way
around the world.
• How can this be so?
CYCLE OF NIGHT AND DAY
• The cycle of night and day occurs because
the Earth rotates.
• To ROTATE means to turn on an axis.
• An AXIS is an imaginary line through the
center of an object. The Earth’s axis
passes through the North and South
poles.
• Remember that the Earth is a sphere. Only one
half of the Earth receives light and heat from the
Sun at any given time.
• The other half of the Earth is dark, and it is
nighttime there.
• Since the Earth rotates, the half that receives
light and the half that is dark changes positions
throughout the rotation of the Earth.
• As the day goes on, the Sun appears to
move across the sky.
• THE SUN IS NOT MOVING. Instead,
Earth is rotating, causing the Sun to look
like it is moving.
• As the Earth turns, the position of the Sun
in the sky changes, This causes the angle
at which sunlight strikes your part of the
Earth.
• The changing angle of sunlight causes
shadows to change throughout the day.
• When the Sun is low in the sky, shadows
are long. When the Sun is high in the sky,
shadows are short.
• Long ago, in ancient times, people used
the positions and lengths of shadows to
tell the time of day.
• Sundials can be used to tell the time of
day.
Earth’s Moon
• The Earth’s moon is a sphere made up of
rock.
• It revolves around Earth every 27 ½ Earth
days.
• The moon does not make its own light.
“Moonlight” is really sunlight reflecting
from the Moon’s surface.
MOON
• The rocky surface of the Moon is covered with
mountains, flat plains, and craters.
• A CRATER is a bowl shaped dent that is caused by an
object from space striking the surface of a planet or
moon.
• There is no air or liquid water on the Moon, which means
there are NO LIVING things.
• Daytime temperatures are much hotter on the Moon than
on Earth and nighttime temperatures are much colder.
MOON
• The Moon’s diameter (distance around) is
only about one-fourth of the Earth’s
diameter.
• The Moon is smaller than the Earth so its
gravity is weaker than the Earth’s gravity.
Because of this, things weigh less on the
Moon than they do on the Earth.
The same side of the moon always
faces the Earth.
If the same side of the moon
always faces the Earth, why
does the moon appear to
change shape?
As the moon revolves around the
Earth, the near side receives
different amounts of sunlight.
Phases of the moon
• The moon’s shape appears to change
from a crescent to a half circle, to a whole
circle, and back again.
• The changes are caused by the way
sunlight strikes the Moon as it revolves
around the Earth.
NEW MOON
• At one point during the moon’s revolution
around the Earth, it receives NO sunlight
and cannot be seen.
Crescent Moon
• As the moon revolves around the Earth, a
small part of the near side becomes sunlit
and can now be seen from the Earth.
Quarter Moon
• When the moon has revolved one quarter
of its orbit around the Earth, half of the
Moon’s near side can be seen from Earth.
Full Moon
• When the moon has revolved half way
around the Earth, the Moon’s entire near
side is sunlit and can be seen from Earth.
WAXING MOON
• After a new moon (when the moon is not
sunlit and you cannot see it), an increasing
amount of the Moon’s near side is sunlit.
WANING MOON
After a full moon (when the near side of the
moon is completely sunlit and you can see
it), a decreasing amount of the near side is
sunlit.
Seasonal Changes
• As the Earth orbits the Sun, the tilt of the
axis causes the seasons to change.
REVOLVE
• Remember that is takes one year for the
Earth to revolve around the Sun.
• REVOLVE means to move in a path
around another object.
• The orbit is in the shape of an ellipse. An
ELLISPE is a circle that is flattened and
slightly stretched out.
SEASONS
The four parts of the year---spring, summer, fall,
and winter.
In June, the Earth’s Northern Hemisphere (where
you live), is tilted toward the Sun. It receives
strong, direct sunlight, so it is summer here.
In December, the Earth tilts away from the Sun. It
receives weak, indirect sunlight and it is winter
here.
• Remember that the EQUATER is an
imaginary line the circles the Earth halfway
between the North and South Poles.
• It divides the Earth into NORTHERN and
SOUTHERN halves, called hemispheres.
Length of Day and Night
• The length of day and night changes throughout the
year. This is caused by the tilt of the Earth on its axis.
• Because the Earth is tilted towards the Sun in the
summer, there are more daylight hours and fewer hours
of darkness.
• In December, when the Earth is tilted away from the Sun
on its axis, there are more hours of darkness than
daylight hours. The shorter amount of sunlight is what
helps make winter colder than summer.
The Inner Planets
• Mercury, Venus, EARTH, and Mars are
called the INNER PLANETS.
• These planets get a lot of heat and light
because they are close to the Sun.
• The inner planets are small and are made
up of solid rock materials. There surfaces
have mountains and craters.
Inner Planets
Mercury
Venus
Earth
Mars
Mercury
• Is the closest planet to the Sun. It is very
hot during the day and very cold at night.
Venus
• Is the second planet from the Sun. It is
covered by thick clouds of gas. The clouds
trap the heat and make the planet very
hot.
Earth
• Is the third planet from the Sun. It is the
only planet known to support life. Earth
has an atmosphere.
Mars
• Is the fourth planet from the Sun. The
surface of Mars has many craters,
mountains, and volcanoes. Mars has the
largest volcano ever discovered in the
solar system.
THE OUTER PLANETS
• Jupiter, Saturn, Uranus, and Neptune are called
the outer planets. They are cold and dark
because they are far from the Sun. They are
large, made of gases, and have many moons.
Each also has a system of rings.
• Pluto was once known as the ninth planet. In
2006, astronomers classified it as a dwarf
planet. Pluto is smaller than any planet. It is
made of rocks and frozen gases. It has no rings
and only one moon.
Jupiter
• Is the fifth planet from the Sun and is the
largest planet. The Great Red Spot is a
large storm.
Saturn
• Is the sixth planet from the Sun. It has
beautiful rings made of dust, ice, and
rocks.
Uranus
• Is the seventh planet from the Sun. Unlike
any other planet, Uranus spins on its side.
Neptune
• Is the eighth planet from the Sun. Methane
in its atmosphere gives Neptune its blue
color.
Pluto
• Is now called a dwarf planet. It is smaller
than the planets, and very far from the
Sun.
Planets in Motion
• As it orbits the Sun, each planet spins like
a top. Earth’s day, one full spin, is 24
hours long. Some planets spin more
quickly than Earth, while others spin more
slowly. Jupiter spins around about every
10 hours. Venus takes 243 Earth days to
spin just once.
• The farther a planet is from the Sun, the
longer it takes to orbit. The time it takes to
complete one trip around the Sun is called
a YEAR.
• Earth’s year is about 365 days long.
Mercury makes a complete orbit in just 88
days. Neptune takes about 165 Earth
years to complete its orbit around the Sun.
• For thousands of years, people have been
observing the Sun, the Moon, and other
objects in the sky.
• Scientists did not learn how these objects
move until a few hundred years ago.
• Why do you think they took so long?
Essential Questions
• Why are different phases of the Moon observed
throughout the month? What is the sequence of
those phases?
• What are the relative sizes of the planets in our
solar system?
• What is the relative order of the planets from the
Sun on our Solar System?