Download Sun, Moon, and Earth presentation

The Sun-Earth-Moon
System
Ms. Barry
Earth and the Universe
▶
Earth is one of eight
planets that orbit the
Sun.
▶
The Sun is one of
billions of stars that
make up the Milky
Way galaxy.
▶
The Milky Way is one
of billions of galaxies
in the universe.
The Scale of the Solar System
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The Sun is 100x wider than Earth and 10x wider
than the planet Jupiter.
The Sun and Jupiter are the two largest objects
in the solar system.
Motions of the Earth
▶ Earth’s orbit is nearly round, or elliptical.
▶ The orbit of an object around another object is
revolution.
▶ It takes Earth 365.25 days, or one year, to revolve
around the Sun once.
Measuring Distance
▶
An astronomical unit (AU) can be used to
measure distances to objects in the solar
system.
▶
An AU is the average
distance between
Earth and the Sun,
approximately
150 million km.
Day and Night
▶
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Rotation is the spin of an
object around its axis.
Earth spins, or rotates,
on its axis like a top.
Earth’s rotation causes day
and night.
The side of Earth facing the
Sun is in daylight. The side
of Earth away from the Sun
is in darkness.
Earth makes one full
rotation every 24 hours.
The Moon
▶ Gravity holds the Moon in orbit around Earth.
▶ ¼ the size of the earth
▶ The Moon rotates on its axis, and revolves
around Earth, orbiting Earth once every 27.3
days.
▶ Because the Moon
revolves and rotates
in the same amount
of time, the same
side of the Moon
always faces Earth.
The Phases of the Moon
▶
The Moon is visible
because it reflects
sunlight.
▶
The Moon completes a
cycle of phases every
29.5 days.
▶ The moon’s axis is
tilted, so it is not
usually blocked by the
earth
Eclipses
▶ An eclipse is the movement of one
solar system object into the shadow of
another object.
Solar Eclipse
▶ During a solar eclipse, a small part of
Earth is in the Moon’s shadow.
▶ The Moon appears to completely or
partially cover the Sun.
▶ This can only occur during a new moon
Lunar Eclipse
▶
During a lunar eclipse, Earth’s shadow
completely or partially covers the Moon.
▶
This can only happen during a full moon
Earth’s Tilt and Seasons
▶
Seasons occur because Earth’s tilt
does not change as Earth orbits the
Sun.
Summer and Winter
▶ When the northern hemisphere is tipped toward
the sun, it experiences summer
▶ Sunlight is more intense
▶ When the northern hemisphere is tipped away
from the sun, it experiences winter
▶ Sunlight is less intense
Tides
▶ Tides are the rise and fall of the oceans caused by
the gravitational force between Earth, Moon, and
Sun.
▶ The Moon has more influence on tides than the
Sun because it is closer to Earth than the Sun.
Spring Tides
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Caused by the extra gravitational pull
from the moon and sun when they are all
in line
High tides are higher than usual.
Occur during full moon and new moon
phases.
Neap Tides
▶
The gravitational pull of the Moon is
perpendicular to the gravitational pull of
the Sun.
▶
High tides are lower than usual
▶
Occur during first and third quarter moons
Equinox
▶ An equinox occurs when the sun is shining
directly at the equator
▶
Occurs twice each year. These two days
signify the beginning of spring and fall.
Solstice
• A solstice occurs when the Earth’s rotation axis is
tilted directly toward or away from the Sun
• North Pole is toward the Sun = summer in the
northern hemisphere.
• South Pole is toward the Sun = winter in the
northern hemisphere.