Download Solar System

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Sun- center and largest body of solar system
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Eight planets and their moons revolve around
the sun
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Comets- smaller bodies
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Asteroids- chunks of rocks
Comets and asteroids revolve around the sun
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Revolve: travel around
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Orbit: path
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Gravity: pull that holds the bodies of the solar
system together
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Ellipse: oval path that a planet orbits
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Is an average sized star
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Sun and its solar system are part of the Milky
Way galaxy
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Composed of hydrogen and helium gases
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Has sunspots- dark spots that appear on the
surface
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Has solar flares- violent bursts of energy from
the surface
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Solar flares can cause auroras- spectacular
light shows
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Galaxy- huge system of stars, dust, and gas
held together by gravity
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Majority of galaxies are spiral galaxies
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Other types:
 Elliptical
 Irregular
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Constellation- group of stars that forms a
pattern
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Knowing which constellation a star is in lets
you know which part of the sky to look at to
find that star
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Stars appear to move across the sky just like the
sun because of the Earth’s rotation
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Some constellations can only be seen during
certain times of the year
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Constellations change with the seasons because
Earth is traveling around the sun
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Everything in the universe moves- stars move in
various directions and at various speeds
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Earth rotates on its axis
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Axis- imaginary line between the North and
South Poles and the Earth’s center
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Rotates from west to east
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Earths rotation causes daytime and nighttime
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A day is a complete rotation and takes 24
hours
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Time is based on Earth’s rotation
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Earth is divided into 24 time zones
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Earth’s moon takes about 28 days to revolve
around Earth- we only see one side of moon
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Earth’s axis is tilted- this causes axis to be
pointed toward the sun during parts of orbit,
and away from sun during other parts
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Earth takes 365 and a fourth days (one year)
to orbit once around the sun
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During the year, the Northern and Southern
Hemispheres experience seasons
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Seasons- change in the number of daylight
hours and average daily temperatures
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December 21- Northern Hemisphere has
fewest daylight hours
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June 21- Northern Hemisphere has most
daylight hours
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The side of Earth facing the sun gets more
direct sunlight- Northern Hemisphere gets
the most solar energy during the summer
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Southern Hemisphere has opposite seasons
as Northern Hemisphere
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Eight planets revolve around sun in elliptical
orbits
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Order from sun outward: Mercury, Venus,
Earth, Mars, Jupiter, Saturn, Uranus, and
Neptune
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Four planets closest to the sun: Mercury,
Venus, Earth, and Mars
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Much smaller than outer planets
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Have solid rocky surfaces with mountains,
plains, canyons, and craters
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Four planets that are furthest from Sun
starting after Mars
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Jupiter, Saturn, Uranus, and Neptune
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Very large and made of gases
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They are often called gas giants
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Have no solid surface
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Jupiter- banded appearance and large red
spot
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Saturn- ring system
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Uranus- blue color and rotates on side
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Neptune- appears blue
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Asteroid belt- lies in the space between the
inner planets and outer planets
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Asteroids orbit sun in same area
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Moon does not give off light, it reflects sun’s
light
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Changing of the moon’s shape during the
month is the moon’s phases
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As moon moves through its orbit, its position
is sky changes relative to the positions of the
sun and moon
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The portion of the sunlit side of the moon
changes during the month
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Full moon- round circle- when Earth I
between the moon and the sun
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Waning moon- grows smaller
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New moon- cannot see- sunlit side facing
away from Earth
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Waxing moon- seems to grow larger
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Eclipse: one thing in space blocks the view of
another
 Solar eclipse: moon passes between the sun and
Earth- blocks view of the sun
 Lunar eclipse: Earth comes between the moon
and sun- casts a shadow on the moon
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Moon:
 surface has plains, mountain ranges, valleys, and
craters
▪ Craters- formed when objects from space hit the moon’s
surface
 No running water/no atmosphere
 No weathering/erosion/earthquakes/volcanoes
 Surface changes from being hit by objects from
space
 Rotation(length of day): almost 28 Earth days
 Revolution(Length of year): Almost 28 Earth days
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Earth:
 Has liquid water
 Surface has plains, mountain ranges, valleys, and
few craters
 Has earthquakes/erosion/volcanoes
 Has atmosphere to burn up objects from space
before they hit Earth and form craters
 Rotation (length of day): Almost 24 hours
 Revolution ( length of year): 365 and ¼ days