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Our Solar
System
By Julie Bingaman
5th Grade

DID YOU KNOW?
 Our Solar System is made up of eight planets, their moons,
and our sun. The planets and their moons revolve around,
or orbit the sun.
The orbits are not round. They are elliptical ( E-lip-tih-cul).
Elliptical means egg-shaped.
The first four planets are called the inner planets. They are
closest to the sun. Their names are Mercury, Venus, Earth
and Mars. These planets are made mostly of rock.
The next four planets are called the outer planets. Saturn,
Jupiter, Uranus and Neptune are called gas giants because
they are made mostly of gases.

The Source
• The Sun is the most prominent
feature in our solar system. It
is the largest object and
contains approximately 98% of
the total solar system mass
• The Sun is the star at the
center of the Solar System
• The Sun's color is white,
although from the surface of
the Earth it may appear yellow
because of atmospheric
scattering of blue light
• designated a yellow star,
because its visible radiation is
most intense in the yellow-
green portion of the spectrum

Inner Planets
•The inner planets are Mercury, Venus, Earth, and Mars.
•Close to the Sun and separated from the much larger Outer Planets by an
asteroid belt.
•Sometimes called terrestrial planets and are composed of rock.
•Due to their hard surfaces, these planets have canyons, craters, mountains,
and volcanoes.
•Few or no moons.
•Developed from small grains of dust that collided and formed together.

Mercury
• Closest planet to the sun
• 2nd smallest planet in the
solar system
• The surface is similar to that
of Earth’s moon
• Virtually has no atmosphere
• Mercury rotates 1 ½ times
during each orbit
• 1 day on Mercury=176
Earth days
• Small magnetic field, which
means there are no
satellites

Venus
• 2nd Planet from the sun
• Brightest object in the sky
except for the sun and moon
• 1 Venus day= 243 Earth days
• Regarded as Earth’s sister
planet
• Some ways similar to Earth,
only slightly smaller
• Atmosphere is made up most
of Carbon Dioxide
• No magnetic field, which
means it has no satellites
(moons)

Earth
• 3rd planet from the sun
• 5th largest planet in the solar
system
• 71 Percent of the Earth's
surface is covered with water.
• Only planet on which water
can exist in liquid form on the
surface
• The Earth's magnetic field and
its interaction with the solar
wind also produce the Van
Allen radiation belts
• Has one natural satellite called
the moon

Mars
• 4th planet from the sun
• 7th largest in the solar system
• Referred to as the Red planet
• Most favorable place in the Solar
System (other than Earth)
• Mars' orbit is significantly elliptical
• Though Mars is much smaller than
Earth, its surface area is about the
same as the land surface area of
Earth
• Weak magnetic fields exist in various
regions of Mars
• When it is in the nighttime sky, Mars
is easily visible with the unaided eye
• Mars has two tiny satellites called
Phobos and Deimos

Outer Planets
•The outer planets are Jupiter, Saturn, Uranus, and Neptune.
•Located outside of the asteroid belt.
•These planets are much larger than the inner planets and are called gas giants as
they are composed primarily of hydrogen and helium.
•No solid surface. The hydrogen and helium are in gas form in the atmosphere and
below that in a liquid state.
•Each has many moons and rings.

Jupiter
• Jupiter is the fifth planet from the
Sun and by far the largest.
• Jupiter is more than twice as
massive as all the other planets
combined (the mass of Jupiter is
318 times that of Earth).
• Jupiter is the fourth brightest
object in the sky (after the Sun,
the Moon and Venus).
• Jupiter has 63 known satellites
(as of Feb 2004): the four large
Galilean moons plus many more
small ones
• Jupiter has rings like Saturn's, but
much fainter and smaller

Saturn
• Saturn is the sixth planet from
the Sun and the second largest
• Saturn has 53 named satellites
• Saturn is the least dense of the
planets; its specific gravity (0.7) is
less than that of water.
• Saturn's rings are extraordinarily
thin, there are two prominent
rings (A and B) and one faint ring
(C) can be seen from the Earth
• In the nighttime sky, Saturn is
easily visible to the unaided eye
• Like the other Jovian planets,
Saturn has a significant magnetic
field.

Uranus
• Uranus is the 7th planet from
the sun and the third largest
• Most of the planets spin on
an axis nearly perpendicular to
the plane of the ecliptic but
Uranus' axis is almost parallel
to the ecliptic
• Primarily composed of rock
and various ices
• Uranus' blue color is the result
of absorption of red light by
methane in the upper
atmosphere
• Uranus has 11 known rings
• Uranus has 27 named moons

Neptune
• Neptune is the eighth planet from
the Sun and the fourth largest
• Neptune's blue color is largely the
result of absorption of red light by
methane in the atmosphere but
there is some additional as-yet-
unidentified chromophore which
gives the clouds their rich blue tint.
• Little is still know of Neptune
because there has only been one visit
of a spacecraft there
• Neptune's winds are the fastest in
the solar system, reaching 2000
km/hour.
• Neptune's rings are very dark but
their composition is unknown.
• Neptune has 13 known moons; 7
small named ones

Guess What?
• Pluto was once a part of
our solar system
• In 2006 scientist found 2
other “planets” in our
solar system that were
thought to be the moons
of Neptune. Since they
were bigger than Pluto,
scientists decided to take
Pluto out of the solar
system
• It is now called a Dwarf
planet

Pluto
• Pluto orbits beyond the
orbit of Neptune (usually).
• It is smaller than many
moons, therefore it is now
called a Dwarf Planet
• A spacecraft has never
visited Pluto
• Pluto rotates in the
opposite direction from
most of the other planets.
• Charon ( "KAIR en" ) is
Pluto's largest satellite:

Here’s the thing about moons
• Did you know?
It is a combination of
the amount of
gravitational pull and
the size of the planet as
to why some planets
have more moons than
others! Remember a
moon is a satellite, it
orbits around its’ host
planet.
• Which planets have
moons?
• Earth (1)
• Mars (2)
• Jupiter (63)
• Saturn(53)
• Uranus (27)
• Neptune (13)
• Pluto (1)

Quiz
Now test your knowledge! Take out a sheet of
paper. Please answer these 3 questions in
complete sentences.
1. List all of the planets in order.
2. Why was Pluto taken out of the Solar
System?
3. Explain why some planets have more moons
than other planets.

Here’s a SOLAR-TASTIC movie and game
Movie
http://video.kids.nationalgeographic.com/video
/player/kids/science-space-kids/solar-system-
101-kids.html
Game
http://kids.nationalgeographic.com/kids/games/
actiongames/space-janitor/

Websites for kids
Planet Facts:
http://www.kidsastronomy.com/solar_system.htm
Puzzle Games:
http://solarsystem.nasa.gov/kids/puzzles.cfm
Journey of the Solar System:
http://www.kids-and-space.com/
Moon:
http://www.woodlands-junior.kent.sch.uk/time/moon/facts.htm

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