The Essential Question
What make a
planet…a planet?
 Who named the
planets?
 How do we
determine the
status of a planet?
 What ever
happened to Pluto?
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(Google Images, 2010.)
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(Google Images, 2010.)
Mercury
Venus
Earth
Mars
Jupiter
Neptune
Uranus
Pluto (sometimes!!)
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The Romans matched
planetary attributes with
particular deities and
named the known planets
accordingly.
First astronomers focused
their attention on the sun,
the moon, and visible
planets Mercury, Venus,
Mars, Jupiter, and Saturn.
They believed each of
these celestial bodies
influenced a particular day
of the week.
(Google Images, 2010)
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Mercury was named
after the messenger to
the gods,
Venus, the brightest
planet visible to the
unaided eye, was named
for the goddess of love
and beauty.
Jupiter, more than twice
as massive as all the
other planets combined,
earned the name of the
superior god.
(Google Images, 2010.)
A planet, to be defined as
a planet, must:
1.
2.
3.
4.
Be massive enough to
form itself into a
stable, almost
spherical shape;
Orbit a star;
Have cleared its orbit
of other bodies;
Not have its orbit
unduly interfered with
by other planets
(Google Images, 2010)
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Pluto, is the secondlargest known dwarf
planet.
Tenth-largest body
observed directly
orbiting the Sun.
Originally classified as a
planet.
Pluto is now considered
the largest member of a
distinct population
called the Kuiper belt.
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Planets are huge round stars.
They must maintain an orbit.
They were named after Roman gods.
Pluto is no longer a planet.
Pluto is a large star.
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If you could, which planet would you
visit? Why?
Please visit:
 National Aeronautics and Space
Administration-- www.nasa.gov
 Astronomy for Kids -www.kidsastronomy.com
 Kidsites.com -http://www.kidsites.com/sitesedu/science.htm
 The Nine Planets Solar System Tour -http://nineplanets.org/