Transcript The Planets of our Solar System

Space
What is space?
• When you look at the night sky you can
see many beautiful stars. If you are out in
the country or camping in the mountains or
the desert away from the city lights, you
may see thousands of them. You may
even be able to see part of the Milky Way.
In a town or city, you can't see nearly as
many stars because the city lights create a
glow in the sky masking many of them.
Stars
• There are several different
kinds of stars in the sky.
Some are very big. A couple
of stars have been found that
are 100 to 200 times larger
than the sun. Some very old
stars are smaller than the
Earth. Scientists study stars
and place them in groups
based on how they are alike
and how they are different.
Our Solar System
• Our solar neighborhood is an
exciting place. The Solar
System is full of planets,
moons, asteroids, comets,
minor planets, and many other
exciting objects.
The Planets of our
Solar System
The Inner Planets
plus Pluto
Our Solar System
Our Star:
the Sun and its planets
Our Sun with some other stars
Some other stars
Mercury
• Smallest
terrestrial planet
• Closest to the
sun
• Virtually no
atmosphere
Venus
• Similar to Earth in
size and mass
• 7.5 months in its
year
• 8 months for one
day
• Rotates from east
to west (most go
from west to east)
Earth
• Only planet in our solar
system with oxygen and liquid
water.
• Home to millions of species.
• It is the largest of the four
rocky planets.
• It has an atmosphere that is
78% nitrogen and 21%
oxygen, with trace amounts of
water vapor, carbon dioxide
and other gaseous molecules.
Mars
• The Red Planet
• Its atmosphere is
95% carbon dioxide
• Possibly had water
at one time
• Mars is titled on its
axis and has
seasons
Jupiter
• Largest and most
massive planet in
our solar system
• Thick atmosphere
made up of
hydrogen and
helium
• Dozens of moons
Saturn
• Second largest
planet
• Rings made of
chunks of ice and
rock
• Titan, a moon of
Saturn, was
discovered in 1665
Uranus
• Has rings similar to
Saturn’s
• It rotates from top
to bottom instead of
sideways like Earth
does
• 25 or more moons
Neptune
• A cold blue planet
• Visible clouds
• Believed to be
slowly shrinking
because of internal
heating
• At least 13 moons
Pluto
• Dwarf planet
• Pluto is usually farther from the
Sun than any of the eight
planets; however, due to the
eccentricity of its orbit, it is
closer than Neptune for 20
years out of its 249 year orbit.
Pluto crossed Neptune's orbit
January 21, 1979, made its
closest approach September 5,
1989, and remained within the
orbit of Neptune until February
11, 1999. This will not occur
again until September 2226