Grade 6- Fourth Quarter

1. PLANETS IN SOLAR
SYSTEM

2. Introduction
• The solar system orbits the center of the Milky Way
Galaxy. It is composed of the Sun and the eight planets.
These are Mercury, Venus, Earth, Mars, Jupiter, Saturn,
Uranus, and Neptune. The eight planets of the solar
system can be described by their size, distance from
the sun, composition and other characteristics.

3. • The solar system is
composed of the Sun and
the eight planets, such as
Mercury, Venus, Earth, Mars,
Jupiter, Saturn, Uranus, and
Neptune. These planets are
classified as inner planets
and outer planets.

4. What are the inner planets?
• The first four planets, Mercury,
Venus, Earth and Mars are called
terrestrial or inner planets.
• They are solid and are mostly
made up of rocks and metal;
• they do not have rings. These are
the planets closer to the Sun.

5. MERCURY
• Mercury is the closest planet to the sun and also
the smallest planet in the solar system.
• The small and cratered planet does not have any
moons and zips around the sun faster than any
other planet in the solar system.
• The tiny planet is made up of a single continental
plate over a cooling iron core. As the core cools, it
solidifies, reducing the planet's volume and causing
it to shrink.

6. VENUS
• It’s the hottest planet in our solar system, even
though Mercury is closer to the Sun.
• It has a thick atmosphere full of the
greenhouse gas carbon dioxide and clouds
made of sulfuric acid.
• Venus looks like a very active planet. It has
mountains and volcanoes. Venus is similar in
size to Earth. Earth is just a little bit bigger.

7. EARTH
• Our home planet Earth is a rocky, terrestrial planet.
It has a solid and active surface with mountains,
valleys, canyons, plains and so much more.
• Our atmosphere is made mostly of nitrogen and
has plenty of oxygen for us to breathe. The
atmosphere also protects us from incoming
meteoroids
• A day on Earth lasts a little under 24 hours. One
year on Earth lasts 365.25 days. That 0.25 extra
means every four years we need to add one day to
our calendar. We call it a leap day (in a leap year)

8. MARS
• Mars is a cold desert world. It is half the size of Earth. Mars is
sometimes called the Red Planet. It's red because of rusty iron
in the ground.
• Like Earth, Mars has seasons, polar ice caps, volcanoes,
canyons, and weather. It has a very thin atmosphere made of
carbon dioxide, nitrogen, and argon.
• One day on Mars lasts 24.6 hours. It is just a little longer than a
day on Earth. One year on Mars is 687 Earth days. It is almost
twice as long as one year on Earth.
• Mars has two moons. Their names are Phobos and Deimos.

9. What are the outer planets?
• The last four planets Jupiter, Saturn, Uranus,
and Neptune are outer or Jovian planets. They
are called gas giants. These gas giants are so-
called because they are much larger than
other planets and are mostly made up of gas.
They are set-apart from the terrestrial planets
by the asteroid belt. All of these gas giants
have rings and moons.

10. WHAT IS AN ASTEROID BELT?
•The asteroid belt is a region
of space between the
orbits of Mars and Jupiter
where most of the
asteroids in our Solar
System are found orbiting
the Sun.

11. JUPITER
• Jupiter is the biggest planet in our solar system.
It's similar to a star, but it never got massive
enough to start burning. It is covered in swirling
cloud stripes.
• Jupiter is a gas giant and doesn't have a solid
surface, but it may have a solid inner core about the
size of Earth. Jupiter also has rings, but they're too
faint to see very well.
• One day on Jupiter goes by in just 10 hours. One
year on Jupiter is the same as 11.8 Earth years.
Jupiter has 80 confirmed moons.

12. SATURN
• Saturn isn’t the only planet to have rings, but it
definitely has the most beautiful ones. The rings
we see are made of groups of tiny ringlets that
surround Saturn.
• Saturn is a gas giant like Jupiter. It is made
mostly of hydrogen and helium. Saturn has a
thick atmosphere.
• Saturn has 63 moons! It also has 20 unconfirmed
moons we need to learn more about.

13. URANUS
• Uranus is made of water, methane, and ammonia fluids
above a small rocky center. Its atmosphere is made of
hydrogen and helium like Jupiter and Saturn, but it also has
methane.
• Uranus also has faint rings. The inner rings are narrow and
dark. The outer rings are brightly colored and easier to see.
• One day on Uranus lasts a little over 17 hours (17 hours and
14 minutes, to be exact). One year on Uranus is the same as
84 years on Earth. That’s a long time to wait for a birthday
cake.

14. NEPTUNE
• Neptune is dark, cold, and very windy. It's the last of the
planets in our solar system.
• It's made of a thick fog of water, ammonia, and
methane over an Earth-sized solid center. Its
atmosphere is made of hydrogen, helium, and methane.
• Neptune is encircled by six rings. One day on Neptune
goes by in 16 hours. Neptune has such a long journey
around the Sun it takes 165 Earth years to go around
once. That’s a long year!

16. What are the compositions of the planets?
• The terrestrial or inner planets have solid surfaces. These planets are
small and mostly made up of rock and metal. They have silicate mantle
surrounding a metallic core composed mostly of iron.
• The Jovian or outer planets are made up of hydrogen and helium and
they have small rocky core. Aside from being called gas giants, Uranus
and Neptune are also called ice giants. The ice giants have interior
composition of compounds like water, methane and ammonia.