In our solar system, nine planets circle around our Sun . The Sun sits in the

middle while the planets travel in circular paths (called orbits) around it .These nine planets travel in the same direction (counter- clockwise looking down from the Sun's north pole ). The picture on the right shows the different paths and positions of each planet (not

to scale).

The solar system is made up of two parts: •  The inner solar system contains Mercury,

Venus, Earth and Mars . These four planets

are closest to the Sun  .   

• The outer solar system contains Jupiter,

Saturn, Uranus, Neptune and Pluto  .   The

inner planets are separated from the outer planets by the Asteroid Belt

COMPOSITION

• ROCKY PLANETS (Mercury - Venus - Earth - Mars - Pluto)

The rocky planets are mostly made up of rock and metal . These planets are very heavy and move slowly . They also do not have rings and very few moons.

• GAS PLANETS (Jupiter - Saturn - Uranus - Neptune)

The gas planets are mostly made up of gases (hydrogen and helium ). These planets are light for their sizes (just like a big air balloon ) and move quickly . They have rings and lots of moons

SIZE

• SMALL PLANETS (Mercury - Venus - Earth - Mars - Pluto)

The small planets have diameters less than 13000 km across . Mercury and Pluto are

sometimes referred to as lesser planets because they are so tiny.

• GIANT PLANETS (Jupiter - Saturn - Uranus - Neptune)

The giant planets have diameters greater than 48000 km . The giant planets are sometimes

also referred to as gas giants .

Our solar system is centered around the Sun • The Sun is a star - it is not a planet . Our

Sun is just like the stars we see in the night sky . The Sun is also the only star we see during the daytime .

• The Sun's center is about 15 million degrees Celsius

. The Sun is so hot that planets millions of kilometers away can feel its heat... T

hat's *mighty hot*!

Planets

• Mercury is the planet closest to our Sun, and it is the eighth largest of

the nine planets.

Mercury

Venus

• Venus is the second planet from the Sun, and the sixth largest of all the nine planets.

• Venus' hot temperature is due to what we call "the Greenhouse Effect ." The large amount of carbon dioxide in Venus' atmosphere acts like a blanket .The heat gets trapped underneath the thick layer of clouds . Because the heat has nowhere to go, Venus gets hotter and stays hot .

Venus

Earth

• Earth is the third planet from the Sun, and the fifth largest of the

nine planets .

Earth

Mars

• Mars is the fourth planet from the Sun, and the seventh largest of the

nine planets.

Mars

Jupiter

• Jupiter is the fifth planet from the Sun and by far the largest of all nine planets . Jupiter is more than twice as massive as all the other planets combined - It's 318 times bigger than the Earth !

• Jupiter does not have a solid surface due to its gaseous composition . The swirls and bands we see when looking at Jupiter are the tops of clouds high in its atmosphere .

Saturn

• Saturn is the sixth planet from the Sun, and the second largest of the nine planets .

• Saturn is a giant gas planet which is made up of about 75% hydrogen and 25% helium . It's most famous for its thousands of beautiful rings .

• Saturn's rings are made up mostly of water ice, but they may also include rocky particles with icy coatings .

• Saturn is made up of materials which are lighter than water . If placed in a big pond, Saturn would float much like an ice cube does in a glass of water .

Uranus

• Uranus is the seventh planet from the Sun and the third largest of the nine

planets (in size ). Uranus is larger in size but smaller in weight than Neptune .

• Uranus is a giant gas planet which is

made up of mostly rock and various ices .

Neptune

• Neptune is the eighth planet from the Sun and the fourth largest (by

size ) of the nine planets . Neptune is smaller in size but it's heavier than Uranus .

• Neptune's blue color is the result of a gas called "methane " in its atmosphere

Asteroids

• Asteroids are chunks of rock and metal that orbit around the Sun . Scientists think that they are loose material that never formed into planets .

• The Main Asteroid Belt is located betwe en Mars and Jupiter

• The total mass of all the asteroids is les s than that of the Moon.

Dwarf Planet

Created by: Master

Nopphadol Panyadee

• http://kids.nineplanets.org/