unit10 - page171-10.13

Shall we grade 7, reference book, unit 10, planets, shall we magazine, exercise 13, read

the article and answer the questions.

The Solar System

The Solar System consists of our bright star, the Sun, the inner planets, Mercury, Venus,

Earth, Mars, and the outer planets, Jupiter, Saturn, Uranus, and Neptune.

Inner planets are composed of rock and metal.

Outer planets are composed of gas, and they are larger than the inner planets.

The Solar System also contains five dwarf planets.

They are Pluto, Eris, Hamea, Makimaki, and Ceres.

There are also millions of asteroids, comets, and meteorites in our Solar System.

Everything in the Solar System orbits around the Sun, that are more than 200 known moons

in our Solar System.

Of the eight planets, only Mercury and Venus have no moons.

The Earth has only one moon, it is the moon.

As far as we know, there is no proof of life on other planets.

Only our home planet, the Earth, has life on it.

It is the third closest planet to the Sun.

The name Earth is at least 1 ,000 years old.

It has a Germanic word, it means the ground.

People always want to learn more about the universe.

They try to explore space and discover new worlds.

NASA sent Voyager 1 and Voyager 2 into space in 1977.

Their mission was to provide images from spots beyond our Solar System.

They are now much farther away from the Earth and the Sun than Pluto is.

Both spacecraft are still sending scientific information about their surroundings.