1. The Solar System

2. The Sun The largest object in the solar system
The center of the solar system
The Sun’s gravity keeps all the other objects in orbit around the Sun.

3. Mercury Closest planet to the Sun A rocky planet No atmosphere
One side always faces the Sun – HOT
One side always faces away from the Sun – COLD
Sometimes can be seen from Earth

4. Venus Second brightest object in night sky Second closest to the Sun
Rocky planet
Thick, cloudy atmosphere
Closest planet to Earth

5. Earth Third planet Rocky planet Has liquid water Has oxygen gas
Probably the only planet with life

6. Mars Can be seen from Earth – appears reddish
Made of rocks with “rusty” iron
Has two moons
Has some water ice now – liquid water long ago

7. Jupiter Largest planet Called a “gas giant” because it is mostly gas
Liquid and solid layers are probably below the thick atmosphere
At least 18 moons
Seen from Earth

8. Saturn Second largest planet Gas giant
Rings are made of rocks, dust and ice
At least 18 moons
Visible from Earth

9. Uranus Seventh planet from the Sun A gas giant Has small rings
Not visible without a telescope
Discovered in 1781

10. Neptune Eighth planet from the Sun – usually A gas giant
Discovered in 1846

11. Pluto Smallest planet Rocky planet Very elliptical orbit
Sometimes is closer to Sun than Neptune
Its moon is almost as big as the planet
May be an “escaped” moon from a gas giant