1. What Makes Up the Solar System?
Lesson 5-2
What Makes Up the Solar System?

2. Solar System – made up of a star (the sun) and all planets and other objects that revolve around that star.
A. Includes 9 Planets
1. Planet – body that revolves around a star
2. Force of gravity between the star and planet holds the planet in orbit
3. Most planets have moons or satellites
a. Satellite – body that revolves around a planet
4. “My Very Excellent Mother Just Sent Us Nine Pizzas”

3. B. Inner Planets – all rocky and dense
1. Mercury:
a. closest to sun
b. size of Earth’s moon
c. no atmosphere – covered with craters and dust
2. Venus:
a. Brightest object in the night sky (after the moon)
b. same size as Earth

4. 3. Earth:
a. only planet known to support life
b. atmosphere keeps temperatures so that living things can survive
4. Mars:
a. red planet – reddish soil
b. atmosphere is mostly Carbon Dioxide

5. C. Outer Planets
1. Jupiter:
a. largest in solar system
b. has a ring & dozens of moons
c. can be seen w/out a telescope
2. Saturn:
a. has rings made of ice, dust, boulders and frozen gases
b. has dozens of moons

6. 3. Uranus:
a. has many moons and rings
b. rotates on an axis that is tilted more than other planets
4. Neptune:
a. several rings and moons
b. strongest winds in solar system
c. same size as Uranus
5. Pluto:
a. small and rocky
b. has an unusual orbit

7. D. Asteroids – chunks of rock too small to be called planets
1. found in the asteroid belt between Mars and Jupiter
E. Meteors – pieces of rock that travel through space
1. when one hits the Earth’s Atmosphere it burns
a. bright streak of light
b. “shooting star”
2. when one reaches Earth – called a meteorite

8. F. Comet – ball of ice, rock & frozen gases
F. Comet – ball of ice, rock & frozen gases that orbit the sun in irregular paths
1. Made of 3 parts
a. Nucleus – made of rock, gas and dust
b. Coma – circle made of water vapor and gas around the nucleus as it begins to melt
c. Tail – made of water vapor, dust and gas. As the comet gets closer to the Sun it gets longer. The solar wind pushes the tail away from the sun.