1. PLANET FACTS

2. MERCURY Length of Day = 58.65 Earth Days
Length of Year = Earth Days
Mean Surface Temp = degrees F
Surface: Dusty layer of minerals, surface is plains, cliffs, and craters
Atmosphere = trace amts of H and He

3. MERCURY 2/5ths the size of Earth (second smallest in the Solar System)
Diameter: miles
Mean distance from sun = 35 million miles
Moons: 0
Rings: 0

4. VENUS Length of Day = 243 Earth Days Length of Year = 225 Earth Days
Mean Surface Temp = degrees F
Surface = rocky, dusty, waterless expanse of mountains, canyons, and plains, with a 200-mile dried-up river bed.
Atmosphere = 95% carbon dioxide, N, sulfuric acid, traces

5. VENUS About 650 miles smaller in diameter than Earth
Diameter: 7519 miles
Mean distance to sun: million miles
Moon: 0
Rings: 0

6. EARTH Length of Day = 1 Earth Day Length of Year = 1 Earth Year
Mean Surface Temp = degrees F
Surface: Earth is made up of water (70%), air, and solid ground. It appears to be the only planet with water.
Atmosphere: N, O, and others

7. EARTH
Four planets in our solar system are larger and four are smaller than Earth
Diameter: 7926 miles
Mean distance from sun: 92.9 million miles
Moons: 1
Rings: 0

8. MARS Length of Day: 24 Earth hrs, 37 minutes, 23 seconds
Length of Year: 687 Earth days
Mean Surface Temp = degrees F
Surface: Canyons, dunes, volcanoes, and polar caps of water ice and carbon dioxide ice
Atmosphere: 95% carbon dioxide

9. MARS About 1/2 the size of Earth Diameter: 4194 miles
Mean distance from sun: million miles
Moons: 2
Rings: 0

10. JUPITER Length of Day: 9 Earth hours, 55 minutes
Length of Year: 12 Earth years
Mean Surface Temp = degrees F
Surface: A hot ball of gas and liquid
Atmosphere: Whirling clouds of colored dust, H, He, methane, water, and ammonia. The Great Red Spot is an intense windstorm larger than Earth.

11. JUPITER
11 times the diameter of Earth - largest planet in Solar System
Diameter: miles
Mean distance from sun: million miles
Moons: 16
Rings: 1

12. SATURN Length of Day: 10 Earth hrs, 40 minutes, 24 seconds
Length of Year: 29.5 Earth years
Mean Surface Temp = -288 degrees F
Surface: Liquid and gas
Atmosphere: H and He

13. SATURN About 10 times larger than Earth Diameter: 74978 miles
Mean distance from sun: million miles
Moons: 19
Rings: ~ 1000??

14. URANUS Length of Day: 17 Earth hours Length of Year: 84 Earth years
Mean Surface Temp = degrees F
Surface: Little is known
Atmosphere: H, He, and methane

15. URANUS 4 times larger than Earth Diameter: 32193 miles
Mean distance from sun: million miles
Moons: 17
Rings: 11

16. NEPTUNE Length of Day: 16 Earth hours, 7 minutes
Length of Year: 165 Earth years
Mean Surface Temp = degrees F
Surface: Liquid layer covered with thick clouds; constant raging storms
Atmosphere: H, He, methane, and ammonia

17. NEPTUNE About 4 times the size of Earth Diameter: 30775 miles
Mean distance from sun: 2680 million miles
Moons: 8
Rings: 4

18. PLUTO Length of Day: 6 Earth days, 9 hours, and 18 minutes
Length of Year: 248 Earth years
Mean Surface Temp = degrees F
Surface: A giant snowball of methane and water mixed with rock
Atmosphere: Methane

19. PLUTO Less than 1/5 the size of Earth Diameter: 1423 miles
Mean distance from sun: million miles
Moons: 1
Rings: 2

20. ASTEROID BELT
Several hundred thousand asteroids have been discovered and given provisional designations so far. Thousands more are discovered each year. There are undoubtedly hundreds of thousands more that are too small to be seen from the Earth. There are 26 known asteroids larger than 200 km in diameter. Our census of the largest ones is now fairly complete: we probably know 99% of the asteroids larger than 100 km in diameter. Of those in the 10 to 100 km range we have cataloged about half. But we know very few of the smaller ones; there are probably considerably more than a million asteroids in the 1 km range.
Main Belt: located between Mars and Jupiter roughly AU from the Sun; further divided into subgroups: Hungarias, Floras, Phocaea, Koronis, Eos, Themis, Cybeles and Hildas (which are named after the main asteroid in the group).