1. Characteristics of Inner and Outer Planets Pages 725-739

2. Characteristics of the Inner Planets
They are 4 planets closest to the sun: Mercury, Venus, Earth and Mars. Located inside Asteroid Belt
Their insides, surfaces, and atmospheres formed in similar ways and follow similar patterns
Very similar to each other, they are small and have rocky surfaces. They are dense. Do NOT have rings
Often called “terrestrial planets” because they resemble Earth, “terra-” means “Earth”
All have rocky crusts and dense mantles and cores

3. Processes and Surface Features
Tectonics
Processes of change in a crust due to the motion of hot material underneath
Volcanism
When molten rock moves from a planet’s hot interior onto its surface
Weathering & Erosion
When weather or small impacts break down rocks and the broken material is moved
Impact Cratering
When a small object hits a planet’s surface so fast that it causes an explosion

4. Mercury Size- about 38% of Earth’s diameter it is 4878 km
Distance from sun- about 39% of Earth’s distance it is 58,000,000 km
Surface- thin, hard rocky surface covered with many plains and craters
Atmosphere- very thin, some sodium and other gases
Ability to support life- none, there is NOT any sign of life on Mercury, lack of water and oxygen along with hot temperatures make life unlikely
Moons- none
Rotation- 59 Earth days
Revolution- .24 Earth years
Daytime(sunlit side) temperature 430ºC Nighttime(shaded side) temperature -190ºC

5. Venus
Size- slightly smaller than Earth 95% of Earth’s diameter, it is 12,104 km
Distance from sun- 108,000,000 km from sun
Surface- covered with rock similar to some parts of Earth, has volcanoes with lava flows and strange domes
Atmosphere- Very thick and cloudy, mostly carbon dioxide, clouds partly sulfuric acid
Atmospheric pressure is 90 times heavier than Earth’s and would crush a human
Has clouds of sulfuric acid
Ability to support life- Life does NOT appear to exist on Venus, lack of water along with harsh temperatures and atmosphere make life on Venus unlikely

6. Venus (cont’d)
Sometimes called “Earth’s twin” or “Earth’s sister planet” due to similarity
Retrograde rotation- rotates “backward” from east to west (opposite of Earth)
Rotates very slowly, one rotation takes about 8 Earth months and one revolution around sun takes about 7.5 Earth months (One day is longer than one year)
Moons- None

7. Earth Size- 12,756 km diameter Distance from Sun- 150,000,000 km
Surface- Crust is a solid rocky surface, 70% is covered by water
Atmosphere- up to 100 km thick, made up of 78% Nitrogen, 21% Oxygen, 1% other gases
Ability to Support Life- Life does exist on Earth. Gaseous oxygen, liquid water and moderate temperatures are hospitable for life on Earth
Rotation takes 24 hours
Revolution takes days
Earth has one moon

8. Mars Size- 53% of Earth’s diameter, it is 6794 km
Distance from Sun-228,000,000 km from sun
Surface-Rocky surface with carbonite rocks high in iron, creating red color Polar ice caps contain frozen water and carbon dioxide
Atmosphere- Very thin, with thin clouds Mostly carbon dioxide, only 1% of Earth’s atmospheric pressure
Ability to support life- It is possible that primitive bacteria may have lived on Mars or may now live there but none has been found. Existence of liquid water makes life on Mars a possibility

9. Mars continued
Has polar ice caps of frozen water and frozen carbon dioxide
Rotation Earth days
Revolution- 1.9 Earth years
Mars has largest volcano in solar system, called Olympus Mons
Moons- 2 Phobos and Deimos

10. Characteristics of The Outer Planets
These are the planets outside of the Asteroid Belt, they are: Jupiter, Saturn, Uranus, Neptune and the dwarf planets Pluto and Eris
Jupiter, Saturn, Uranus, and Neptune are called “Gas Giants” . They are much larger than Earth and do not have solid surfaces
Pluto and Eris are small and rocky, like the terrestrial planets.
The gas giants do not have well-defined surfaces but have deep atmospheres that are typically about 75% hydrogen, 24% helium, and 1% other elements
Gas giants likely have solid cores of rock, ice, frozen carbon dioxide and other compounds

11. Jupiter Size- It is 142,800 km Distance from Sun- 778,000,000 km
Surface and atmosphere of gas and liquid it does not have a well-defined surface
Ability to support life- Lacks water, oxygen and moderate temperatures needed to support life. NO known life
Largest planet in solar system with 300 times the mass of Earth
Rotation- .41 Earth days (fastest)
Revolution- 29 Earth years
Moons- numerous, 16 that are 10 km or larger and many smaller ones
Has dark rings
Great Red Spot is storm on Jupiter, twice as big as Earth

12. Saturn Size- 120,540 km Distance from sun 1,427,000,000 km
Surface and atmosphere of a gas giant, it does not have a well-defined surface but has syrup-like mixture of helium and hydrogen and a thick atmosphere of gaseous helium and hydrogen
Ability to support life- Lacks water, oxygen, and moderate temperatures needed to support life
Rotation Earth days
Revolution- 29 Earth years
Moons- many, 25 that are 10 km or larger plus smaller ones
Low density planet, could float in water
Prominent rings- mostly chunks of ice and rocks

13. Uranus Size- 51,200 km Distance from Sun- 2,871,000,000 km
Surface-consists of blue-green clouds made up of tiny ice crystals of methane, and rock. The crystals of methane have frozen out of the planet's atmosphere.
Uranus' atmosphere is about 83% hydrogen, 15% helium and 2% methane.
Ability to support life- Lacks water, oxygen, and moderate temperatures needed to support life, NO known life
Rotation Earth days, is retrograde rotation like Venus, and rotates on side
Revolution- 84 Earth years
Moons- 27
Rings- 11 dark rings

14. Neptune Size- It is 49,500 km Distance from Sun- 4,497,000,000 km
Neptune's surface is probably similar to Uranus': various "ices" and Silicates (rock) with about 15% hydrogen, some water, and a little helium
Atmosphere is mostly hydrogen and helium with a small amount of methane.
Ability to support life- Lacks significant water, oxygen, and moderate temperatures needed to support life. NO known life.
Rotation Earth days
Revolution- 165 Earth years
Visible clouds in atmosphere
Moons- 11 (NASA)
3 Very dark rings, 1 very faint ring

15. Pluto Size- about 17% of diameter of Earth. It is 2200 km
Distance from sun- It is 5,913,000,000 kilometers
Rocky, icy surface is very small
Thin atmosphere of methane gas
Ceres- new dwarf planet, it was classified as the largest asteroid in the Asteroid Belt (it is between Mars & Jupiter).
Pluto- was classified as a planet, now classified as a dwarf planet
Eris- new dwarf planet, past Pluto it is an icy body near the edge of our solar system.