6. Rotation=Spinning

7. Revolution = Orbit

8. The Inner Planets

9. The Inner Planets Have no rings Only 0-2 moons each
Prograde rotation: looking down from the top of the planet, it moves counterclockwise, from left to right
Retrograde rotation: moves clockwise, from right to left

10. The Inner Planets Planets made of solid rock Have impact craters
Mercury
Surface of Mars

11. Mercury
Closest to the sun
Sun’s light obscures it from view

12. Mercury

13. Mercury Shortest Revolution: 88 days
Takes 59 days to spin once (rotate)
Has no moons

14. Mercury Very thin atmosphere Is heavily cratered
So close to sun
Very weak gravity
Is heavily cratered
Huge temperature range
427°C during day
-173°C at night

15. Venus Second planet 225-day orbit
Rotates slowly: 243 days to spin once
Retrograde
Has no moons

16. Venus
The earth’s twin
Almost same mass, size, and density

17. Venus Very hot Close to the sun
Very thick atmosphere, 96% Carbon Dioxide

18. Earth Third planet 365.24 days to make one revolution (orbit)
One rotation; 23 hours and 56 minute
Volcanically active
Has 1 moon

19. Earth
Life exists
Water present
Ideal temperature
Oxygen and CO2

20. Mars Fourth planet 687 days to orbit
One rotation: 24 hours, 37 minutes
Same tilt as Earth’s axis

21. Mars Volcanically active Has two moons
Largest volcano in solar system- Olympus Mons
Has two moons

22. Mars
Currently frozen water is at poles and liquid may be under the surface
No solid evidence of life on Mars

23. Asteroid Belt Rocks left over from the formation of the solar system
Located between Mars and Jupiter
50,000-1,000,000’s asteroids exist

25. The Outer Planets

26. The Jovian Planets Also known as the Gas Giants Large and Massive
Less dense than the inner planets
Atmospheres of mostly hydrogen and helium gas
Probably have a solid core

27. Jupiter Largest planet in the solar system
Twice the mass of all other planets combined
Extremely hot in the interior
If Jupiter had been larger, it could have become a star

28. Jupiter Revolution= 12 years
Fastest rotation in the solar system= 9 hrs, 50 min
Jupiter
Venus

29. Jupiter Has at least 17 moons and 4 rings
The Great Red Spot on Jupiter is a giant storm

30. Saturn
Fast rotation=10 hours, 30 minutes
Revolution= 29.5 years

31. Saturn At least 18 moons, several complex rings
Saturn is the least dense planet, less dense than water

32. Uranus Orbit period= 84 yrs Rotates once every 17 hours
Rotates like a rolling ball

33. Uranus At least 20 moons and 11 small rings
Greenish color indicates methane gas

34. Neptune Orbit period = 164 yrs Rotates every 16 hrs
Bluish color, named after the Roman god of the sea

35. Neptune Has eight moons and maybe four rings
The Great Dark Spot is a giant storm

36. Kuiper Belt
The Kuiper belt is a disk-shaped region past the orbit of Neptune containing many small icy bodies. It is now considered to be the source of the short-period comets.

37. Oort Cloud The outermost part of our solar system
The origin of most comets

38. Pluto
Smallest planet in the solar system
1 rotation= 6 days

39. Pluto 250 year revolution Pluto’s orbit is elliptical
Sometimes closer to the sun than Neptune

40. Pluto Pluto has one moon, half its size
Pluto is the largest object in the Kuiper Belt

41. Formation of the Solar System
Pluto may not be a planet at all, but just a large object in the Kuiper belt that surrounds our solar system

42. Formation of the Solar System
The Kuiper belt, discovered in 1992, is made of cold, icy planetesimals that never collided with each other to form a planet
Pluto is the largest object in the Kuiper Belt

43. Short Period Comet