1. The Outer Planets

2. The Outer Planets to Scale
Jupiter Saturn Uranus Neptune Pluto

3. Outer Planet Similarities
All are tens of thousands of miles across
Much larger than the inner planets
All are made of gas - hydrogen and helium
No rocky surface like the inner planets
All are not very dense (b/c made of gas)
Why do the outer planets share these similarities?
Why don’t the outer planets have more in common with the inner planets?

4. Jupiter Largest planet in solar system (11 time larger than Earth)
Colorful cloud bands
Rotation = 10 hours
-250°F
60 moons orbit it

5. Great Red Spot Hurricane-like storm, fueled by heat inside of Jupiter
Large enough to cover 3 Earths
Discovered by Galileo nearly 400 years ago
Largest known storm in solar system

6. Saturn Least dense planet - Would float on water!
Revolves around sun once every 29 yrs.
One day = 11 hours
Has at least 31 moons largest is Titan

7. Saturn’s Rings Made of countless small chunks of ice and rock
170,000 miles wide, <1 mile thick
Edge of ring system points towards Earth
Cassini (1997) put probe on Titan in 2004

8. Uranus Discovered by accident (1781) Blue-green color
350°F at cloud tops
1977 discovered it has a faint, dark ring system
1986 Voyager 2 spacecraft studied rings and moons
At least 11 rings and 22 moons

9. Uranus’ Axis Axis tilted 98° from its orbit
One orbit of sun = 84 Earth years
Uranus rotates on its axis once every 17 hours

10. What’s Wrong with Uranus?
Following its discovery, astronomers calculated its orbit
Uranus mysteriously speeded up, then slowed down

11. Neptune Discovered at its predicted position (1846)
1 rev = 164 Earth years
Blue color -370°F at cloud tops
4 rings- 2 thin, 2 thick
Great Dark Spot in 1989, but not 1994
Rotates once on its axis every 16 hours
Wispy, white streaks are clouds

12. Pluto Coldest, outermost planet Has not been visited by a spacecraft
Smallest planet
Only outer planet without ring system and thick atmosphere
One moon- Charon
6 billion kilometers from sun
One rev = 248 Earth days
Rotates once every 6 days

13. The S.S. Family Portait

14. Other objects in
The solar system

15. Asteroids * Rocky object, smaller than a planet, that orbits a star
Most are smaller than a kilometer in diameter
few are 1,000 kilometers across
Few come close to Earth and are captured by
Earth’s gravity
If one is big enough and does not completely burn up,
it could possibly hit Earth.

16. Region between Mars and Jupiter where most asteroids
Asteroid Belt
Region between Mars and Jupiter where most asteroids
orbit the sun

17. Meteor Brief streak of light seen when an asteroid enters the
earth’s atmosphere and burns up
“ shooting stars”
“ falling stars”
“meteor shower”

18. Meteorite Asteroid that hits the surface of a planet or moon after
traveling through space

19. Comet
* Ball of ice, rock, frozen gases and dust that orbits the sun