1. Solar System Notes
Solar System - An area that normally has one star with planets, moons, asteroids and comets orbiting the star. Our solar system has 8 planets, dwarf planets, hundreds of moons, countless asteroids and comets

2. Solar System Formation
1. Was a giant Nebula (cloud of gas and dust)
2. Nearby explosion caused it to start spinning
3. Most of the stuff pulled to center (the sun)
4. Remaining stuff continued spinning around sun – planets, comet, asteroids

3. The Order of the Planets
1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune
1. My
2. Very
3. Educated
4. Mother
5. Just
6. Served
7. Us
8. Nachos

4. Compare the size of the Sun to all 8 Planets!

5. Compare the sizes of the Terrestrial Planets:

6. Mercury: Closest to the Sun Shortest Revolution
Terrestrial Planet –Rocky Surface
Inner Planet
No Moons
1 day = 58 Earth days
1 year = 88 Earth days – shortest year

8. Venus: Close in size, mass and density to Earth “Earth’s Twin”
Hottest Average Temp.
No Moon
Retrograde Rotation – Spins backwards
Inner planet
Terrestrial Planet
1 day = 243 days – longest day – longer than year
1 year = 224 days

10. Earth: 1 moon (Luna) Has liquid water Has the only known life
Inner planet
Terrestrial planet
Revolution = days
Rotation = 24 hours
Prograde Rotation

12. Mars: 2 Moons Thin Atmosphere The “Red Planet” Smaller than Earth
Terrestrial planet (inner planet)
1 day = 24.5 hours
1 year = 687 days

14. Compare the sizes of the Gas Giants

15. Jupiter Largest Planet Made mostly of H and He Many moons (about 66)
Has a red spot (1.5 X the diameter of Earth)
Gas Giant – No Solid Surface
Has a few rings.
1 day = 10 hours – shortest day
1 year = 12 Earth years

17. Saturn: Made mostly of H and He Many moons (about 62)
Less dense than water would float in a tub.
Largest rings
Gas Giant – no Solid surface
1 day = 10.5 hours
1 year = 29.5 years

19. Uranus: Much smaller than Jupiter and Saturn
Tilted at a 90 degree angle
Has many moons (27)
Retrograde rotation – spins backwards
Gas Giant – No Solid Surface
Has Rings
1 day = 18 hours
1 year = 84 years

21. Neptune: Much smaller than Jupiter and Saturn Many moons (13)
Gas Giant – No Solid Surface
Has a few rings
1 day = 19 hours
1 year = years – longest year

23. Pluto (No longer a “planet”)
Dwarf Planet
1 moon which is more than half the size of Pluto (they orbit around each other).
Orbit is so elliptical that it’s path is inside Neptune’s for 20 years
It just became last again in 2005.
A dwarf planet is a celestial body that:
1. Orbits the sun.
2. Has enough mass to assume a nearly round shape.
3. Has not cleared the neighborhood around its orbit.
4. Is not a moon.
The main distinction between a dwarf planet and a planet is that planets have cleared their path around the sun while dwarf planets tend to orbit in elliptical paths that cross each other.

24. Ceres is in Asteroid Belt between Mars and Jupiter
Ceres is in Asteroid Belt between Mars and Jupiter. “Plutoids” are Dwarf Planets that orbit out beyond Pluto.

25. Smaller Objects
Asteroids - Rocky, metallic objects that orbit the sun, normally in an orbit similar to a planet
Comet – Made of ice and rock. It’s orbit takes it close to the sun and then very far. As it gets close, comet starts to melt creating a tail

26. Not to Scale
Comet’s Path
Asteroid Belt

27. Smaller Objects
Meteor - A piece of rock from space that enters Earth’s atmosphere and burns, creating a bright streak of light across the sky. (shooting star)
Meteoroid – A small, broken up pieces of asteroids or comets.
Meteorite – A piece of rock that lands on the Earth.