“The Solar System” 23.1

Where are We?
•	Earth = one of 8 planets
•	Earth Revolves around the Sun
•	Sun + Planets = Solar System

Where did Earth Come From?...
Nebular Hypothesis.
“Nebula” = Cloud of dust & gas in Space
•	 Nebula spun really fast
•	 Flattened 
•	 Dust squishes together in middle
•	 Forms SUN
•	 Other Solids squish together and    
	 form planets
Now What?...
Poor Pluto…
Types of Planets
•	Terrestrial
–	Mercury, Venus, Earth, Mars
•	Jovian
–	Jupiter, Saturn, Uranus, Neptune
Escape Velocity
	Speed an object must travel to break free of a planet’s gravitational pull.