1. Formation of Our Solar System

2. Nebulas
Interstellar cloud containing gases such as hydrogen and helium and dust particles like carbon and iron.
Irregular shape

3. Solar Nebulas Gravity pulls matter together.
Very small gravitational attraction.
Pressure pushes particles apart.
Low temperatures-slow movement

4. Solar Nebulas Form Two or more Nebulas collide
Nearby star explodes adding matter
Gravity overcomes pressure
Nebula collapses inward
Solar system is formed

5. Planetesimals Nebula collapse Temperature and gravity increase
Nebula begins to rotate
Rotating nebula flattens into a disk
Debris stick together forming small solid regions measuring one km across

6. Planets Larger planetesimals gain more material due to larger gravity
Terrestrial and gas planets form
Low temperatures allow gas giants to grow
Warmer temperatures close to the sun allow inner planets to be solid

7. Birth of a Star Center of a Nebula contains the most mass.
Hydrogen fusion begins.
Gasses stopped collapsing
10 million years to form our Solar System

8. Planetary Motion
Rotation-spinning motion on the axis giving us night and day
Revolution-one complete lap around the sun
Period of Revolution is called a year

9. Kepler’s First Law of Motion
Planets moved around the sun in an elliptical orbit. • •
focus
Semimajor axis
Major axis

10. Kepler’s Second Law of Motion
Planets move faster when closer to the sun.
Velocity has to increase due to an increase of gravitational attraction

11. Kepler’s Third Law of Motion
Compares a planets period of revolution to it’s semimajor axis.
Can determine a planets distance from the sun.
Formula-P2=a3 ; P=period of revolution
a=semimajor axis

12. Newton and Gravity
All objects have mass therefore gravitational attraction.
The Moon is falling around the Earth.