1. Solar System Formation and MOTION

2. Process of Solar System Formation

3. Solar Nebula
The solar nebula is the name of the nebula that formed into our own solar system

4. Nebula
Gas and dust, very cold

5. Two forces at work
Gravity and pressure balance each other out to prevent nebula from collapsing or falling apart

6. Birth of a Star
The central part of the solar nebula contained so much mass and had become so hot that hydrogen fusion began.
Outward pressure in the center balanced with the inward force of gravity that the gas stopped collapsing
Our sun was born!

7. Planets
Gas giants (Jupiter, Saturn, Uranus, and Neptune) collected large amounts of dust in the cooler, outer solar nebula
Closer to the sun, it was too hot for gases to remain, so these inner planets are made of rocky material (Mercury, Venus, Earth, Mars)

8. Everything in the solar system moves according to strict physical laws
Planetary Motion
Everything in the solar system moves according to strict physical laws
Each object follows different time frames and patterns for this to occur

9. Rotation
Rotation-Earth's spinning on its axis, which happens every 24 hours or a day.
This is how day and night happen

10. Revolution
Orbit – a planet rotates on its own axis and revolves around the sun in a path
Revolution- Earth completes an orbit around the sun which happens every days or a year (leap years would be 366 days)
This is how the seasons occur

12. How were planetary orbits discovered?
Johannes Kepler, German astronomer discovered this in 1601
Kepler's First Law of Motion
Planets do not move in a circle around the sun, but in an elongated circle, or ellipse

13. Distances in space
Astronomical unit (AU) – represents the average distance between the Earth and the sun
1AU =149,597,817 km=92,955,807 mi

14. Kepler's Second Law
Kepler discovered that planets move faster when they are closer to the sun and slower when they are further away

15. Kepler's Third Law
If you know a planet's period of revolution, you can calculate its distance from the sun.

16. Law of universal gravitation
Developed by Newton, states that the force of gravity depends on the product of the masses of the objects divided by the square of the distance between them.
Gravity is always working in the universe and it depends on the objects size, mass and location