1. The Birth of a Solar System: Governing Laws

2. Newton’s Law of Universal Gravitation  Force – A push or a pull  Gravity – force of attraction between two objects  It pulls to the center of an object with mass  Larger masses have a larger gravitational force.  The closer the object, the more the force of gravity.  Equation:

3. Newton’s Law of Universal Gravitation  Gravity depends on:  Distance of 2 objects  The size of the arrows represent the magnitude of gravitational attraction.  Draw this:

4. Newton’s Law of Universal Gravitation  Gravity depends on:  Mass of 2 objects  Draw this:

5. Newton’s Law of Universal Gravitation Draw this: Distance = r Draw this: Mass = m Force = F G is a gravitational constant number that never changes.

6. Newton’s Law of Universal Gravitation

8. Newton’s 1 st Law of Motion: Inertia  Inertia – the tendency of an object at rest to stay at rest or to keep moving in the same direction at the same speed, until acted upon by an outside force  In other words: An object in motion, stays in motion. An object at rest, stays at rest.

9. Newton’s 1 st Law of Motion: Inertia

13. Orbits of the planets  Orbit – a regular, repeating path that one object in space takes around another one.  An object in an orbit is called a satellite.  Satellites can be natural (planets, moons) or man-made (space station)  Orbits are Elliptical shapes (oval)  Planets are almost circular  Asteroids are eccentric or squashed ovals

14. Orbits of the planets  Orbit – a balance between gravity and inertia  Draw this:

15. Orbits of the planets Without gravity, an Earth-orbiting satellite would go off into space along a straight line. With gravity, it is pulled back toward Earth. A constant tug-of-war takes place between the satellite's tendency to move in a straight line, or momentum, and the tug of gravity pulling the satellite back.

16. Orbits of the planets For the next 2 minutes try to list all of our planets in order on your notes. The next slide will show you these planets and their orbital planes. Orbital plane - the flat, disk-shaped space that connects the center of the object being orbited with the center of the orbiting objects

17. Orbits of the planets Orbits within our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, (Pluto)

18. Orbits of the planets  Notice the comet’s plane

19. Orbits of the planets Almost all these bodies also travel in the same orbital plane, a thin disk surrounding the sun and extending to the edge of the solar system. The orbital plane usually prevents planets or other celestial bodies from bumping into each other. Some comets orbit outside the orbital plane, perpendicular or at an angle to the rest of the solar system bodies.

20. Orbits of the planets Orbital Velocity Law - Mass = m Distance = r Velocity (speed) = v Velocity is distance divided by time

21. Solar Systems For the next 2 minutes try to make a list of all of the things that are in a solar system. Try to explain how a solar system formed?

22. Solar System For the next 2 minutes try to make a list of all of the things that are in a solar system.