1. Gravitational Force Every mass exerts a force on Every mass exerts a force on every other mass. every other mass.

2. Gravitational Force How does the mass of an object affect its gravitational force? How does the mass of an object affect its gravitational force? The bigger the mass, the more the gravitational force. The bigger the mass, the more the gravitational force. How does the distance between two objects affect the gravitational force between them? How does the distance between two objects affect the gravitational force between them? The bigger the distance, the smaller the gravitational force. The bigger the distance, the smaller the gravitational force.

3. Comets vs. Asteroids CometsAsteroids Made up of ice and dust Made up of rock Orbit through our solar system Always in our solar system In an eccentric orbit around the sun Usually orbit the sun in a belt between Mars and Jupiter Only visible when near the sun Not visible with the naked eye Meteor showers occur when the Earth passes through the comet’s orbit

4. Parts of a Comet Nucleus – solid dense main body made of ice and dust Coma – cloud of gas and dust caused by the heat of the sun. Tail – formed when the solar wind pushes the coma away from the sun

5. Famous Comets Halley’s Comet – Edmund Halley correctly predicted the comet’s orbital period to be 76 years. Halley’s Comet – Edmund Halley correctly predicted the comet’s orbital period to be 76 years. Shoemaker-Levy – first time scientists saw a comet impact a planet Shoemaker-Levy – first time scientists saw a comet impact a planet

6. Planet Impact Internet Activity Planet Impact Internet Activity Learn how the speed, size of the comet, size of the target, and angle of impact affect a comet’s path. Learn how the speed, size of the comet, size of the target, and angle of impact affect a comet’s path.