1. GRAVITY

2. What is Gravity?
Well, this scientist named Newton discovered this force when he was sitting under a tree and an apple fell on his head…
Law of Gravity: What goes up MUST come down
Gravity- a force that attracts objects towards one another
Surface Gravity- The gravitational attraction between a planet and the objects on its surface.

3. So what causes gravity?
The amount of gravity something has is related to its mass.
Mass- how much of something there is.
**An object’s mass never changes, no matter where it is. For example, your mass on Earth and your mass on Jupiter is the same. It is your WEIGHT that changes.
Weight- How heavy something is.
**Your weight changes depending upon how much gravity is pushing down on you. For example, although your mass would stay the same, your weight would be many times what it is on Earth if you were on Jupiter.

4. How does gravity effect the Solar System?
The Sun’s gravity always pulls the planets towards the center of the system.
The planet’s gravity always keep their moons in orbit around them.
All planets (and objects in space) have a natural need to move in a straight line, but because of gravity, it pulls that line around into a circle…or ORBIT!