Vocabulary 8

 Solar system: The sun and the objects that are traveling around it.

Planet: Any of the eight large bodies that travel aruond the sun and shine by reflecting its light.

Gravity: A force of attraction, or pull, between any object and any another objects around it.

Inertia:The tendency of moving object to keep moving in straight line.

Lithosphere:The hard, outer layer of earth,about 100 kilometers thick.

crust:The rocky surface that makes up the top of lithosphere.

Resource:Any material that helps support life on erath.

 Hydrosphere:Earth's water.