Earths and its neighbors

                                                                           Vocabulary#8
solar system: the sun and the objects that are traveling around it.

planet: any of the nine large bodies that travel around the sun and shiny by  reflecting its light.

gravity: a force of attraction,or pull,between any objectsand any other objects around it.

inertia: the tendency of a moving object to keep moving in a strigh line.

lithosphere:the hard,outer layer of earth,about 100 kilometers thick.

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

resource: any material that helps support life on Earth.

hydrosphere: Earth´s water.