Targets 1. Explain the possible Origin of Earth using the Protoplanet Theory. 2. Describe each of these space objects; nebula, solar system, universe, protoplanet. 3. Distinguish the independent variable from the dependent variable on a graph. 4. Looking at the slope of a graph, identify the pattern of the data. 5. Using part to whole math, calculate the size of an circle that is representative of the Earth.