1. Welcome Astronomers! Today: Creating 2 scale models of the solar system D.E.A.R. Review for this week’s test DQ: A standard basketball in the NBA has a diameter of 25 cm. If this basketball represents the Earth, what would be the diameter of a ball that represents Mars?

2. Review of Football Field Solar System Does this image show an accurate scale model?

3. 1. What do you notice about the positions of the planets relative to the sun? The farther you travel from the sun the farther apart each planet is from the next. Review of Football Field Solar System 2. What do you notice about the sizes of the planets relative to their positions? The inner planets (Mercury, Venus, Earth, Mars) are all much smaller than the outer planets. The outer planets are larger but vary more in size.

4. 3. The 4 inner planets are called rocky planets. Why? Compact solid planets with rocky surfaces 4. The outer planets are called gas giants. Why? Large planets that contain more than 10 times the mass of Earth Their compositions are mostly gases, such as hydrogen, and small amounts of rocky material (mostly at their cores). Review of Football Field Solar System

5. New Scale Model: State of Oregon as the Solar System If the state of Oregon is 640 km and we had to fit a model of the solar system inside of it, what would be the distance from the sun and diameter of each planet? PlanetDistance from the sun (km) Model distance (km) Actual diameter (km) Model Diameter (km) Sun-----------------------------1,400,000 Mercury58 million Venus108 million Earth150 million Mars228 million Jupiter779 million Saturn1434 million Uranus2872 million Neptune4495 million Pluto5870 million640 km If 640 km on the map = 5870 million km in space, what is the scale of this model?

6. Works Cited Be sure to include print and electronic sources and put them in alphabetical order.