2. The Solar System Chapter 19 By Dawneen Corbett

3. Different Views of the Solar System n Earth-Centered model: included the Earth, moon, sun, five planets, and the sphere of stars. n Sun-Centered model: the moon revolved around the Earth, the planets revolved around the Sun. n Modern view: 9 planets that orbit the sun along with many other small objects.

4. The Modern View of the Solar System The Modern View of the Solar System

5. Forming The Solar System n Formed 4.6 billion years ago n Formation occurred from clouds of gas, ice, and dust n Beginnings of the sun: nuclear fusion began in a cloud that reached temperatures 10 million ‘C n Nuclear Fusion: atoms with low mass combine to make heavier elements.

6. Regions of the Solar System n The inner solar system includes Mercury, Venus, Earth, Mars which are small, rocky planets with iron cores. n The outer planets include Jupiter, Saturn, Uranus, Neptune, and Pluto. These planets are made of hydrogen, helium, methane, and ammonia.

7. Planet Motion n Orbits are elliptical not circular n The Sun is “offset” in the ellipse n Inner planets travel faster than outer planets.

8. Scientists of the Solar System n Many Greek Scientists: Earth- Centered Model n Nicholas Copernicus: Polish astronomer, Sun-Centered Model n Johannes Kepler: German, Mathematician, made the discovery that the orbits are elliptical. Find out that planets travel at different speeds.

9. Comprehension Questions 1.When did the solar system begin to form? 2.What model of the solar system did Copernicus propose in 1543? 3.What do the sun, nine planets, their moons, and many smaller objects make up? 4.Which planets are small and rocky and have iron cores? 5.Which planets, except for Pluto, are composed mostly of lighter elements?

10. Answers to Comprehension Questions 1. About 4.6 billion years ago 2. sun-centered 3. solar system 4. inner planets 5. outer planets

11. Works Cited n http://www.cde.ca.gov/standards/ n Content Standards for California Schools http://www.cde.ca.gov/standards/ http://www.cde.ca.gov/standards/ n n Our Solar System.jpg www.manitobamuseum.mb.ca/ pl_night_sky.html n http://www.findsounds.com/ISAPI/search.dll http://www.findsounds.com/ISAPI/search.dll n http://new.wavelist.com/ n http://159.115.210.94/~bloomfie/lbweb/DMA2 00/found_poems/eriko_nishio/sound/wind.wav http://159.115.210.94/~bloomfie/lbweb/DMA2 00/found_poems/eriko_nishio/sound/wind.wav http://159.115.210.94/~bloomfie/lbweb/DMA2 00/found_poems/eriko_nishio/sound/wind.wav n Science Voyages: Earth and Life Sciences By Glencoe