The Solar System

1. The Solar System Chapter 29 Review

2. Main Concepts and Big Ideas • The Heliocentric Model and Geocentric Model were ways 3 Dead Greek Guys thought the planets move in the Solar System • Terrestrial and Jovian Planets are the two major types of planets in the Solar System

3. Mars Earth SUN Geocentric Model • Definition: • All planets and Sun revolve around the Earth - Earth is at center of Solar System • Author: Aristotle • Problem: Geocentric Model does not explain Retrograde Motion

4. Epicycle Mars Earth SUN Next Dead Guy: Ptolemy • Aristotle’s Geocentric Model could not explain why a planet could have both a forward and reverse motion in the sky – Retrograde Motion • Ptolemy explained Retrograde Motion through Epicycles

5. Epicycles & Retrograde Motion Orbital Path Mars Retrograde Motion

6. Heliocentric Model • Definition: • All Planets revolve around Sun • Author: • Copernicus • Confirmation of Heliocentric Model by Galileo through observations made with newly invented telescope

7. The Terrestrial Planets • The terrestrial planets are the four innermost planets in the solar system, Mercury, Venus, Earth and Mars. • They are called terrestrial because they have a compact, rocky surface like the Earth's. • The planets, Venus, Earth, and Mars have significant atmospheres while Mercury has almost none.

8. The Inner Planets • Mercury • Large number of craters suggest little change since formation • Thin Atmosphere • Closeness to Sun • Small Size • Venus • Very slow rotation on axis – every 243 days • Orbital period of 224 • High Volcanic Activity • Very Hot!! • Close to sun & insulating atmosphere

9. The Inner Planets • Mars & Earth • Common Events • Volcanism • Presence of Water • Atmosphere • Earth • Escape of insulating Carbon Dioxide keeps Earth from getting too hot

10. The Jovian Planets • Jupiter, Saturn, Uranus, and Neptune are known as the Jovian (Jupiter-like) planets, because they are all gigantic compared with Earth, and they have a gaseous nature like Jupiter's. • The Jovian planets are also referred to as the gas giants, although some or all of them might have small solid cores.

11. The Outer Planets • Jupiter • 92% of Jupiter is Hydrogen & Helium – similar composition to Sun • Saturn • Least dense in Solar System • Period: 29.5 Years • Ring System • Uranus • Horizontal Axis – only planet that rotates this way

13. Asteroids, Comets, and Meteoroids • Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets. • Asteroids are material left over from the formation of the solar system. One theory suggests that they are the remains of a planet that was destroyed in a massive collision long ago.

14. Asteroids • Asteroids – or Minor Planets – are fragments of rock that orbit the Sun • Most asteroids exist in a region between the orbits of Mars and Jupiter – The Asteroid Belt • Classified based on composition • Asteroids are remains of planetesimals – affected by Jupiter • Two types of asteroids NOT in Asteroid Belt between Mars and Jupiter – Trojan Asteroids & Earth Grazers

15. Comets • Made of dust and ice • Originate in Oort Clouds • Orbit Sun in large elliptical orbits • Coma and tail – SOLAR WIND

16. Meteoroids, Meteors and Meteorites • Meteoroids are small bits of rock or metal flying through space • Visible fireballs come from meteors burning up in atmosphere • Any part that hits the Earth is called a meteorite

17. Review Questions • Directions: At the bottom of your sheet of notes, answer the following questions: • Between the orbits of what planets is the asteroid belt located? • In what direction does the tail of the comet go? • How is a meteoroid different from a meteorite? • In what way are the orbits of Trojan asteroids and Earth Grazers unlike orbits of other asteroids?