1. Studying the Solar System Our goals for learning What does the solar system look like? What can we learn by comparing the planets to one another? What are the major features of the Sun and planets?

2. What does the solar system look like? 1. What is in it?

3. All large bodies in the solar system orbit in the same direction and in nearly the same plane

4. Eight major planets with nearly circular orbits Pluto (dwarf planet) is smaller than the major planets and has a more elliptical orbit

5. Swarms of Smaller Bodies Asteroids Kuiper Belt Objects Oort Cloud Comets (short period, long period)

6. History of Planet Count 8Re-classification of Pluto, Eris & Ceres as “Dwarf planets”, others to follow as debate continues 2006 9?Discovery of several large KBOs, especially Eris which is larger than Pluto. 2000-2005 9?Discovery of 1992 QB1 and other Kuiper Belt Objects1992-1999 9?Discovery of Charon1978 9Discovery of Pluto1930 8Re-classification of Ceres and other small bodies1851 13+Discovery of Neptune1846 12Discovery of Astrea1845 11Discovery of Ceres, Palls & Vesta1801-1807 7Discovery of Uranus1781 6Heliocentric System, (Copernicus)1550 7Geocentric universe: Sun, Moon & 5 planetsAntiquity Planet CountClassificaction/EventYear

7. What Counts as a Planet? The IAU definition of a planet (2006): is in orbit around the Sun, has sufficient mass so that it is nearly round has "cleared the neighborhood" around its orbit.

8. What can we learn by comparing the planets to one another?

9. At first glance the worlds of the solar system all appear to be unique

10. Comparative Planetology Comparing the planets reveals common patterns. Those patterns provide insights that help us understand Earth Stay focused on processes common to multiple worlds instead of individual facts specific to a particular world. We can learn more about a world like our Earth by studying in context with other worlds in the solar system.

11. What are the major features of the Solar System?

12. Density and Composition = Density = mass _ volume Measure a planet’s volume Measure a planet’s spin => calculate mass Result is a world’s bulk density. g/cm 3

13. Density and Composition Common materials Metals (mostly Iron) 7.9 g/cm 3 Rock (mostly Basalt) 3.3 g/cm 3 Carbon & hydrogen ices 0.4-1.5 g/cm 3 (volatiles)‏ H and He gases <<0.01 g/cm 3

14. Density and Composition Earth 5.5 g/cm 3 composition- iron, rock Saturn 0.7 g/cm 3 composition- some rock, volatiles and lots H&He Callisto 1.9 g/cm 3 Titan 2 g/cm 3 composition -rock and ice

15. Thought Question g/cm 3 Planet Mars has a bulk density of 3.9 g/cm 3 What materials is it made of ? A)Metal and Rock B)Rock and volatiles C)Rock and H&He D)Volatiles and H & He

16. What have we learned? What does the solar system look like? –Planets orbit Sun in the same direction and in nearly the same plane. What can we learn by comparing the planets to one another? –Comparative planetology looks for patterns among the planets. –Those patterns give us insight into the general processes that govern planets –Studying other worlds in this way tells us about our own Earth

17. What have we learned? How can we tell what planets are made of? –The bulk density of the planets reflect the type of materials the planets are composed of. –There are 4 main common types of material –Most planets are made of a mixture of these materials that are not necessarily represented on the surface.

18. Over 99.9% of solar system’s mass Made mostly of H/He gas (plasma)‏ Sun What are the major features of the Solar System?

19. Three Main Types of Large Bodies Terrestrial planets (rocky worlds)‏ Jovian planets (gas giant worlds)‏ Ice worlds (mostly moons and dwarf planets)

20. Terrestrials vs Jovians The terrestrial (or rocky) worlds are the 4 inner planets plus our Moon –They have a solid rock surface with an iron core and a weak to no atmosphere or magnetic field. There are 4 jovian (or gas giant) planets –These planets have NO solid surfaces – just gas and clouds that get denser as you move to their center. –They are mostly atmosphere around rocky cores and have a strong magnetic field

21. gas giant worlds are far from the Sun Rocky worlds are close to the Sun.

22. Jupiter – largest gas giant world Earth – largest rocky world gas giant worlds are much larger than rocky worlds

23. Rocky worlds have no rings and no, or few, moons. Gas Giant worlds have rings and many moons.

24. Ice Worlds Enough self-gravity to be spherical. Metal/rock core, ice mantle and crust. Some geological activity Two main locations: –Larger Icy moons orbiting gas giant planets –Largest objects in Kuiper belt in the outermost solar system (Pluto, Sedna, Quoaor and others)‏

25. Swarms of Smaller Bodies Many rocky asteroids and icy comets populate the solar system Solar system debris can be found everywhere, but close to the sun it is rocky and far from the sun, icy.

26. What have we learned? What are the major features of the Solar System –Motions of large bodies: All in same direction and plane –Two main planet types: Terrestrial and jovian –Minor type: ice worlds –Swarms of small bodies: Asteroids and comets

27. © 2014 Pearson Education, Inc. Which planets DO have rings? A.Saturn only B.Saturn and Uranus only C.Saturn, Uranus and Neptune only D.Saturn, Jupiter, Uranus and Neptune only E.All the planets have rings.

28. © 2014 Pearson Education, Inc. At what location(s) within the solar system would one find comets? A.the Oort cloud and the Kuiper belt B.the asteroid belt only C.the Kuiper belt and the asteroid belt D.the Kuiper belt only E.the Oort cloud only