1. Charles Hakes Fort Lewis College1 Photos

2. Charles Hakes Fort Lewis College2 Chapter 4, 5 Debris - Asteroids and Comets

3. Charles Hakes Fort Lewis College3 Tutor (Shane) l Thursday 5-6 (or longer if needed) BH640

4. Charles Hakes Fort Lewis College4 Movie comments l Martian atmosphere l Asteroid density

5. Charles Hakes Fort Lewis College5 Debris Asteroids Mostly between Mars and Jupiter. Silicate (rocky) predominate inner region Carbonaceous more common as you move out Meteoroids - Little Asteroids Micrometeoroids - Really little ones (dust) Often follow comet paths Comets - Dirty Snowballs

6. Charles Hakes Fort Lewis College6 Chapter 4 Asteroid Eros

7. Charles Hakes Fort Lewis College7 Asteroids (Minor Planets) Most are in the “Asteroid belt” between Mars (1.5 AU) and Jupiter (5.2 AU). Largest is Ceres (940 km in diameter). Orbits generally more elliptical than planets Trojan asteroids - in stable orbits 60° ahead of and behind Jupiter. Vesta - http://apod.nasa.gov/apod/ap110919.html http://apod.nasa.gov/apod/ap110919.html

8. Charles Hakes Fort Lewis College8 Figure 4.4 Inner Solar System

9. Charles Hakes Fort Lewis College9 Figure 4.6 Asteroid Images

10. Charles Hakes Fort Lewis College10 Figure 4.7 Asteroid Eros

11. Charles Hakes Fort Lewis College11 Asteroid Density How close are the Asteroids to each other?

12. Charles Hakes Fort Lewis College12 Asteroid Density How close are the Asteroids to each other? Number of known asteroids ~100,000. Distance from sun 2-4 A.U.

13. Charles Hakes Fort Lewis College13 Asteroid Density How close are the Asteroids to each other? Number of known asteroids ~100,000. Distance from sun 2-4 A.U. Area ~  (4AU) 2 -  (2AU) 2 = 8.5x10 17 km 2 Say there are really lots more… (~1,000,000,000) Then each one still gets 8.5x10 8 km 2

14. Charles Hakes Fort Lewis College14 Asteroid Density How close are the Asteroids to each other? Number of known asteroids ~100,000. Distance from sun 2-4 A.U. Area ~  (4AU) 2 -  (2AU) 2 = 8.5x10 17 km 2 Say there are really lots more… (~1,000,000,000) Then each one still gets 8.5x10 8 km 2 Distance = 3x10 4 km (~2.5x diameter of Earth)

15. Charles Hakes Fort Lewis College15 Asteroids (Minor Planets) Over 2000 Earth-crossing asteroids are known. Near Earth - http://apod.nasa.gov/apod/ap111001.html http://apod.nasa.gov/apod/ap111001.html

16. Charles Hakes Fort Lewis College16 Discovery 4-1a What Killed the Dinosaurs?

17. Charles Hakes Fort Lewis College17 Figure 4.15 Barringer Crater (near Winslow, AZ ~25,000 years ago)

18. Charles Hakes Fort Lewis College18 Figure 4.17 Tunguska Debris (Siberia, 1908)

19. Charles Hakes Fort Lewis College19 Figure 4.16 Manicouagan Reservoir (~200,000,000 years ago)

20. Charles Hakes Fort Lewis College20 Discovery 4-1b What Killed the Dinosaurs?

21. Charles Hakes Fort Lewis College21 Figure 4.18 Meteorite Samples a) stony silicate b) iron

22. Charles Hakes Fort Lewis College22

23. Charles Hakes Fort Lewis College23 This is: A) A natural rock outcropping B) New FLC Landscaping C) Something else

24. Charles Hakes Fort Lewis College24 Comets Dirty snowballs

25. Charles Hakes Fort Lewis College25 Comets Nucleus Dirty Snowballs - “dirt” accumulates on surface Often only a few km in diameter Coma Bright part around the nucleus Could be 100,000 km in diameter Tail Could be up to 1 A.U. in length! Ion Tail - points directly away from the Sun Dust Tail - points away from Sun, but “drags” a bit. Hydrogen Envelope - surrounds all, but not visible

26. Charles Hakes Fort Lewis College26 Figure 4.8 Halley ’ s Comet

27. Charles Hakes Fort Lewis College27 Figure 4.9 Comet Tails a) Giacobini-Zinner b) Hale-Bopp (1997)

28. Charles Hakes Fort Lewis College28 Figure 4.10 Comet Trajectory

29. Charles Hakes Fort Lewis College29 Figure 4.11 Halley ’ s Comet Closeup from Giotto spacecraft

30. Charles Hakes Fort Lewis College30 Figure 4.12 Comet Reservoirs Oort Cloud huge spherical reservoir of long period comets Kuiper Belt outside the orbit of Neptune in plane of solar system reservoir of short period comets e.g. Haley’s comet

31. Charles Hakes Fort Lewis College31 Figure 4.14 Meteor Showers

32. Charles Hakes Fort Lewis College32 Figure 4.13 Meteor Trails

33. Charles Hakes Fort Lewis College33 Figure 4.13 Meteor Trails

34. Charles Hakes Fort Lewis College34 Three Minute Paper Write 1-3 sentences. What was the most important thing you learned today? What questions do you still have about today’s topics?