1. What is an Asteroid?

4. Asteroid Sizes

5. Where are they? Where do they come from?

7. 1 1 2 34

10. How do we study asteroid?

11. LINEAR NEO Search Systems

12. Asteroids: Years of Discovery 1

13. Hubble!

16. EROS Asteroid 433

19. Hayabusa Visiting Asteroid Itokawa

21. Why are we interested in Asteroids?

24. What happens if an Asteroid hits the Earth?

30. Earth Sterilizing Impact Mass Extinction Impact Civilization Threatening Impact

31. What Happens When an Impact Takes Place? Bolides (up to 5 MT) Great fireworks display, no damage Tunguska-class (15 MT) impact Damage similar to large nuclear bomb (city-killer) Average interval for whole Earth: 100 yr. Minor risk relative to other natural disasters (earthquakes, etc.) Larger local or regional catastrophes (e.g. 10,000 MT) Destroys area equivalent to small country Average interval for whole Earth: 100,000 yr. Moderate risk relative to other natural disasters Global catastrophe (> 1 million MT) Global environmental damage, threatening civilization Average interval for whole Earth: 1 million years Major risk relative to other natural disasters

32. Could it Happen?

35. Terrestrial Impact Frequency year century million yr. billion yr. ten thousand yr. 100 millionmillion10,00010010.01 Hiroshima Tunguska K/T TNT equivalent yield (MT) Global catastrophe Tsunami danger

36. What Can We Do?

37. Strategies Detect Project NEO (Near Earth Objects) http://neo.jpl.nasa.gov/ Deflect Gravitational Tractor Impactor Destroy

38. LINEAR NEO Search Systems

41. Questions??

42. Civilization Threatening Impact

43. Mass Extinction Impact

44. Earth Sterilizing Impact

45. Known Kilometer-Size Near Earth Asteroids 1000 500 199019952000 estimated total NEAs > 1 km Spaceguard official start

51. Looks like a potato?