1. SOLAR SYSTEMS CHAPTER 21

2. definition Objects that revolve around a star Major members – Planets – Moons Minor members – Dwarf planets – Asteroids – Comets – meteoroids

3. What is a planet? (as of Aug. 2006) The IAU said that the definition for a planet is now officially known as "a celestial body that ( a) is in orbit around a star (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a (nearly round) shape and has cleared the neighborhood around its orbit." (not in a swarm of rocks) (c) has cleared the neighborhood around its orbit." (not in a swarm of rocks)

4. Our solar system scoreboard Planets= 8 Moons= 167 Dwarf planets= 5 Asteroids= 536,000+ Comets= 3,062

5. Exosolarsystems Other solar systems 661 new solar systems confirmed! Over 3000 planets (exoplanets) First discovered in 1995 Estimated over 50 BILLION

6. Earth like planets (habitable zone) Maybe 2? Gliese D – 6x more massive than earth “superearth” – In Libra – 20 lya HD 85512 b – In Vela – 26 lya

7. HOW DO ASTRONOMERS FIND NEW PLANETS???????

8. Radial Velocity Planets are detected by studying light shifts due to star wobbles Uses Doppler Effect – Red light moves AWAY – Blue light moves TOWARDS

9. Astrometry Measures star wobbles from geometry

10. Transit method Planet blocks star (eclipse) Light from star is lessen Kepler mission

11. Optical detection Block star’s light out using a chronograph

12. List of exoplanets http://exoplanet.eu/catalog/

13. Exoplanet missions Kepler- launched 2009 Has found 77 planets so far

15. METHODS to find a new planet http://planetquest.jpl.nasa.gov/Planet_Finder /planetfinder.html http://planetquest.jpl.nasa.gov/Planet_Finder /planetfinder.html

16. Other research LBT (large binocular telescope) Keck telescopes (Hawaii) Spitzer Space Telescope – Infrared telescope

17. OUR SOLAR SYSTEM

18. Our solar system

20. The planets drawn to scale

21. INNER PLANETS

22. Terrestrial Rocky No rings Smaller compared to Outer planets

23. MERCURY No atmosphere Temperatures fluctuate wildly MESSANGER is currently orbiting Mercury- has completed 282 orbits (so far!)

24. Sept. 29, 2009 MESSANGER

25. Messenger 9/21/11 Mapping surface of Mercury

26. MESSANGER IMAGE Aug. 23. 2012

27. VENUS THICK atmosphere THICK atmosphere – Hot! – Crushing pressure Rotation is retrograde Rotation is retrograde – Sun rise in west; set in east

28. Pancake volcanoes

30. MARS Thin atm. Windy Surface similar to Earth – Volcanoes – Old river valleys- where’s the water? – Best chance to find fossil (life?) in SS

32. Opportunity and Spirit http://marsrovers.jpl.nasa.gov/home/

33. CURIOSITY landed Aug. 6, 2012

34. CURIOSITY CONFIRMS WATER ONCE FLOWED!!

35. Mars Moons Phobos Deimos

37. Jovian Planets Outer planets Large Many moons all have rings Made of gas

38. JUPITER Often captures comets/asteroids – Shoemaker/Levy comet (1994)

39. Jupiter’s Ring system Feb. 2007

40. Jupiter’s New Moons Jupiter now has 63 known moons 23 moons were discovered in 2002-3 by Earth-based telescopes http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=Moons

41. Saturn’s Rings Made of Water ice and dust Sheppard moons keep rings in place

43. Uranian Weirdness

44. A few of Uranus’s moons MIRANDA PUCK ARIEL OBERON

45. Neptune Very active weather

46. Liquid nitrogen volcanoes Liquid nitrogen volcanoes Cantaloupe terrain Cantaloupe terrain Underground oceans? Underground oceans? Alien life? Alien life? Triton-

48. Planet ? 2003 UB313 Renamed Eris (Xena)

49. What is a planet? (as of Aug. 2006) The IAU said that the definition for a planet is now officially known as "a celestial body that ( a) is in orbit around a star (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a (nearly round) shape and has cleared the neighborhood around its orbit." (not in a swarm of rocks) (c) has cleared the neighborhood around its orbit." (not in a swarm of rocks)

50. Pluto Dwarf planet

52. Lowell Observatory where Pluto was discovered 1939

54. Plutoids Dwarf planets beyond Neptune Established in 2008

55. Planets, dwarf planets, plutoids

56. How many moons does Pluto have?

57. We’re on the way… New Horizons spacecraft was launched in Jan. 2006 Will arrive at Pluto July 2015