1. The Origin of Stars, Planets, and Life in the Universe Dr. Natalie Batalha nbatalha@science.sjsu.edu

2. How many planets are there in our Solar System? Poll Question:

3. Taking an Inventory of the Solar System Pluto Neptune Comet Uranus Mars Earth Saturn Mercury Sun Venus Jupiter

4. http://www.cfa.harvard.edu/iau/lists/InnerPlot.html

6. Solar System Table of Contents: I. Sun II. Mercury, Venus, Earth, Mars III. Asteroid Belt IV.Jupiter, Saturn, Uranus, Neptune V. Kuiper Belt (icy asteroids) VI.Oort Cloud (comets)

7. SIZESHAPEORBITTEMPCOMP Which of the following criteria are important for defining a planet?

8. Size and Shape: Earth is spherical, asteroid Gaspra is not. 12,800 kilometers (avout 8000 miles) 15 kilometers (about 9 miles)

9. Asteroid Ceres is spherical and about the size of Texas. Is it a planet?

10. Io Europa Ganymede Callisto Moon Mercury Mars Pluto

11. Definition so far: a) Orbits the Sun; b) Is at least as large as Pluto. CeresGanymede YESNO YESNO

12. Orbital Characteristics Mercury Earth Mars 7°7° Venus Saturn Jupiter Uranus Neptune Pluto 17°

14. Poll Question: Why is Pluto’s orbit different from those of the other 8 planets?

15. Discovery of Kuiper Belt Objects 1992, Jane Luu and David Jewitt More than 1,000 KBO’s now known 11 Pluto-sized KBO’s Pluto is a Kuiper Belt Object

16. How to Find Kuiper Belt Objects

18. The Orbits of Some Kuiper Belt Objects

19. Artist’s Depiction of UB313 Credit: Robert Hurt (IPAC)

20. UB313 (1500 miles)

21. Should UB313 be the 10 th Planet in the Solar System? Yes No

22. SizeOrbitHistoryPopulation Which of the following criteria are important for defining a planet?

23. 193 planets orbiting other stars (a total of 155 systems) have been identified to date. What do they tell us?

24. Most are in elliptical orbits

25. Gas giants are seen orbiting very close to their parent star! CopyrightCopyright © 1998-2006 Lynette R. Cook

26. Three planets all within 0.2 AU (Mercury orbits at 0.4 AU!)

27. Giant planets with 10x’s the mass of Jupiter. CopyrightCopyright © 1998-2006 Lynette R. Cook, All Rights Reserved

28. The International Astronomical Union is working to craft a definition that satisfies both Solar System and Extra-Solar System findings.

29. Summary Object size and orbit main criteria Historical context a consideration (Pluto is already on all of the plastic placemats!) Membership in a larger population will also be a consideration Object must be smaller than about 13 x’s Jupiter’s mass

30. For more information: Discovery of UB 313: http://www.gps.caltech.edu/~mbrown/ First Discovery of Kuiper Belt Objects: http://www.ifa.hawaii.edu/faculty/jewitt/kb.html List of planets orbiting other stars: http://exoplanet.eu