1. News, etc. Pluto demoted! (Now a “dwarf planet”) Pluto demoted! (Now a “dwarf planet”) New rule: shaped by gravity and … New rule: shaped by gravity and … Dominates its neighborhood Dominates its neighborhood

2. News continued… Charlotte Talks this morning (WFAE 90.7 / 90.3 ) wfae.org, on “Science and Religion,” with Dr. Mike Corwin, UNCC Charlotte Talks this morning (WFAE 90.7 / 90.3 ) wfae.org, on “Science and Religion,” with Dr. Mike Corwin, UNCC Posted in mp3 on WebCT Posted in mp3 on WebCT

3. Lab tonight and Sunday TONIGHT: “Meet and Greet” session TONIGHT: “Meet and Greet” session May receive lab manual binder May receive lab manual binder SUNDAY: Need lab manual! (Bookstore)—will do lab #1 on constellations! Read Introduction in advance! (Quiz possible.) SUNDAY: Need lab manual! (Bookstore)—will do lab #1 on constellations! Read Introduction in advance! (Quiz possible.)

4. Topics Survey Result 10. What makes a planet? 9. Navigation by stars 8. Paranormal 7. Comets, meteors and asteroids, oh my! 6. Space travel physics 5. Extraterrestrial life 4. Stars! 3. Paranormal 2. Black Holes 1. Constellations

5. Astrology results 52 filled out and turned in (with one choice) 52 filled out and turned in (with one choice) 3 picked their “correct” sign descriptor 3 picked their “correct” sign descriptor What would we expect? What would we expect? Is it significant ? Is it significant ? One year: 3 sigmas!?! One year: 3 sigmas!?!

6. Scale of the Universe How big and far away is stuff?

7. Earth-Moon Earth ~8k miles in diameter Earth ~8k miles in diameter Rotates? Rotates? Moon about a ¼ of the Earth size Moon about a ¼ of the Earth size Moon is ~100 of its diameters away Moon is ~100 of its diameters away

8. Solar system Earth-Sun distance is the “astronomical Unit” (AU) Earth-Sun distance is the “astronomical Unit” (AU) Planets at 0.4, 0.7, 1 (us!), 1.5, 5, 10, 20, 40 Aus, and … Planets at 0.4, 0.7, 1 (us!), 1.5, 5, 10, 20, 40 Aus, and … Sizes not to scale! Sun

9. New (now, dwarf) planet – 7/31/05 96 AUs 96 AUs Really a Kuiper Belt object? Really a Kuiper Belt object? Orbit inclined 45 degrees Orbit inclined 45 degrees “Xena”? “Xena”?

10. Nearest Star 4.2 light years (ly) away 4.2 light years (ly) away c = 3 x 10 5 km/s c = 3 x 10 5 km/s 1 ly ~ 9.5 x 10 12 km or about 63,000 AU 1 ly ~ 9.5 x 10 12 km or about 63,000 AU So nearest star is 4.2 times this or about 265,000 AUs So nearest star is 4.2 times this or about 265,000 AUs

11. Our Milky Way Galaxy MWG about 100,000 ly in diameter MWG about 100,000 ly in diameter We are ~ 2/3 the way out We are ~ 2/3 the way out

12. Nearest Galaxy, in Andromeda 2 million light years away 2 million light years away (about 20 MWG diameters) (about 20 MWG diameters)

13. The “Local Group” A few dozen galaxies A few dozen galaxies Spread over a few Mly Spread over a few Mly

14. Nearest Large Group Virgo Cluster ~60 Mly away (20 LG dia’s) Virgo Cluster ~60 Mly away (20 LG dia’s) ~ 1000 member galaxies in it ~ 1000 member galaxies in it

15. Observable Universe ~ 14.7 Gly Hubble Deep Field