News etc Pluto demoted Now a dwarf planet

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

News continued… Charlotte Talks this morning (WFAE 90. 7 / 90. 3 ) wfae. org, on “Science and Religion, ” with Dr. Mike Corwin, UNCC n Posted in mp 3 on Web. CT n

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

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

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

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

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

Solar system Sun Sizes not to scale! Earth-Sun distance is the “astronomical Unit” (AU) n Planets at 0. 4, 0. 7, 1 (us!), 1. 5, 5, 10, 20, 40 Aus, and … n

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

Nearest Star 4. 2 light years (ly) away n c = 3 x 105 km/s n 1 ly ~ 9. 5 x 1012 km or about 63, 000 AU n So nearest star is 4. 2 times this or about 265, 000 AUs n

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

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

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

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

Observable Universe ~ 14. 7 Gly Hubble Deep Field