News, etc.News, etc.

Pluto Pluto demoted! demoted! (Now a “dwarf (Now a “dwarf planet”)planet”)

New rule: New rule: shaped by shaped by gravity and …gravity and …

Dominates its Dominates its neighborhoodneighborhood

News continued…News continued…

Charlotte Talks Charlotte Talks this morning this morning (WFAE 90.7 / 90.3 (WFAE 90.7 / 90.3 ) wfae.org, on ) wfae.org, on “Science and “Science and Religion,” with Dr. Religion,” with Dr. Mike Corwin, Mike Corwin, UNCCUNCC

Posted in mp3 on Posted in mp3 on WebCTWebCT

Lab tonight and SundayLab tonight and Sunday

TONIGHT: “Meet and Greet” sessionTONIGHT: “Meet and Greet” session May receive lab manual binderMay receive lab manual binder SUNDAY: Need lab manual! SUNDAY: Need lab manual!

(Bookstore)—will do lab #1 on (Bookstore)—will do lab #1 on constellations! Read Introduction in constellations! Read Introduction in advance! (Quiz possible.)advance! (Quiz possible.)

Topics Survey ResultTopics Survey Result

10. What makes a planet? 10. What makes a planet? 9. Navigation by stars9. Navigation by stars8. Paranormal8. Paranormal7. Comets, meteors and 7. Comets, meteors and

asteroids, oh my!asteroids, oh my!6. Space travel physics6. Space travel physics5. Extraterrestrial life5. Extraterrestrial life4. Stars!4. Stars!3. Paranormal3. Paranormal2. Black Holes2. Black Holes1. Constellations1. Constellations

Astrology resultsAstrology results

52 filled out and 52 filled out and turned in (with one turned in (with one choice)choice)

3 picked their 3 picked their “correct” sign “correct” sign descriptordescriptor

What would we What would we expect?expect?

Is it Is it significant significant ?? One year: 3 sigmas!?!One year: 3 sigmas!?!

Scale of the Scale of the Universe Universe

How big and far away is How big and far away is stuff?stuff?

Earth-MoonEarth-Moon

Earth ~8k miles Earth ~8k miles in diameterin diameter

Rotates?Rotates? Moon about a ¼ Moon about a ¼

of the Earth sizeof the Earth size Moon is ~100 of Moon is ~100 of

its diameters its diameters awayaway

Solar systemSolar system

Earth-Sun Earth-Sun distance is the distance is the “astronomical “astronomical Unit” (AU) Unit” (AU)

Planets at 0.4, 0.7, Planets at 0.4, 0.7, 1 (us!), 1.5, 5, 10, 1 (us!), 1.5, 5, 10, 20, 40 Aus, and …20, 40 Aus, and …

Sizes not to scale!

Sun

New (now, dwarf) planet – New (now, dwarf) planet – 7/31/057/31/05

96 AUs96 AUs Really a Really a

Kuiper Belt Kuiper Belt object?object?

Orbit Orbit inclined 45 inclined 45 degreesdegrees

““Xena”?Xena”?

Nearest StarNearest Star

4.2 light years (ly) 4.2 light years (ly) awayaway

c = 3 x 10c = 3 x 1055 km/s km/s 1 ly ~ 9.5 x 101 ly ~ 9.5 x 101212

km or about km or about 63,000 AU63,000 AU

So nearest star is So nearest star is 4.2 times this or 4.2 times this or about 265,000 AUsabout 265,000 AUs

Our Milky Way GalaxyOur Milky Way Galaxy

MWG about MWG about 100,000 ly in 100,000 ly in diameterdiameter

We are ~ 2/3 the We are ~ 2/3 the way outway out

Nearest Galaxy, in Nearest Galaxy, in AndromedaAndromeda

2 million light 2 million light years awayyears away

(about 20 (about 20 MWG MWG diameters)diameters)

The “Local Group”The “Local Group”

A few dozen A few dozen galaxiesgalaxies

Spread over a Spread over a few Mlyfew Mly

Nearest Large GroupNearest Large Group

Virgo Virgo Cluster ~60 Cluster ~60 Mly away Mly away (20 LG (20 LG dia’s)dia’s)

~ 1000 ~ 1000 member member galaxies in galaxies in itit

ObservableObservable Universe ~ Universe ~ 14.7 Gly14.7 Gly

Hubble Deep FieldHubble Deep Field