The Milky Way

These are examples of other galaxies: Where do we fit in?

Andromeda

Cartwheel

We look into the galaxy from Earth

A picture of our galaxy from within our galaxy

The Milky Way visualized using infrared

The Milky Way is Spiral

The Galaxy SongWhat to Listen For

• How fast does earth revolve?• How fast do stars move?• Where in the Milky Way is Earth?• How many stars in the Milky Way• How many ly across?• How thick in the middle of the galaxy?• How thick out by us?• How far are we from center of the Milky Way?• How often do we go around?

http://www.gecdsb.on.ca/d&g/astro/music/Galaxy_Song.html

The Galaxy Song• Whenever life gets you down, Mrs.

Brown,And things seem hard or tough,And people are stupid, obnoxious or daft,And you feel that you've had quite eno-o-o-o-o-ough...

• Just remember that you're standing on a planet that's evolvingAnd revolving at nine hundred miles an hour,That's orbiting at nineteen miles a second, so it's reckoned,A sun that is the source of all our power.The sun and you and me and all the stars that we can seeAre moving at a million miles a dayIn an outer spiral arm, at forty thousand miles an hour,Of the galaxy we call the "Milky Way".

• Our galaxy itself contains a hundred billion stars.It's a hundred thousand light years side to side.It bulges in the middle, sixteen thousand light years thick,But out by us, it's just three thousand light years wide.We're thirty thousand light years from galactic central point.We go 'round every two hundred million years,And our galaxy is only one of millions of billionsIn this amazing and expanding universe.

• (Animated calliope interlude) • The universe itself keeps on expanding and

expandingIn all of the directions it can whizzAs fast as it can go, at the speed of light, you know,Twelve million miles a minute, and that's the fastest speed there is.So remember, when you're feeling very small and insecure,How amazingly unlikely is your birth,And pray that there's intelligent life somewhere up in space,'Cause there's bugger all down here on Earth.

The Essay

• To answer the Galaxy essay on the test you will need to – Describe/define what a galaxy is – Describe the 3 types (pictures would be

helpful)– Describe the Milky Way (a picture would be

helpful)• Size, shape, # of stars etc. . .• Where are we? What stars do we see etc. . .

So we have talked about 3 of the 4 essays

1. Analyzing light

2. Life cycle of a star (choose one or the other)

3. Galaxy• The only one we did not talk about was the

characteristics of stars, these were 1 full day of notes and 28.2 in the book.

– Temperature, distance, color, size, elements, magnitude etc. . .

– FOR EACH CHARACTERISTIC Talk about what the characteristic is, why it is important in describing a star and how it is determined