1. Organization of the universe

2. The Scale of the Universe

3. The universe is big, really, really big
There is 1 universe– it’s made of MANY galaxies--- which are made of tons of stars and gas.
Some (about 1%) of stars also have planets making solar systems.

4. Galaxies Contain:
Stars
Planets
Nebula gas
Black holes
Space

5. There are 3 types of galaxies:

6. Galactic Scale

7. Irregular Galaxies youngest galaxies contain a lot of nebula gas
Many new and young stars
No real shape

8. Irregular Galaxies

9. Spiral Galaxies
‘middle aged’ galaxies
star formation still happening
Old and young stars
Have nebula clouds
Have a bulge in the middle and a thin disk.
Have “arms”

10. Spiral Galaxies

11. Elliptical Galaxies older galaxies
very little gas or star formation anymore
Round or oval shape
Mainly old stars

12. Elliptical Galaxies

14. OUR GALAXY Is called the Milky Way Is a spiral galaxy
has a diameter of about 100,000 light-years.
And about 100 billion stars
OUR solar system lies about halfway out one of the arms (25,000 light-years from the center).