1. Organization of the universe

2. The Scale of the Universe Visual 1

3. The universe is big, really big
There is 1 universe
– it’s made of MANY galaxies grouped into clusters

4. Each cluster is made of many galaxies
Galaxies contain tons of stars and gas.

5. Then SOME stars (about 1%) have planets making solar systems.

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

7. Galaxies There are 3 types of galaxies
That come in a wide variety of sizes and shapes

8. Galactic Scale

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

10. Irregular Galaxies

11. 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”

12. Spiral Galaxies

14. Elliptical Galaxies older galaxies
very little gas/dust or star formation anymore
Round or oval shape
Mainly old stars
Massive blob
Brighter
Have a bulge

15. Elliptical Galaxies

16. Images from the Hubble telescope

18. 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).