- Light year is measured in distance, not time.
- Scientists measure in light years, a huge unit, because space is huge and it's much easier to work with.
- Light's Speed= 300,000 kilometers/second
- Light Year: 1. Distance light travels in one years 2. One light year= 9.5 trillion kilometers or 5.9 trillion miles
- 10 M= 0.01 KM
- 0.002- caeden km/sec
- caeden year- 157,680
Galaxy Sort
- Groups of stars, gases, and dust held together by gravity
- Clusters: Galaxies that travel together
- 3 Main types: Spiral, Elliptical, and Irregular
- Spiral:
-Spiral shape is caused by the rotation of the galaxy
- Irregular:
-As their name indicates, they have irregular shapes
- Ellipticals:
-Appear elongated and spherical and basically massive blobs of stars
-Composed of mostly old stars