|solar system||The Sun (our star), Earth, our Moon, the other planets and other objects that are orbiting the sun.|
|Galaxy||a large group of stars, gas and dust held together by gravity. Our galaxy is called the Milky Way.|
|three types of galaxies||
a. spiral galaxy-has spiral arms, sort of like a pinwheel, the Milky Way is a spiral galaxy.
b. elliptical galaxy-shaped like an egg, believed to be older than spiral galaxies.
c. irregular galaxies-don't really have a shape.
|the Milky Way||
about 100,000 light years wide. light year is the distance that light travels in one year, about 9.5 TRILLION kilometers.
Our solar system is located in one of the spiral arms, we can't see the shape of the Milky Way because we are inside it.
|elliptical (egg shaped) galaxy|
|spiral galaxy (see where we are)|
|irregular galaxy (shapeless)|