SCIE 1920U Chapter Notes - Chapter 1: Kuiper Belt, Ballpoint Pen, Virgo Supercluster
Document Summary
A solar system consists of a star, planets, moon, as well as asteroids and icy comets. Galaxy is a great island of stars in space that may contain millions, billions. Billions of galaxies are scattered across the universe. Milky way is of the two largest among more than 70 galaxies that make up the local group. Groups of galaxies with more than a few dozen large members are often called galaxy clusters. Observations show that galaxies and galaxy clusters appear to be arranged in giant chains and sheets with huge voids between them; they are called superclusters. We are located at the outskirts of the local supercluster. One au is about 150 million kilometers. One light year (ly) is the distance that light travels in one year, which is 10 trillion kilometers, or 300,000 km/s. Au is used within our solar system, while ly is used for distance galaxies and starts.
