01:750:109 Chapter Notes - Chapter 1: Usable Fuel, Milky Way, Virgo Supercluster
Document Summary
Our solar system consists of the sun (a star), the planets and their moons, and countless smaller. Solar system belongs to the huge, disk shaped collection of stars called the milky way galaxy objects like rocky asteroids and icy comets. A galaxy is a great island of stars in space that may contain trillions of stars. Many of these stars are orbited by their own sets of planets. Groups of galaxies with more than a few dozen large members are called galaxy clusters. Our universe is the sum total of all matter and energy, encompassing the superclusters and voids. [ universe > local supercluster > local group > milky way galaxy > solar system > earth ] and everything within them. 1 astronomical unit (au) is earth"s average distance from the sun = 150 million km or 93 million miles.
