AST 2002 Chapter Notes - Chapter 1: Usable Fuel, Ecliptic, Cosmic Calendar
Document Summary
Chapter 1 textbook notes: a modern view of the universe. Key terms: star- a large, glowing ball of gas that generates heat and light through nuclear fusion in its core. Our sun is a star: planet- a moderately large object that orbits a star and shines primarily by reflecting light from its star. An object that meets the first two criteria but has not cleared its orbital path, like pluto, is designated a dwarf planet: moon (or satellite)- an object that orbits a planet. Although the term solar system technically refers only to our own star system (solar means. The observable universe is probably only a tiny portion of the entire universe: astronomical unit (au)- the average distance between earth and the sun, which is about 150 million kilometers. More technically, 1 au is the length of the semimajor axis of earth"s orbit.
