NATS 1585 Lecture Notes - Lecture 2: Equinox, Angular Diameter, Top
Document Summary
Nats 1585 lecture 2: chapter 1 and 2. A large, glowing ball of gas that generates heat and light through nuclear fusion. A moderately large objects that orbits a star; it shines by reflected light. Planets may be rocky, icy, or gaseous in composition. Relatively small and rocky object that orbits a star. There are around five dwarf planets in the solar system. They are in outer solar systems except ceres. Not cleaned their orbits yet (they become bigger) Relatively small and icy object that orbits a star. A star and all the material that orbits. An interstellar cloud of gas and/or dust. A great island of stars in space, all held together by gravity and orbiting a common center. The sum total of all matter and energy; that is everything within and between all galaxies. 73% dark energy, 23% dark matter, 3. 6% intergalactic gas, 0. 4% stars etc. Light travel time distance the further back we look in time.