Contents
- Preface
1Science and the Universe: A Brief Tour
2Observing the Sky: The Birth of Astronomy
7Other Worlds: An Introduction to the Solar System
13Comets and Asteroids: Debris of the Solar System
14Cosmic Samples and the Origin of the Solar System
18The Stars: A Celestial Census
20Between the Stars: Gas and Dust in Space
21The Birth of Stars and the Discovery of Planets outside the Solar System
27Active Galaxies, Quasars, and Supermassive Black Holes
- AHow to Study for an Introductory Astronomy Class
- BAstronomy Websites, Images, and Apps
- CScientific Notation
- DUnits Used in Science
- ESome Useful Constants for Astronomy
- FPhysical and Orbital Data for the Planets
- GSelected Moons of the Planets
- HFuture Total Eclipses
- IThe Nearest Stars, Brown Dwarfs, and White Dwarfs
- JThe Brightest Twenty Stars
- KThe Chemical Elements
- LThe Constellations
- MStar Chart and Sky Event Resources
- Index
Key Terms
- cold dark matter
- slow-moving massive particles, not yet identified, that don’t absorb, emit, or reflect light or other electromagnetic radiation
- cosmological principle
- the assumption that, on the large scale, the universe at any given time is the same everywhere—isotropic and homogeneous
- dark energy
- an energy that is causing the expansion of the universe to accelerate; the source of this energy is not yet understood
- evolution (of galaxies)
- changes in individual galaxies over cosmic time, inferred by observing snapshots of many different galaxies at different times in their lives
- galactic cannibalism
- a process by which a larger galaxy strips material from or completely swallows a smaller one
- homogeneous
- having a consistent and even distribution of matter that is the same everywhere
- hot dark matter
- massive particles, not yet identified, that don’t absorb, emit, or reflect light or other electromagnetic radiation; hot dark matter is faster-moving material than cold dark matter
- isotropic
- the same in all directions
- Local Group
- a small cluster of galaxies to which our Galaxy belongs
- merger
- a collision between galaxies (of roughly comparable size) that combine to form a single new structure
- starburst
- a galaxy or merger of multiple galaxies that turns gas into stars much faster than usual
- supercluster
- a large region of space (more than 100 million light-years across) where groups and clusters of galaxies are more concentrated; a cluster of clusters of galaxies
- void
- a region between clusters and superclusters of galaxies that appears relatively empty of galaxies