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
- asteroid
- a stony or metallic object orbiting the Sun that is smaller than a planet but that shows no evidence of an atmosphere or of other types of activity associated with comets
- comet
- a small body of icy and dusty matter that revolves about the Sun; when a comet comes near the Sun, some of its material vaporizes, forming a large head of tenuous gas and often a tail
- differentiation
- gravitational separation of materials of different density into layers in the interior of a planet or moon
- giant planet
- any of the planets Jupiter, Saturn, Uranus, and Neptune in our solar system, or planets of roughly that mass and composition in other planetary systems
- half-life
- time required for half of the radioactive atoms in a sample to disintegrate
- meteor
- a small piece of solid matter that enters Earth’s atmosphere and burns up, popularly called a shooting star because it is seen as a small flash of light
- meteorite
- a portion of a meteor that survives passage through an atmosphere and strikes the ground
- planetesimals
- objects, from tens to hundreds of kilometers in diameter, that formed in the solar nebula as an intermediate step between tiny grains and the larger planetary objects we see today; the comets and some asteroids may be leftover planetesimals
- radioactivity
- process by which certain kinds of atomic nuclei decay naturally, with the spontaneous emission of subatomic particles and gamma rays
- solar nebula
- the cloud of gas and dust from which the solar system formed
- terrestrial planet
- any of the planets Mercury, Venus, Earth, or Mars; sometimes the Moon is included in the list