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
- apparent solar time
- time as measured by the position of the Sun in the sky (the time that would be indicated by a sundial)
- declination
- the angular distance north or south of the celestial equator
- great circle
- a circle on the surface of a sphere that is the curve of intersection of the sphere with a plane passing through its center
- International Date Line
- an arbitrary line on the surface of Earth near longitude 180° across which the date changes by one day
- lunar eclipse
- an eclipse of the Moon, in which the Moon moves into the shadow of Earth; lunar eclipses can occur only at the time of full moon
- mean solar time
- time based on the rotation of Earth; mean solar time passes at a constant rate, unlike apparent solar time
- meridian
- a great circle on the terrestrial or celestial sphere that passes through the poles
- phases of the Moon
- the different appearance of light and dark on the Moon as seen from Earth during its monthly cycle, from new moon to full moon and back to new moon
- right ascension
- the coordinate for measuring the east-west positions of celestial bodies; the angle measured eastward along the celestial equator from the vernal equinox to the hour circle passing through a body
- sidereal day
- Earth’s rotation period as defined by the positions of the stars in the sky; the time between successive passages of the same star through the meridian
- sidereal month
- the period of the Moon’s revolution about Earth measured with respect to the stars
- solar day
- Earth’s rotation period as defined by the position of the Sun in the sky; the time between successive passages of the Sun through the meridian
- solar eclipse
- an eclipse of the Sun by the Moon, caused by the passage of the Moon in front of the Sun; solar eclipses can occur only at the time of the new moon
- solar month
- the time interval in which the phases repeat—say, from full to full phase
- synchronous rotation
- when a body (for example, the Moon) rotates at the same rate that it revolves around another body
- tides
- alternate rising and falling of sea level caused by the difference in the strength of the Moon’s gravitational pull on different parts of Earth