A Field Guide to the Stars and Planets (Peterson Field Guide Series) - Softcover

Pasachoff, Jay M.; Menzel, Donald H.

Softcover

ISBN 10: 0395910994 ISBN 13: 9780395910993

Publisher: Houghton Mifflin Harcourt, 1998

Synopsis

Provides detailed maps and charts and information about stars, nebulae, galaxies, the planets, comets, asteroids, and meteors

About this title

About the Author

Jay M. Pasachoff is the Field Memorial Professor of Astronomy and director of the Hopkins Observatory at Williams College in Williamstown, Massachusetts. Professor Pasachoff has done extensive research on the solar corona at total eclipses and has been on 29 eclipse expeditions. He has also used a wide variety of telescopes around the world. He is the author of popular textbooks on astronomy and on other science subjects. He has twice been chair of the Astronomy Division of the American Association for the Advancement of Science and is the chair of the Working Group on Eclipses of the International Astronomical Union and the U.S. national representative to the IAU's Commission on the Teaching of Astronomy.

Excerpt. © Reprinted by permission. All rights reserved.

The moon is often the most prominent object in the nighttime sky. The moon is somewhat more than one-quarter the diameter of the earth. This makes it the largest substantial satellite (moon) in the solar system in comparison to its parent planet. (Three moons of Jupiter and one each of Neptune and Saturn are physically larger than our moon; Pluto’s small moon Charon is nearly half Pluto’s size.) The moon orbits the earth every 271?3 days with respect to the stars. But during that time, the earth and moon have moved as a system about 1?12 of the way in their yearly orbit around the sun. So if the moon at a certain point in its orbit is directly between the earth and the sun, 271?3 days later it has not quite returned to that point directly between the earth and the sun. The moon must orbit the earth a bit farther to get back to the same place with respect to the line between the earth and the sun. The moon reaches this point in a couple of days, making the synodic period of the moon equal to 291?2 days. (The synodic period is the interval between two successive conjunctions coming to the same celestial longitude of two celestial bodies, in this case conjunctions of the moon and sun as observed from the earth.) It is the synodic months that are taken into account in lunar calendars.

Edition details

• Publisher: Houghton Mifflin Harcourt
• Publication date: 1998
• Language: English
• ISBN 10: 0395910994
• ISBN 13: 9780395910993
• Binding: Paperback
• Number of pages: 502