ASTRONOMICALALGORITHMS
,ASTRONOMICAL
WMWIH1III .1. 1J U. s m Wiwu
ALGORITHMS
Jean Meeus
TM
Wllmann-Bell, Inc,
P.O. Box 35025 • Richmond, Virginia 23235 • B (804) 320-7016 • FAX (804) 272-5920
www.willbell.com
,Published by Willmann-Bell, Inc.
P.O. Box 35025, Richmond, Virginia 23235
Copyright © 1991 and 1998 by Willmann-Bell, Inc.
First English Edition 1991
Second English Edition 1998
All rights reserved. Except for brief passages quoted in a review, no part of this
book may be reproduced by any mechanical, photographic, or electronic process,
nor may it be stored in any information retrieval system, transmitted, or otherwise
copied for public or private use, without the written permission of the publisher.
Requests for permission or further information should be addressed to Permis
sions Department, Willmann-Bell, Inc. P.O. Box 35025, Richmond, VA 23235.
Printed in the United States of America
Library of Congress Cataloging-in-Publication Data.
Meeus, Jean.
Astronomical algorithms / Jean Meeus. — 2nd ed.
p. cm.
Includes bibliographical references and index.
ISBN 0-943396-61-1
1. Astronomy - Data processing. 2. Astronomy - Problems, exercises,
etc. 3. Algorithms. I. Title.
QB51.3.E43M42 1998 98-55091
520’.285-dc21 CIP
98 99 00 01 02 03 04 05 06 9 876543 2 1
, Foreword (to the first edition)
People who write their own computer programs often wonder why the machine
gives inaccurate planet positions, an unreal eclipse track, or a faulty Moon
phase. Sometimes they insist, bewildered, “and I used double precision, too.”
Even commercial software is sometimes afflicted with gremlins, which comes as
quite a shock to anyone caught up in the mystique and presumed infallibility of
computers. Good techniques can help us avoid erroneous results from a flawed
program or a simplistic procedure — and that’s what this book is all about.
In the field of celestial calculations, Jean Meeus has enjoyed wide acclaim
and respect since long before microcomputers and pocket calculators appeared
on the market. When he brought out his Astronomical Formulae for Calculators
in 1979, it was practically the only book of its genre. It quickly became the
“source among sources”, even for other writers in the field. Many of them have
warmly acknowledged their debt (or should have), citing the unparalleled clarity
of his instructions and the rigor of his methods.
And now this Belgian astronomer has outdone himself yet again! Virtually
every previous handbook on celestial calculations (including his own earlier
work) was forced to rely on formulae for the Sun, Moon, and planets that were
developed in the last century — or at least before 1920. The past 10 years,
however, have seen a stunning revolution in how the world’s major observatories
produce their almanacs. The Jet Propulsion Laboratory in California and the
U.S. Naval Observatory in Washington, D.C., have perfected powerful new
machine methods for modeling the motions and interactions of bodies within the
solar system. At the same time in Paris, the Bureau des Longitudes has been a
beehive of activity aimed at describing these motions analytically, in the form of
explicit equations.
Yet until now the fruits of this exciting work have remained mostly out of
reach of ordinary people. The details have existed mainly on reels of magnetic
tape in a form comprehensible only to the largest brains, human or electronic.
But Astronomical Algorithms changes all that. With his special knack for
computations of all sorts, the author has made the essentials of these modern
techniques available to us all.
,ASTRONOMICAL
WMWIH1III .1. 1J U. s m Wiwu
ALGORITHMS
Jean Meeus
TM
Wllmann-Bell, Inc,
P.O. Box 35025 • Richmond, Virginia 23235 • B (804) 320-7016 • FAX (804) 272-5920
www.willbell.com
,Published by Willmann-Bell, Inc.
P.O. Box 35025, Richmond, Virginia 23235
Copyright © 1991 and 1998 by Willmann-Bell, Inc.
First English Edition 1991
Second English Edition 1998
All rights reserved. Except for brief passages quoted in a review, no part of this
book may be reproduced by any mechanical, photographic, or electronic process,
nor may it be stored in any information retrieval system, transmitted, or otherwise
copied for public or private use, without the written permission of the publisher.
Requests for permission or further information should be addressed to Permis
sions Department, Willmann-Bell, Inc. P.O. Box 35025, Richmond, VA 23235.
Printed in the United States of America
Library of Congress Cataloging-in-Publication Data.
Meeus, Jean.
Astronomical algorithms / Jean Meeus. — 2nd ed.
p. cm.
Includes bibliographical references and index.
ISBN 0-943396-61-1
1. Astronomy - Data processing. 2. Astronomy - Problems, exercises,
etc. 3. Algorithms. I. Title.
QB51.3.E43M42 1998 98-55091
520’.285-dc21 CIP
98 99 00 01 02 03 04 05 06 9 876543 2 1
, Foreword (to the first edition)
People who write their own computer programs often wonder why the machine
gives inaccurate planet positions, an unreal eclipse track, or a faulty Moon
phase. Sometimes they insist, bewildered, “and I used double precision, too.”
Even commercial software is sometimes afflicted with gremlins, which comes as
quite a shock to anyone caught up in the mystique and presumed infallibility of
computers. Good techniques can help us avoid erroneous results from a flawed
program or a simplistic procedure — and that’s what this book is all about.
In the field of celestial calculations, Jean Meeus has enjoyed wide acclaim
and respect since long before microcomputers and pocket calculators appeared
on the market. When he brought out his Astronomical Formulae for Calculators
in 1979, it was practically the only book of its genre. It quickly became the
“source among sources”, even for other writers in the field. Many of them have
warmly acknowledged their debt (or should have), citing the unparalleled clarity
of his instructions and the rigor of his methods.
And now this Belgian astronomer has outdone himself yet again! Virtually
every previous handbook on celestial calculations (including his own earlier
work) was forced to rely on formulae for the Sun, Moon, and planets that were
developed in the last century — or at least before 1920. The past 10 years,
however, have seen a stunning revolution in how the world’s major observatories
produce their almanacs. The Jet Propulsion Laboratory in California and the
U.S. Naval Observatory in Washington, D.C., have perfected powerful new
machine methods for modeling the motions and interactions of bodies within the
solar system. At the same time in Paris, the Bureau des Longitudes has been a
beehive of activity aimed at describing these motions analytically, in the form of
explicit equations.
Yet until now the fruits of this exciting work have remained mostly out of
reach of ordinary people. The details have existed mainly on reels of magnetic
tape in a form comprehensible only to the largest brains, human or electronic.
But Astronomical Algorithms changes all that. With his special knack for
computations of all sorts, the author has made the essentials of these modern
techniques available to us all.
