Maps of Lunar Hemispheres: Giving the Views of the Lunar Globe from Six Cardinal Directions in Space

32 Pages·1972·0.681 MB·English

by  Antonín Rükl (auth.)

MAPS OF LUNAR HEMISPHERES
ASTROPHYSICS AND
SPACE SCIENCE LIBRARY
A SERIES OF BOOKS ON THE RECENT DEVELOPMENTS
OF SPACE SCIENCE AND OF GENERAL GEOPHYSICS AND ASTROPHYSICS
PUBLISHED IN CONNECTION WITH THE JOURNAL
SPACE SCIENCE REVIEWS
Editorial Board
J. E. BLAMONT, Laboratoire d'Aeronomie, Verrieres, France
R. L. F. BOYD, University College, London, England
L. GOLDBERG, Kitt Peak Nat. Observatory, Tucson, Ariz., U.S.A.
C. DE JAGER, University of Utrecht, Holland
Z. KOPAL, University of Manchester, Manchester, England
G. H. LUDWIG, NASA, Goddard Space Flight Center, Greenbelt, Md., U.S.A.
R. L tiST, Institut fur Extraterrestrische Physik, Garsching-Miinchen, Germany
B. M. MCCORMAC, Lockheed Palo Alto Research Laboratory, Palo Alto, Cali/., U.S.A.
H. E. NEWELL, NASA, Washington, D.C., U.S.A.
I.. I. SEDOV, Academy of Sciences of the U.S.S.R., Moscow, U.S.S.R.
Z. SVESTKA, Freiburg im Breisgau, Germany
Secretary of the Editorial Board
W. DE GRAAFF, Sterrewacht 'Sonnenborgh', University of Utrecht, Utrecht, Holland
VOLUME 33
ANTONIN RDKL
Prague, Czechoslovakia
MAPS OF
LUNAR HEMISPHERES
GIVING THE VIEWS OF THE LUNAR GLOBE
FROM SIX CARDINAL DIRECTIONS IN SPACE
WITH A FOREWORD BY
ZDENEK KOPAL
EXIRA
MATERIALS
extras.springer.com
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
Library of Congress Catalog Card Number 77-179896
ISBN 978-94-010-2881-3 ISBN 978-94-010-2879-0 (eBook)
DOl 10 .1007/978-94-010-2879-0
All Rights Reserved
Copyright (Booklet) © 1972 by Springer Science+Business Media Dordrecht
Originally published by D. Reidel Publishing Company, Dordrecht, Holland in 1972
Softcover reprint of the hardcover 1st edition 1972
No part of this book may be reproduced in any form, by print, photoprint, microfilm,
or any other means, without written permission from the publisher
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TABLE OF CONTENTS
MAPPING OF THE MOON - Foreword by Zdenek Kopal
MAPS OF LUNAR HEMISPHERES 5
1. Coordinates of Places on the Lunar Surface 5
2. Orientation of the Six Maps of the Lunar Hemisphere and their
Representation 6
3. Construction of the Maps 7
4. Lunar Nomenclature 8
I NDEX OF NAMED FORMATIONS 12
MAPPING OF THE MOON
Manned landings on the Moon since 1969 have invoked new widespread interest
on the part of lay as well as scientific public in our satellite and in the topography of its
surface. The origin of human interest in details visible on the lunar surface goes back
much further in the annals of history, and antedates the advent of telescopic astronomy
in the early years of the 17th century. The Moon became, in fact, the first celestial body
(other than the Earth) whose surface invited description in cartographic form. The
first map of the Moon which came down to us - by William Gilbert (1540-1603) - must
have been completed almost ten years before Galileo Galilei or Thomas Harriott
turned their early telescopes to the Moon in 1609 and depicted for us what they saw.
Since that time up to the past ten years, astronomical telescopes have remained our
only link with our satellite, and the sole source of information on the topography of its
surface; their increasing power of resolution has enabled us to make the degree of
this acquaintance progressively more intimate. In the early part of the 17th century
- at the time of Galileo Galilei - the optical power of telescopes then available enabled
the early observers to resolve on the Moon details some 20-25 km in size. In the
3t centuries which elapsed since that time a greatly increased optical resolution of
astronomical telescopes permitted resolution on the lunar surface, at favourable times,
of details down to about 300 m. Below this limit, the telescopic outlines of individual
surface features become irretrievably blurred in a haze arising from the diffraction
of light (due to finite aperture of the telescope), unsteadiness of atmospheric 'seeing',
or photographic plate grain.
Moreover, due to the synchronism between the axial rotation of our satellite and
its revolution around the Earth, only one-half of its face is accessible to direct ob
servation at any particular time. It is true that, on account of librations exhibited
by our satellite in the course of its motion, not less than 59% of the entire lunar globe
can be seen from the Earth at one time or another; only 41% being permanently in
visible; and an equal amount never disappearing; the remainder being alternately
visible and invisible. The Moon does not, therefore, show us always exactly the same
face; only approximately so; but the limb regions are usually seen in so fore
shortened a form that the amount of detail recognisable then from the Earth is severely
limited.
A dramatic emergence of long-range space probes since 1959 has thoroughly
changed the situation. On 7th of October 1959 - a memorable date in the annals of
our science - the Russian spacecraft Luna 3 unveiled for us for the first time some of
the principal features of a major part of the Moon's far side (to a resolution compar
able with that of Galileo's first lunar observations in 1609); and subsequent space
craft that followed in rapid succession soon overshadowed this initial exploit in
2 MAPS OF LUNAR HEMISPHERES
range as well as accuracy. In particular, the American Lunar Orbiters 1-5 of 1966-
1968 have provided us with an almost complete photographic coverage of the lunar
surface, on a resolution far greater than that attainable by any existing telescopes
from the distance of the Earth.
This is not the place in which to give a description of more technical aspects of
these spacecraft. Suffice it to say that almost the entire surface of the Moon (with the
exception of a small patch of lunar ground near the south pole) of 38 million km2 was
photographed by them largely from overhead vantage points (thus obviating the
effects of foreshortening) with a resolution between 100-200 m on the lunar surface;
while almost 100000 km2 of the lunar front side was photographed by the Orbiters'
large-aperture optics to a ground resolution of a few meters. As a result of this highly
successful programme - augmented since by a large amount of additional photo
graphy taken during the orbital stages of subsequent Apollo missions - we now possess
a photographic coverage of the lunar surface almost as complete as aerial photography
surveys of our own Earth.
This total wealth of new topographic data, which has so suddenly come in our
possession, has so far been utilized only to a limited extent for the purposes of lunar
cartography; and the present new maps of the Moon constructed by Ing. Antonin Riikl,
represent a significant contribution to the subject accomplished with their aid. His
contribution can, moreover, claim originality not only by virtue of the novelty of the
material on which his work was based, but also by the new way of its presentation. His
six maps present to the reader the Moon as it would look from six mutually perpendi
cular cardinal directions in space - its near and far side, its eastern and western hemi
spheres, as well as the hemispheres seen from both poles. Not many people may hope
to see the Moon from all these vantage points within our lifetime. However, space
craft created by human hand have already seen it for us through their cameras; and
of what they saw, Riikl's maps give (on their scale) a full and faithful account. His
maps Nos. 2 and 4-6 of the Moon as seen from the East and West, as well as from
both poles, are the first of their kind in the world selenographicalliterature.
Antonin Riikl is, moreover, the first selenographer to have adopted for his work the
Lambert azimuthal representation - i.e., one permitting him to project the actual
lunar hemispheres on to plane maps, on which the relative areas of all parts are directly
comparable on the same scale. This constitutes an attractive feature for a more general
user interested mainly in appearances, and even more so for serious students of
quantitative properties of the surface of our satellite.
Another important and useful feature of Riikl's present maps is the fact that they are
provided with the latest version of the nomenclature describing diverse lunar forma
tions on both the front and far side of our satellite. Its details will be explained to us
by Riikl more fully in the second part of this introduction; here we wish to mention
briefly its origin and aims.
The origin of the nomenclature now in use on the lunar surface -like on the Earth -
was purely utilitarian and mnemotechnic: namely, to facilitate reference to individual
features in terms more picturesque than numerical values of local coordinates (the
MAPPING OF THE MOON 3
latter were not introduced to the Moon till around 1750 by Tobias Mayer). While
the terrestrial geographic terminology had taken many centuries for its development,
the parallel evolution on the Moon had much less time at its disposal so far.
The first attempt to name formations seen on the Moon goes back to William Gilbert
before 1603; though it extended only to spots visible with the naked eye. In contrast
to Plutarch (and later Galileo), Gilbert regarded the predominant bright regions on
the Moon to be seas, and dark regions as continents - possibly because he may
have thought that seas predominated on the Moon as they did on the surface of the
Earth. One lunar 'sea' well-known to us - Mare Crisium near the northeast limb of the
visible face of our satellite - received from Gilbert the name of 'Britannia'; but other
regions named by him are difficult to identify on our maps today.
Galileo Galilei - rather surprisingly - did not name any feature on the Moon,
described by him in general terms in his Sidereus Nuncius of 1610; and neither did
Thomas Harriott (the latter referred to lunar features marked on his drawings by
numbers). The first attempts at selenographic terminology in the telescopic era - by
Langren (1645) or Hevelius (1647) - were based on heraldry or other similar ephemeral
considerations; and as such are of only historical interest today. They do offer, how
ever, some points of interest; and one can only marvel at the serendipity which led
Hevelius in 1647 to bestow on the northern shores of the future Mare Tranquillitatis
- the region where the first men landed on the Moon in July 1969 - the name of
'Apollonia'.
The system of lunar nomenclature which eventually took root was that of Giovanni
Battista Riccioli (1651), because it was also the first to be based on some logical
scheme. In order to describe the lunar face, Riccioli used the names of philosophers
and scholars (rather than of princes or other potentates) of antiquity -like Pythagoras
or Thales, Aristoteles or Plato, and Archimedes with Aristarchus or Herodotus - to
bestow on craters of the Moon's northern hemisphere; while the southern hemisphere
became the domain of the famous savants of the Renaissance - like Copernicus,
Regiomontanus, or Tycho - rubbing shoulders with saints (Theophilus, Cyrillus, or
Catharina) and distinguished ecclesiastics (Clavius). Moreover, the names of the
pupils and other epigons of great men were (in several instances) given by Riccioli to
smaller formations in the neighbourhood of those called after their masters; so that
they could continue to sit symbolically at their feet on the Moon as well.
Riccioli was also the first selenographer to respect the principle of bestowing on
lunar formations only the names of the savants of the past. Unlike Langren (who
called one of the largest visible craters after himself), Riccioli wisely abstained from
such an exhibitionism; though a crater was eventually named after him by his succes
sors. Not all principles which guided Riccioli were respected too closely by his follow
ers. The number of named lunar formations has continued, however, to grow in the
course of time. Over five hundred of these can now be found on maps of the visible
side of the Moon; and almost the same number has quite recently been appended to
the Moon's far side. A full list of these has been compiled by Ing. Riikl to accompany
his maps.
4 MAPS OF LUNAR HEMISPHERES
It is, however, rather questionable whether many of these names will be used in
practice elsewhere than on maps - especially those on the Moon's far side which can
be seen only by astronauts. Nevertheless, some will undoubtedly survive the onslaught
of digitization on scientific information in the decades and centuries to come - in the
same way as ancient names of the stars in the sky may survive side by side with their
more prosaic catalogue designations - to bear a witness to the fact that there was once
romance in the sky, and ancestor-worship on the Moon. Both may be gone with the
wind before stars have moved too far in their courses, and leave us on the Earth
seeking solace in old Roman proverb that "Res victrix diis placuit, res victa Catoni".
Manchester, England ZDENEK KOP AL