Sky & Telescope - December 2023 - 53

Schröter made hundreds of drawings of
particular features and regions of the
Moon, discovering more details than
ever before, including mare ridges and
rilles, and coined the term " crater. " The
35-km-wide crater Schröter is found
between Copernicus and Ptolemaeus.
A high point of lunar mapping was
2
1. Galilaei
2. Langrenus
3. Hevelius
4. Grimaldi
5. Riccioli
6. T. Mayer
7. Lichtenberg
8. Schröter
9. Beer
10. Mädler
11. Loewy
12. Puiseux
13. Blagg
14. Müller
15. Kuiper
16. Shoemaker
the publication of four quadrant maps
beginning in 1834 and a single volume,
Der Mond, in 1837. The authors were
Wilhelm Beer and Johann Mädler, but
nearly all the work was accomplished
by Mädler using Beer's observatory and
3.75-inch refractor. Mädler's map was
the best created up to then. With it he
refined and extended Riccioli's nomenclature.
But more importantly, Der Mond
was the first modern scientific study of
the Moon with detailed descriptions of
all named features, including the sizes of
craters and mountains as well as theories
of the origins of surface features. The
28-km-wide crater Mädler is just east of
Theophilus, while the 10-km-pit Beer is
found in Mare Imbrium, southwest of
Archimedes.
Telescopic photography changed
features, making his the most accurate
map of the time. Mayer's 1749 chart
was not published until 1775 by Georg
Lichtenberg, who added a latitude and
longitude grid. The flat-floored, 33-kmdiameter
crater T. Mayer is found at
the western end of Montes Carpatus,
while the 20-km crater Lichtenberg is
northwest of the Aristarchus Plateau in
northern Oceanus Procellarum.
Although he planned to make a
map of the entire Moon, the German
observer Johann Schröter ended up
publishing two large volumes, Selenographische
Fragmente, in 1791 and 1802
that took selenology - the scientific
study of the Moon - in a new direction.
lunar cartography with two seminal
works. The first was the L'Atlas photographique
de la Lune, a selection of 80
large photographic prints taken with
the Paris Observatory's 24-inch refractor.
French astronomers Maurice Loewy
and Pierre Puiseux produced their atlas
between 1894 and 1908. The 22-km
ghost crater Loewy and the ghostlike
25-km Puiseux are found in the
northeast and southern extent of Mare
Humorum, respectively.
Despite these advances, hand-drawn
maps weren't rendered completely obsolete.
The Named Lunar Formations map
and its accompanying catalog by Mary
Blagg and Karl Müller, published in
1935, resolved numerous conflicts, confusions,
and double-naming of craters
that had accumulated over the previous
centuries. Blagg is a 5-km crater
found in Sinus Medii; 24-km Müller is
a much older and battered crater found
just east of Ptolemaeus.
The second and possibly most
influential photographic map was the
Photographic Lunar Atlas compiled under
the direction of Gerard Kuiper of the
Lunar and Planetary laboratory in 1960.
This atlas used the best photographs
from several major observatories and
included four different illumination
angles for each of its 44 fields. Kuiper
is a 7-km crater found in Mare Cognitum.
His atlas was used to measure
positions and diameters of craters for
the System of Lunar Craters that I coauthored
as an undergraduate student.
The System was accepted as the 2nd
official International Astronomical
Union lunar map and catalog, though
no crater was named for David Arthur,
the project leader.
During the 1960s and into the
1970s, a totally different type of map
was created by Eugene Shoemaker and
his colleagues at the United States
Geological Survey (USGS). The Geologic
Atlas of the Moon was a series of 88
maps at 1:1 million scale depicting the
stratigraphy of all lunar features, from
the youngest to the most ancient. Of all
lunar maps made previously, this series
incorporates the most science, and just
recently it was updated and combined
into the USGS Unified Global Geologic
Map of the Moon (see the August issue,
p. 52). The 51-km crater Shoemaker is
the most difficult crater named after a
Moon mapper to observe. It's nearly at
the lunar south pole, and only occasionally
is its rim visible telescopically.
The most advanced and useful
Moon map is the Lunar Reconnaissance
Orbiter (LRO) QuickMap
(https://quickmap.lroc.asu.edu). This
excellent digital atlas uses LRO images
that form a complete, high-resolution
global mosaic. Other data sets -
including the USGS maps - can be set
to overlay the LRO images, enhancing
the site's utility. Mark Robinson is the
leader of the LRO team - fortunately
there's no lunar crater named for him,
since one needs to be dead three years
before that honor can be bestowed, and
Mark is still young!
¢Contributing Editor CHUCK WOOD
spends lots of time on cloudy nights
exploring the Moon with the LRO QuickMap
website.
sk yand tele scope .o r g * DECEMBER 2023 53
https://quickmap.lroc.asu.edu https://skyandtelescope.org/
Sky & Telescope - December 2023

Table of Contents for the Digital Edition of Sky & Telescope - December 2023
