Stratigraphy of Lunar Craters
Don E. Wilhelms and Charles J. Byrne
January
23, 2009
Section

Title

Page

Introduction


2

Chapter 1

The PreNectarian System

5

Chapter 2

The Nectarian System

14

Chapter 3

The Imbrian System,

30

Chapter 4

The Imbrian System,

33

Chapter 5

The Eratosthenian System

37

Chapter 6

The Copernican System

41

Chapter 7

Revised Strata Assignments

43

Appendix A

Lunar Craters Sorted by Name

A1

Appendix B

Lunar Craters Sorted by LAC Chart

B1

In 1987 the U.S. Geological
Survey (USGS) published what is still the most complete assessment of the ages
of lunar craters, The Geologic History of the Moon (GHM; USGS Professional
Paper 1348, by Don Wilhelms and two expert contributors of special sections,
John F. McCauley and Newell J. Trask). Relative ages of lunar geologic
units are determined in ways that are simple in principle if often difficult in
practice. Decades of work have established that almost all lunar craters
were created by impacts and started their existence looking pretty much alike:
a deep bowl surrounded by a rough raised rim that in turn is surrounded by
radial ejecta ridges and secondaryimpact craters. Where this pattern is
complete, the crater is probably younger than adjacent units. Where the
pattern is interrupted by another crater's ejecta or a flood of mare material,
the interrupting unit is the younger. A very powerful stratigraphic
technique derives from the observation that the largest lunar features, the
ringed impact basins, also display consistent patterns in their extensive
ejecta deposits and secondarycrater fields. A crater superposed anywhere
on these is obviously younger than the basin. Where a crater is striated or
roughened by a basin's ejecta or is pockmarked by its secondaries, that crater
is older than the basin. This is an especially valuable dating tool over wide
areas. Ejecta and mare units have also been dated relative to one another
by counts of superposed smaller craters. In the absence of good
stratigraphic control, ages of craters are estimated from their morphologies:
with time they lose their originally sharp features and steep slopes.
Age relations established by
these simple observations on Earthbased, Lunar Orbiter, and Apollo photographs
have been mapped over the whole Moon and unified into a stratigraphic column, a
classification of the succession of deposited layers. The ejecta blankets
and secondarycrater fields of the Nectaris, Imbrium, and Orientale basins
supply the main reference horizons. Six main subdivisions of this column
are defined or redefined in GHM and provide the organizing framework for the
present contribution.
By a convention long
established for Earth geology, "system" refers to all the physical
deposits formed during a period of geologic time, and "series" to all
those formed within the subdivisions of a period called an
"epoch". The specific systems and series defined for the Moon
are:
The preNectarian System includes all deposits that
are older than the Nectaris Basin.
The Nectarian System includes the Nectaris Basin and
all other basins and craters up to but not including the Imbrium Basin.
The Lower Imbrian Series is bounded below and above by
the Imbrium and Orientale basins, respectively, and also includes everything
formed in between (the spelling Imbrium refers to the physical basin and
Imbrian to age and stratigraphic position).
The Upper Imbrian Series includes deposits younger
than Orientale but older than the mare basalts sampled by Apollo 12.
The Eratosthenian System includes those basalts and
other mare and crater materials up to a roughly estimated age of 1.1 aeons
(billion years).
The Copernican System fills out the recent lunar
geologic record.
The tables in the present
document supplement and update GHM. Ages of craters 30 km and larger in
diameter are summarized in GHM on six twopart color plates, part A for the
nearside and B for the farside. Each of the six plates is devoted to one
of the systems or series. The main contribution of our document is to
give the names and coordinates of the craters mapped on the plates, especially
the many on the crowded preNectarian and Nectarian plates that were mapped but
could not be named for lack of space. For now, only the 60 km preNectarians
are listed in these tables because of doubts about the ages of smaller
ones. Following are the correspondences between the GHM plates and the
chapters in our document:
GHM Plate 
Chapter 
System 
Series 
Age 





6 
1 
PreNectarian 

>3.92 aeons 
7 
2 
Nectarian 

3.923.84 aeons 
8 
3 
Imbrian 

3.843.8 aeons 
9 
4 
Imbrian 

3.83.2 aeons 
10 
5 
Eratosthenian 

3.21.1 aeons 
11 
6 
Copernican 

<1.1 aeons 
The absolute ages (an aeon is
one billion years) are those accepted in GHM from calibrations of the relative
stratigraphy with radiometric dates measured on samples returned from the Moon.
Each chapter contains two
tables, one for the nearside craters and one for the farside. The
"Comments" in the last column of the tables correct some
errors, state remaining uncertainties, present a few new findings, note name
changes, and describe some important superposition relations between craters
and basins. The Nectarian tables, for example, contain many comments in
the form "Younger than basin X" or "Older than
basin Y" . These reflect the fact that the Nectarian System includes
a number of basins that have been ranked stratigraphically (and potentially could
subdivide the system). "Partly covered by Imbrian ejecta"
is a frequent comment as well. These relations are portrayed on the GHM
plates as follows:
Craters are mapped as circles, solid black if exposed.
If a crater is covered by a unit of ejecta or mare
material belonging to the same system or series as the crater, its color is
that of the overlying unit.
If not colored, the overlying unit belongs to a
younger age category than the crater and is mapped in color on one of the
highernumbered plates.
Important examples are the
large blank areas on both the preNectarian and Nectarian plates (6 and 7,
respectively), that correspond to the ejecta blankets of the Imbrium and
Orientale basins; these are Lower Imbrian and thus mapped in color on Plate
8. Nectarian basins mapped in color on Plate 7 add to the blank areas of
the preNectarian plate.
Most positions and sizes
given in our tables were originally compiled at the Lunar and Planetary
Laboratory, University of Arizona, by Leif Andersson and Ewen Whitaker (NASA
Catalogue of Lunar Nomenclature, NASA Reference Publication 1097, 1982).
Some comments in our tables reflect nomenclature used by NASA. Some of these
names were changed or modified by subsequent actions of the International
Astronomical Union (IAU). The complete IAU list includes a very large
number of names, some for craters as small as 1 km in diameter. The
NASA system includes lettered names of satellitic craters
arrayed around a patronymic, an easily workable system initiated by Johann
Mädler in the 19th century and developed and refined by Ewen Whitaker.
The AnderssonWhitaker positions and names have been recompiled in The
Clementine Atlas of the Moon (by Ben Bussey and Paul Spudis, Cambridge
University Press, 2004). The USGS Web page (http://planetarynames.wr.usgs.gov/)
also gives the positions and sizes for the named craters and the lettered ones
of the catalog (a recent addition). This web site lists the lettered craters as
"satellite features". It also identifies the people (mostly
scientists) for whom the craters are named. It includes the diverse
diacritical marks that are important in many names but are absent from the
AnderssonWhitaker and Clementine lists. Our tables give both the current
and superseded names where necessary, as clarified in the Comments
column. Some craters listed in the tables do not appear in the NASA,
USGS, or Clementine lists but were found on one of the airbrushed charts
published by various agencies that were used in the preparation of GHM; this is
the meaning of the comment "not in catalog".
The very useful Clementine
atlas is conveniently organized. The Clementine images and airbrushed charts
are displayed in 144 twopage sections, each based on one of the
1:1,000,000scale charts originally planned early in the Space Age by the U.S.
Air Force Aeronautical Chart and Information Center (ACIC) to cover the whole
Moon. One of the Clementine pages shows the Clementine orbital image of
each Lunar Aeronautical Chart (LAC) area and the other a redrawing of the LAC,
with feature names. The Clementine gazetteer and our tables refer to the
LAC on which each crater is depicted. The LAC numbers for lettered names
in the catalog and the Clementine atlas sometimes refer to the LAC on which
their patronymic crater appears. These have often been changed in our tables to
designate the LAC for the specific lettered crater. In a few cases
corrections have been made to the designated LAC number.
GHM and this contribution are
progress reports. Even now, fifty years after it was first imaged by
spacecraft and after intense study by the
In addition to the tables for
each of the plates in the GHM, there is a table in Chapter 7 that lists craters
whose stratagraphic assignment has been changed from that in the GHM because of
new understanding, new images from Clementine, or reconsideration. Appendix A
lists all of the craters documented in the main body in alphabetical order,
with their coordinates, LAC charts, strata and comments; it serves as an index
for the main body. Appendix B lists the craters sorted by their LAC chart
numbers, so that all the craters centered in each LAC are grouped together with
their strata and comments. This appendix is intended to aid in comparison of
the topography of craters of different ages.
Table 1.1 PreNectarian System, Nearside, Plate 6A 

Feature 
Latitude 
Longitude 
Diam. (km) 
LAC 
Comments 






Abel 
34.5 S 
87.3 E 
122 
116 

Abel M 
32.2 S 
83.6 E 
81 
116 

Alexander 
40.3 N 
13.5 E 
81 
26 

Amundsen A 



144 
Renamed
Hêdervâri 
Anaximander 
66.9 N 
51.3 W 
67 
2 

Anaximander B 
67.8 N 
60.7 W 
78 
2 

Anaximander D 
65.4 N 
50.1 W 
92 
2 

Anaximenes 
72.5 N 
44.5 W 
80 
2 


66.8 N 
35.9 E 
94 
4 

Babbage 
59.7 N 
57.1 W 
143 
10 

Babbage D 
58.6 N 
61.0 W 
68 
10 

Baco 
51.0 S 
19.1 E 
69 
127 
Probably
Nectarian; should be shown on Plate 7A, not 6A 
Baillaud 
74.6 N 
37.5 E 
89 
4 

Balboa 
19.1 N 
83.2 W 
69 
37 
Probably
Nectarian; should be shown on Plate 7A, not 6A 
Balboa B 
20.3 N 
82.3 W 
62 
37 

Balmer 
20.3 S 
69.8 E 
138 
98 
Name is on LAC
99 
Barnard 
29.5 S 
85.6 E 
105 
99 
Possibly
Nectarian 
Barrow 
71.3 N 
7.7 E 
92 
3 
Possibly
Nectarian 

65.1 N 
10.5 W 
92 
3 

Boguslawsky 
72.9 S 
43.2 E 
97 
138 

Boguslawsky B 
73.9 S 
61.0 E 
63 
139 

Bohr 
12.4 N 
86.6 W 
71 
55 

Bonpland 
8.3 S 
17.4 W 
60 
76 

Boole 
63.7 N 
87.4 W 
63 
21 

Boole H 
61.6 N 
88.9 W 
75 
21 

Boussingault 
70.2 S 
54.6 E 
142 
138 

Boussingault E 
67.2 S 
46.8 E 
98 
138 

Brenner 
39.0 S 
39.3 E 
97 
114 

Brianchon 
75.0 N 
86.2 W 
134 
9 


52.8 S 
72.4 E 
64 
129 

Byrd 
85.3 N 
9.8 E 
93 
1 

Casatus 
72.8 S 
29.5 W 
108 
137 

Clairaut 
47.7 S 
13.9 E 
75 
113 

Curtius D 
64.8 S 
8.1 E 
61 
137 

Cuvier 
50.3 S 
9.9 E 
75 
126 


20.2 S 
69.5 W 
120 
92 

Davy Y 
11.0 S 
7.1 W 
70 
77 

De La Rue 
59.1 N 
52.3 E 
134 
14 

De Sitter L 
78.8 N 
34.5 E 
69 
4 

Desargues 
70.2 N 
73.3 W 
85 
2 

Deslandres 
33.1 S 
4.8 W 
256 
112 
Name is on LAC
95 
Drebbel E 
38.1 S 
51.3 W 
65 
110 

Drygalski 
79.3 S 
84.9 W 
149 
143 

Eddington 
21.3 N 
72.2 W 
118 
37 

Einstein 
16.3 N 
88.7 W 
198 
37 

Endymion J 
53.5 N 
50.7 E 
67 
14 

Encke T 
3.4 N 
38.0 W 
91 
57 
May not be a
crater 
Euclides P 
4.5 S 
27.6 W 
66 
76 

Euctemon 
76.4 N 
31.3 E 
62 
4 

Faraday 
42.4 S 
8.7 E 
69 
112 

Fernelius 
38.1 S 
4.9 E 
65 
112 

Flammarion 
3.4 S 
3.7 W 
74 
77 

Flamsteed P 
3.2 S 
44.1 W 
112 
75 
Possibly
Nectarian 
Fra Mauro 
6.1 S 
17.0 W 
101 
76 

Fraunhofer J 
42.4 S 
63.6 E 
63 
115 

Furnerius 
36.0 S 
60.6 E 
135 
115 

Gärtner 
59.1 N 
34.6 E 
115 
13 

Gauricus 
33.8 S 
12.6 W 
79 
112 

Gemma Frisius 
34.2 S 
13.3 E 
87 
113 

Gemma Frisius A 
35.8 S 
15.2 E 
68 
113 

Gerard 
44.5 N 
80 W 
90 
22 

Gilbert 
3.2 S 
76.0 E 
112 
81 

Gill 
63.9 S 
75.9 E 
66 
129 

Goldschmidt 
73.2 N 
3.8 W 
113 
3 

Grimaldi 
5.5 S 
68.3 W 
172 
74 

Gruemberger 
66.9 S 
10.0 W 
93 
137 

Guericke 
11.5 S 
14.1 W 
63 
76 

Hagecius 
59.8 S 
46.6 E 
76 
128 

Hagecius A 
58.2 S 
47.2 E 
61 
128 

Harlan 
38.5 S 
79.5 E 
65 
115 

Hartwig 
6.1 S 
80.5 W 
79 
73 

Hecataeus B 
19.5 S 
75.6 E 
69 
99 

Hecataeus K 
19.1 S 
79.8 E 
76 
99 

Hêdervâri 
81.8 S 
84.0 E 
69 
144 
Formerly
Amundsen A 
Hedin 
2.0 N 
76.5 W 
150 
55 

Hedin A 
5.5 N 
78.1 W 
60 
55 

Heinsius 
39.5 S 
17.7 W 
64 
111 

Helmholtz 
68.1 S 
64.1 E 
94 
139 

Heraclitus 
49.2 S 
6.2 E 
90 
126 

Hermite 
86.0 N 
89.9 W 
104 
1 

Hipparchus 
5.1 S 
5.2 E 
138 
77 

Hommel 
54.7 S 
33.8 E 
126 
127 

J. Herschel 
62.0 N 
42.0 W 
165 
11 

Jacobi 
56.7 S 
11.4 E 
68 
127 

Janssen 
13.5 N 
28.7 E 
23 
60 

Julius Caesar 
9.0 N 
15.4 E 
90 
60 
Possibly
Nectarian 
Käastner 
6.8 S 
78.5 E 
108 
81 

Kiess 
6.4 S 
84.0 E 
63 
81 

Klaproth 
69.8 S 
26.0 W 
119 
137 

La Caille 
23.8 S 
1.1 E 
67 
95 

Lagalla 
44.6 S 
22.5 W 
85 
111 

Lagrange 
32.3 S 
72.8 W 
225 
109 

Lagrange R 
31.3 S 
76.5 W 
130 
91 
Covered by
Orientale Basin ejecta; may not be crater 
Lamarck 
22.9 S 
69.8 W 
100 
92 

Lamarck D 
25.0 S 
74.1 W 
131 
91 

Lavoisier 
38.2 N 
81.2 W 
70 
22 
Possibly
Nectarian or younger 
Le Gentil 
74.6 S 
75.7 W 
128 
136 
May not be a
crater 
Legendre 
28.9 S 
70.2 E 
78 
99 

Legendre K 
29.8 S 
72.8 E 
90 
99 

Licetus 
47.1 S 
6.7 E 
74 
112 

Longomontanus Z 
50.0 S 
18.7 W 
95 
126 

Lyot 
49.8 S 
84.5 E 
132 
129 

Lyot H 
51.4 S 
78.2 E 
63 
129 

Lyot L 
54.4 S 
83.1 E 
70 
129 

Maestlin R 
3.5 N 
41.5 W 
61 
57 

Maginus 
50.5 S 
6.3 W 
194 
126 

Malapert 
84.9 S 
12.9 E 
69 
144 

Manzinus 
67.7 S 
26.8 E 
98 
138 

Mee 
43.7 S 
35.3 W 
126 
111 

Messala 
39.2 N 
60.5 E 
125 
28 

Meton 
73.6 N 
18.8 E 
130 
4 

Meton C 
70.6 N 
19.0 E 
77 
4 

Meton D 
72.2 N 
24.7 E 
78 
4 

Montanari 
45.8 S 
20.6 W 
76 
111 

Mouchez 
78.3 N 
26.6 W 
81 
3 

Murchison 
5.1 N 
0.1 W 
57 
59 

Mutus 
63.6 S 
30.1 E 
77 
127 

Nansen F 
84.7 N 
60.0 E 
62 
1 

Nasmyth 
50.5 S 
56.2 W 
76 
124 

Nearch 
58.5 S 
39.1 E 
75 
127 

Newton A 
79.7 S 
19.7 W 
64 
137 

Newton G 
78.2 S 
18.3 W 
67 
137 

Nonius 
34.8 S 
3.8 E 
69 
112 

Oenopides 
57.0 N 
64.1 W 
67 
10 

Orontius 
40.6 S 
4.6 W 
105 
112 

Parrot 
14.5 S 
3.3 E 
70 
77 

Peary 
88.6 N 
33.0 E 
73 
1 

Peirescius 
46.5 S 
67.6 E 
61 
115 

Petermann R 
75.0 N 
56.7 E 
115 
5 

Phillips D 
25 S 
70.8 E 
61 
99 

Phillips W 
25.3 S 
72.8 E 
63 
99 

Philolaus C 
71.1 N 
32.7 W 
95 
3 

Philolaus D 
73.9 N 
27.8 W 
91 
3 

Philolaus G 
69.0 N 
23.6 W 
95 
3 

Piazzi 
36.6 S 
67.9 W 
134 
109 

Pictet 
43.6 S 
7.4 W 
62 
112 

Pictet E 
41.3 S 
7.7 W 
70 
112 

Playfair G 
24.2 S 
6.7 E 
94 
95 

Poncelet 
75.8 N 
54.1 W 
69 
2 

Poncelet C 
77.4 N 
73.7 W 
67 
2 

Pontecoulant F 
57.4 S 
67.7 E 
60 
128 

Ptolemaeus 
9.3 S 
1.9 W 
164 
77 

Purbach 
25.5 S 
2.3 W 
115 
95 

Rabbi Levi 
34.7 S 
23.6 E 
81 
113 

Rayleigh 
29.3 N 
89.6 E 
114 
45 

Regiomontanus 
28.3 S 
1.0 W 
108 
95 

Repsold 
51.3 N 
78.6 W 
109 
10 
Possibly
Nectarian 
Repsold C 
48.9 N 
73.6 W 
133 
10 
Possibly
Nectarian 
Riccioli 
3.3 S 
74.6 W 
139 
73 
Possibly
Nectarian 
Riccius 
36.9 S 
26.5 E 
71 
113 

Riemann 
38.9 N 
86.8 E 
163 
29 

Rosenberger 
55.4 S 
43.1 E 
95 
128 

Rothmann G 
28.4 S 
24.3 E 
92 
96 

Russsell 
26.5 N 
75.4 W 
103 
37 

Sacrobosco 
23.7 S 
16.7 E 
98 
96 

Sasserides 
39.1 S 
9.3 W 
90 
112 

Scheiner 
60.5 S 
27.5 W 
110 
125 
Possibly
Nectarian 
Schickard 
44.3 S 
55.3 W 
206 
110 

Schiller H 
50.8 S 
37.7 W 
66 
125 

Schorr A 
20.5 S 
88.4 E 
64 
99 
Should be on
Plate 6A, not 7A 
Schumacher 
42.4 N 
60.7 E 
60 
28 
Not on Plate 6A 
Scott 
82.1 S 
48.5 E 
103 
144 

Segner 
58.9 S 
48.3 W 
67 
125 

Short 
74.6 S 
7.3.0 W 
70 
137 

Short B 
75.5 S 
5.0 W 
71 
137 

Simpelius 
7.03 S 
15.2 E 
70 
138 

Sirsalis E 
8.1 S 
56.5 W 
72 
74 

Sirsalis Z 
10.7 S 
61.9 W 
91 
74 

South 
58.0 N 
50.8 W 
104 
10 

Stöfler 
41.1 S 
6.0 E 
126 
112 

Stöfler J 
42.2 S 
2.4 E 
76 
112 

Struve 
22.4 N 
77.1 W 
164 
37 
Possibly
Nectarian 
Thebit P 
24.0 S 
5.7 W 
78 
95 
Flooded by Mare
Nubium; may not be a crater 
Vega 
45.4 S 
63.4 E 
75 
115 

Vendelinus 
16.4 S 
61.6 E 
131 
98 

Vlacq 
53.3 S 
38.8 E 
89 
127 

Volta 
53.9 N 
84.4 W 
123 
21 

W. Bond 
65.4 N 
4.5 E 
156 
3 

Walther 
33.1 S 
1.0 E 
128 
112 
Not on Plate 6A
(see entry in Table 2.1) 
Weiss 
31.8 S 
19.5 W 
66 
94 
Flooded by Mare
Nubium; may not be a crater 
Wichmann R 
6.6 S 
39.0 W 
62 
75 

Wilhelm 
43.4 S 
20.4 W 
106 
111 

Wilson 
69.2 S 
42.4 W 
69 
136 

Wurzelbauer 
33.9 S 
15.9 W 
88 
111 

Xenophanes 
57.5 N 
82.0 W 
125 
21 

Young 
41.5 S 
50.9 E 
71 
114 

Zagut 
32.0 S 
22.1 E 
84 
113 

Table 1.2 PreNectarian System, Farside, Plate 6B 

Feature 
Latitude 
Longitude 
Diam. (km) 
LAC 
Comment 





Aitken C 
14.0 S 
175.8 E 
74 
86 

Alekhin 
68.2 S 
131.3 W 
70 
142 

AlKhwarizmi B 
9.0 N 
107.4 E 
62 
64 

AlKhwarizmi G 
6.9 N 
107.1 E 
95 
64 

Alter 
18.7 N 
107.5 W 
64 
54 

Amici M 
11.8 S 
171.9 W 
105 
86 

Amici U 
8.7 S 
175.5 W 
96 
86 

Apollo 
36.1 S 
151.8 W 
537 
121 

Artamonov 
25.5 N 
103.5 E 
60 
46 

Artem'ev G 
10.3 N 
142.8 W 
60 
70 

Ashbrook 
81.4 S 
112.5 W 
156 
144 

Avicenna 
39.7 N 
97.2 W 
74 
36 

Avogardo 
63.1 N 
164.9 E 
139 
18 

Babcock 
4.2 N 
93.9 E 
99 
64 

Babcock H 
3.0 N 
96.5 E 
63 
64 

Barbier 
23.8 S 
157.9 E 
66 
103 
Likely to be
Nectarian: should be on Plate 7B, not 6B 
Becquerel 
40.7 N 
129.7 E 
65 
30 

Bĕcvář 
2.9 S 
124.5 E 
67 
83 

Beijerinck 
13.5 S 
151.8 E 
70 
85 

Berlage 
63.2 S 
162.8 W 
92 
133 

Birkhoff 
58.7 N 
146.1 W 
345 
19 

Birkhoff X 
62.1 N 
149.7 W 
77 
19 

Blackett 
37.5 S 
116.1 W 
141 
122 

Boltzmann 
81.4 S 
112.5 W 
76 
143 

Bolyai 
33.6 S 
125.9 E 
135 
117 

Bolyai L 
36.3 S 
126.2 E 
73 
117 

Bragg 
42.5 N 
102.9 W 
84 
36 

Brashear P 
76.8 S 
175.7 W 
71 
141 

Bronk 
26.1 N 
134.5 W 
64 
52 

Brouwer 
36.2 S 
126.0 W 
158 
122 
Partly covered
by Orientale ejecta, likely preNectarian, possibly Nectarian: should be
shown on Plate 6A, not 7A 
Buisson Z 
0.0 S 
112.5 E 
98 
83 

Cabannes 
60.9 S 
169.6 W 
80 
133 
Name is on LAC
132 
Cajori 
47.4 S 
168.8 E 
70 
119 

Campbell 
45.3 N 
151.4 E 
219 
31 

Carver M 
45.0 S 
126.8 E 
76 
117 

Chandler 
43.8 N 
171.5 E 
85 
32 

Chapman 
50.4 N 
100.7 W 
71 
21 

Chappell 
54.7 N 
177.0 W 
80 
18 

Chauvenet J 
13.9 S 
139.3 E 
77 
84 

Chretien 
45.9 S 
162.9 E 
88 
119 

Chretien C 
44.5 S 
165.3 E 
63 
119 

Cockcroft 
31.3 N 
162.6 W 
93 
51 

Comrie K 
22.1 N 
112.3 W 
73 
53 

Comstock 
21.8 N 
121.5 W 
72 
53 

Crommelin 
68.1 S 
146.9 W 
94 
142 

Curie 
22.9 S 
91.0 E 
151 
100 

Cyrano 
20.5 S 
157.7 E 
80 
103 
Possibly
Nectarian 
Daedalus C 
4.1 S 
178.9 W 
68 
86 

Daedalus W 
3.5 S 
177.5 E 
70 
86 

Danjon X 
10.0 S 
122.8 E 
65 
83 

Debye 
49.6 N 
176.2 W 
142 
18 

Dellinger 
6.8 S 
140.6 E 
81 
84 

Denning R 
17.2 S 
141.2 E 
72 
102 

Deutsch 
24.1 N 
110.5 E 
66 
47 

Duner 
44.8 N 
179.5 E 
62 
33 

Dyson Q 
59.8 N 
125.7 W 
89 
20 

Edison 
25 N 
99.1 E 
62 
46 

Elvey 
8.8 N 
100.5 W 
74 
72 

Emden 
63.3 N 
177.3 W 
111 
18 

Engelhardt B 
8.3 N 
157.7 W 
136 
69 

Eötvös 
35.5 S 
133.8 E 
99 
118 

Erro 
5.7 N 
98.5 E 
61 
64 

EsnaultPelterie 
47.7 N 
141.4 W 
79 
34 

Espin 
28.1 N 
109.1 E 
75 
46 

Evans 
9.5 S 
133.5 W 
67 
88 

Evans Q 
11.2 S 
136.4 W 
137 
88 

Evershed 
35.7 N 
159.5 W 
66 
33 

Fabry 
42.9 N 
100.7 E 
184 
29 

Fermi 
19.3 S 
122.6 E 
183 
101 

Firsov S 
3.6 N 
109.8 E 
96 
64 
Name is on LAC
65 
Fizeau S 
58.7 S 
139.9 W 
62 
134 

Florensky 
25.3 N 
131.5 E 
71 
48 
Formerly
Vernadskiy B 
Fowler 
42.3 N 
145.0 W 
146 
34 

Fridman
(Friedmann) 
12.6 S 
126.0W 

89 
Should be shown
on Plate 6B, not 9B 
Frost 
37.7 N 
118.4 W 
75 
35 
Possibly
Nectarian 
Gagarin 
20.2 S 
149.2 E 
265 
102 

Galois 
14.2 S 
151.9 W 
222 
87 

Galois Q 
15.2 S 
154.7 W 
132 
87 

Garavito 
47.5 S 
156.7 E 
74 
119 

Gregory 
2.2 N 
127.2 E 
67 
65 

Gregory Q 
0.6 N 
125.7 E 
68 
65 

Guyot 
11.4 N 
117.5 E 
92 
65 

H. G. Wells 
40.7 N 
122.8 E 
114 
30 

Harkhebi 
39.6 N 
98.3 E 
237 
29 

Heaviside 
10.4 S 
167.1 E 
165 
85 

Heaviside K 
13.3 S 
168.5 E 
110 
85 

Helberg C 
23.4 N 
100.6 W 
70 
54 

Henyey 
13.5 N 
151.6 W 
63 
69 

Hess 
54.3 S 
174.6 E 
88 
132 

Hess Z 
52.0 S 
174.0 E 
73 
132 

Hirayama 
6.1 S 
93.5 E 
132 
82 

Houzeau 
17.1 S 
123.5 W 
71 
107 

Ibn Firnas 
6.8 N 
122.3 E 
89 
65 

Icarus D 
4.3 S 
171.2 W 
68 
86 

Idel'son 
81.5 S 
110.9 E 
60 
144 

Isaev 
17.5 S 
147.5 E 
90 
102 

Jeans 
55.8 S 
91.4 E 
79 
129 

Jeans N 
58.7 S 
90.5 E 
64 
129 

Joliot 
25.8 N 
93.1 E 
164 
46 
Possibly
Nectarian 
Joule L 
26.1 N 
144.1 W 
69 
52 

Jules Verne 
35.0 S 
147.0 E 
143 
118 

Keeler L 
13.3 S 
163.2 E 
71 
85 

Kidinnu E 
36.3 N 
124.5 E 
60 
30 

Klute 
37.2 N 
141.3 W 
75 
34 

Koch 
42.8 S 
150.1 E 
95 
118 

Kondratyuk 
14.9 S 
115.5 E 
108 
83 

Kramers 
53.6 N 
127.6 W 
61 
20 

Krylov A 
38.9 N 
165.1 W 
63 
33 

Kugler 
53.8 S 
103.7 E 
65 
130 

Lamb G 
43.2 S 
105.9 E 
69 
116 

Lampland 
31.0 S 
131.0 E 
65 
102 

Landau 
41.6 N 
118.1 W 
214 
35 

Langemak N 
12.9 S 
119.0 E 
126 
83 

Laue 
28.0 N 
96.7 W 
87 
54 
Possibly
Nectarian 
Lebedev 
47.3 S 
107.8 E 
102 
117 

Leeuwenhoek E 
28.2 S 
176.7 W 
117 
104 

Leibnitz 
38.3 S 
179.2 E 
245 
120 

Leucippus Q 
25.9 N 
118.8 W 
84 
53 

LeviCivita 
23.7 S 
143.4 E 
121 
102 

Lippmann 
56.0 S 
114.9 W 
160 
134 

Lodygin G 



106 
Renamed Sternfeld 
Lorentz 
32.6 N 
95.3 W 
312 
36 

Love 
6.3 S 
129.0 E 
84 
83 

Lundmark 
39.7 S 
152.5 E 
106 
118 

Mach 
18.5 N 
149.3 W 
180 
52 

Mandel'shtam 
5.4 N 
162.4 E 
197 
67 

McLaughlin 
47.1 N 
92.9 W 
79 
36 

McLaughlin C 
48.5 N 
91.9 W 
60 
21 

Mees Y 
15.7 N 
96.6 W 
85 
72 

Mezentsev 
72.1 N 
128.7 W 
89 
8 

Mezentsev M 
68.7 N 
126.8 W 
74 
8 

Milne 
31.4 S 
112.2 E 
272 
101 

Milne P 
37.1 S 
107.7 E 
95 
117 

Milne Q 
34.3 S 
107.3 E 
75 
117 

Mineur 
25 N 
161.3 W 
73 
51 

Minkowski 
56.5 S 
146.0 W 
113 
133 

Minnaert 
67.8 S 
179.6 E 
125 
141 

Mitra 
18.0 N 
154.7 W 
92 
51 

Montgolfier 
47.3 N 
159.8 W 
88 
33 

Morozov F 
5.4 N 
130.0 E 
60 
65 

Moseley 
20.9 N 
90.1 W 
90 
54 
Named on LAC 37 
Nassau D 
23.7 S 
179.2 W 
62 
104 

Nassau F 
24.7 S 
179.2 E 
112 
104 

Necho P 
6.8 S 
122.0 E 
75 
83 

Nishina 
44.6 S 
170.4 W 
65 
120 

Olivier N 
56.7 N 
137.1 E 
63 
17 

Omar Khayyam 
58.0 N 
102.1 W 
70 
21 

Oresme 
42.4 S 
169.2 E 
76 
119 

Oresme U 
41.6 S 
164.8 E 
84 
119 

Orlov Y 
22.8 S 
175.1 W 
126 
104 

Ostwald 
10.4 N 
121.9 E 
104 
65 

Pannekoek 
4.2 S 
140.5 E 
71 
84 

Pannekoek R 
5.4 S 
138.3 E 
71 
84 

Paracelsus 
23.0 S 
163.1 E 
83 
103 

Paracelsus E 
23.0 S 
167.2 E 
66 
103 

Paracelsus P 
24.9 S 
161.7 E 
63 
103 

Paraskevopoulos 
50.4 N 
149.9 W 
94 
19 

Paraskevopoulos
S 
49.1 N 
154.9 W 
67 
19 

Parenago 
25.9 N 
108.5 W 
93 
54 

Parkhurst 
33.4 S 
103.6 E 
96 
116 

Paschen 
13.5 S 
139.8 W 
124 
88 

Pasteur 
11.9 S 
104.6 E 
224 
82 

Pavlov M 
32.3 S 
141.8 E 
74 
118 

Perepelkin 
10.0 S 
129.0 E 
97 
83 

Planck 
57.9 S 
136.8 E 
314 
131 

Planck Z 
56.4 S 
135.2 E 
72 
131 

Poczobutt 
57.1 N 
98.8 W 
195 
21 

Poincaré 
56.7 S 
163.6 E 
319 
132 

Poinsot 
79.5 N 
145.7 W 
68 
8 

Polzunov 
25.3 N 
114.6 E 
67 
47 

Popov 
17.2 N 
99.7 E 
65 
46 

Prager 
3.9 S 
130.5 E 
60 
84 

Prager G 
4.6 S 
134.0 E 
76 
84 

Richardson 
31.1 N 
100.5 E 
141 
46 
Name is on LAC
29 
Roberts 
71.1 N 
174.5 W 
89 
7 

Röntgen 
33.0 N 
91.4 W 
126 
36 

RozhdestvenskIy 
85.2 N 
155.4 W 
177 
1 

RozhdestvenskIy
W 
84.8 N 
137.2 E 
75 
1 

Rumford T 
28.6 S 
172.1 E 
108 
104 

Rynin 
47.0 N 
103.5 W 
75 
36 

Saenger B 
5.6 N 
103.1 E 
64 
64 

Saha C 
1.4 N 
107.8 E 
64 
64 

Schlesinger 
47.4 N 
138.6 W 
97 
34 

Schlesinger B 
51.4 N 
134.9 W 
66 
20 

Seares 
73.5 N 
145.8 E 
110 
7 

Seidel 
32.8 S 
152.2 E 
62 
118 

Shayn 
32.6 N 
172.5 E 
93 
32 

Shternberg 
19.5 N 
116.3 W 
70 
53 

Sniadecki Q 
23.0 S 
170.1 W 
77 
104 

St. John 
10.2 N 
150.2 E 
68 
67 
Named on 66 
Stebbins 
64.8 N 
141.8 W 
131 
8 

Stefan 
46.0 N 
108.3 W 
125 
36 

Sternfeld 
19.6 S 
141.2 W 
100 
106 
Formerly Ladygin
G 
Stetson 
39.6 S 
118.3 W 
64 
122 

Störmer C 
58.3 N 
150.6 E 
61 
17 

Subbotin 
29.2 S 
135.3 E 
67 
102 

Szilard 
34.0 N 
105.7 E 
122 
29 

Teisserenc 
32.2 N 
135.9 W 
62 
34 

Thiessen 
75.4 N 
169.0 W 
66 
8 

Thomson 
32.7 S 
166.2 E 
117 
119 

Thomson M 
35.7 S 
166.0 E 
119 
119 

Tikhomirov 
25.2 N 
162.0 E 
65 
49 

Tikhov 
62.3 N 
171.7 E 
83 
18 

Titius 
26.8 S 
100.7 E 
73 
100 

Tsander 
6.2 N 
149.3 W 
181 
70 

Van der Waals 
43.9 S 
119.9 E 
104 
117 

Van Maanen 
35.7 N 
128.0 E 
60 
30 

Van't Hoff 
62.1 N 
131.8 W 
92 
20 

Ventris 
4.9 S 
158.0 E 
95 
85 

Vernadskiy B 



48 
Renamed
Florensky 
Vernadskiy X 
25.9 N 
129.0 E 
64 
47 

Vertregt 
19.8 S 
171.1 E 
187 
104 

Vestine 
33.9 N 
93.9 E 
96 
29 

Vetchinkin 
10.2 N 
131.3 E 
98 
66 

von Bekesy 
51.9 N 
126.8 E 
96 
16 

Von Karman 
44.8 S 
175.9 E 
180 
119 

Von Kármán M 
47.2 S 
176.2 E 
225 
119 
Name is on LAC
132 
Von Zeipel 
42.6 N 
141.6 W 
83 
34 

Watson 
62.6 S 
124.5 W 
62 
134 

Weyl 
17.5 N 
120.2 W 
108 
53 

Wiener K 
39.3 N 
147.8 E 
101 
31 

Wilsing 
21.5 S 
155.2 W 
73 
105 

Winlock M 
32.3 N 
106.0 W 
68 
36 

Wyld 
1.4 S 
98.1 E 
93 
82 

Yablochkov 
60.9 N 
128.3 E 
99 
16 

Yamamoto 
58.1 N 
160.9 E 
76 
18 

Zhiritsky F 
24.9 S 
121.6 E 
75 
101 

Zsigmondy S 
59.7 N 
106.7 W 
64 
21 

Zwicky 
15.4 S 
168.1 E 
150 
85 
Name is on LAC
103 
In the Nectarian System, two groups of basins help to define the system. Group 1 is relatively old: the Korolev and Moscoviense basins are within this group. If a crater judged to be in the Nectarian System is overlain by either of these basins, it may possibly be preNectarian, but it is not Lower Imbrian. On the other hand, if a crater judged to be Nectarian overlies one of the basins of the younger Group 2 (Crisium, Hertzsprung, Humboldtianum, or Mendeleev), it is possibly Lower Imbriam, but is not preNectarian. When a crater is partly covered by Imbrian ejecta (typically from either the Imbrium Basin or the Orientale Basin) it is difficult to judge its proper system. Of course, if it is partly covered by Imbrium ejecta it cannot be younger than Nectarian, and if partly covered by Orientale ejecta, it cannot be younger than Lower Imbriam, but still can be judged to be Nectarian.
Table 2.1 Nectarian System, Nearside, Plate 7A 

Feature 
Latitude 
Longitude 
Diam. (km) 
LAC 
Comments 






Abel B 
36.7 S 
82.8 E 
41 
116 

Abel L 
34.4 S 
82.6 E 
67 
116 
Partly covered
by Imbrian ejecta 
Abulfeda 
13.8 S 
13.9 E 
65 
78 
Partly covered
by Imbrian ejecta 
Adams 
31.9 S 
68.2 E 
66 
98 

Agatharchides P 
20.2 S 
28.7 W 
66 
94 
Flooded by mare 
Albategnius 
11.7 S 
4.3 E 
114 
77 
Partly covered
by Imbrian ejecta 
Aliacensis 
30.6 S 
5.2 E 
79 
95 
Partly covered
by Imbrian ejecta 
Almanon 
16.8 S 
15.2 E 
49 
96 
Partly covered
by Imbrian ejecta 
Alphonsus 
13.7 S 
3.2 W 
108 
77 
Partly covered
by Imbrian ejecta 
Amundsen 
84.3 S 
85.6 E 
101 
144 

Ansgarius 
12.7 S 
79.7 E 
94 
81 
Younger
than Crisium Basin 
Apianus 
26.9 S 
7.9 E 
63 
95 
Partly covered
by Imbrian ejecta 
Apollonius 
4.5 N 
61.1 E 
53 
62 
Younger than
Crisium Basin 
Aston 
32.9 N 
87.7 W 
43 
36 
Partly covered
by Imbrian ejecta 
Azophi 
22.1 S 
12.7 E 
47 
96 
Partly covered
by Imbrian ejecta 
Baco 
51.0 S 
19.1 E 
69 
127 
Possibly
PreNectarian 
Baco A 
52.8 S 
20.2 E 
39 
127 

Baco B 
49.5 S 
16.6 E 
43 
127 

Bailly 
66.5 S 
69.1 W 
287 
136 
Partly covered
by Imbrian ejecta 
Bailly A 
69.3 S 
59.5 W 
38 
136 

Bailly B 
68.8 S 
63.1 W 
65 
136 

Balboa 
19.1 N 
83.2 W 
69 
37 
Partly covered
by Imbrian ejecta, possibly preNectarian 
Ball 
35.9 S 
8.4 W 
41 
112 
Possibly
Lower Imbrian 
Ball C 
37.7 S 
8.7 W 
31 
112 

Barocius B 
44.0 S 
18.3 E 
39 
113 

Bartels 
24.5 N 
89.8 W 
55 
37 
Partly covered
by Imbrian ejecta 
Bayer 
51.6 S 
35.0 W 
47 
125 

Beaumont 
18.0 S 
28.8 E 
53 
96 

Behaim 
16.5 S 
79.4 E 
55 
99 

Bel'kovich A 
58.7 N 
86.0 E 
58 
15 
Younger than
Humboldtianum Basin 
Berosus 
33.5 N 
69.9 E 
74 
28 
Partly covered
by Imbrian ejecta, younger than Crisium Basin 
Berzelius 
36.6 N 
50.9 E 
50 
27 
Older than
Crisium Basin 
Biela 
54.9 S 
51.3 E 
76 
128 

Biela B 
56.5 S 
49.6 E 
43 
128 

Billy 
13.8 S 
50.1 W 
45 
74 
Partly covered
by Orientale ejecta; possibly Lower Imbrian 
Blancanus 
63.8 S 
21.4 W 
117 
125 

Blancanus C 
66.5 S 
28.0 W 
46 
137 

Bohnenberger A 
17.8 S 
40.1 E 
30 
97 

Borda 
25.1 S 
46.6 E 
44 
97 

Boss L 
50.9 N 
82.3 E 
40 
15 
Younger than
Humboldtianum Basin 
Boussingault A 
69.9 S 
54.0 E 
72 
138 

Brenner A 
40.4 S 
40.0 E 
32 
114 

Burckhardt E 
30.6 N 
55.7 E 
39 
44 
Younger than
Crisium Basin 
Byrgius 
24.7 S 
65.3 W 
87 
92 
Partly covered
by Imbrian ejecta 
C. Mayer B 
60.2 N 
15.6 E 
36 
13 
Partly covered
by Imbrian ejecta 
Cabeus B 
82.4 S 
53.0 W 
61 
144 

Cannon 
19.9 N 
81.4 E 
56 
45 
Older than
Crisium Basin, possibly preNectarian 
Capella 
7.5 S 
35.0 E 
49 
79 

Capuanus 
34.1 S 
26.7 W 
59 
111 
Partly covered
by Imbrian ejecta 
Catharina 
18.1 S 
23.4 E 
104 
96 

Cavendish 
24.5 S 
53.7 W 
56 
92 
Partly covered
by Imbrian ejecta 
Censorinus N 
1.9 S 
36.5 E 
36 
79 

Clavius 
58.8 S 
14.1 W 
245 
126 

Cleomedes 
27.7 N 
56.0 E 
125 
44 
Younger than
Crisium Basin 
Cleostratus 
60.4 N 
77.0 W 
62 
10 
Partly covered
by Imbrian ejecta 
Cleostratus F 
61.5 N 
80.4 W 
50 
21 
Partly covered
by Imbrian ejecta 
Colombo 
15.1 S 
45.8 E 
76 
79 

Colombo A 
14.1 S 
44.4 E 
42 
79 

Condorcet 
12.1 N 
69.6 E 
74 
62 
Younger than
Crisium Basin 
Condorcet F 
8.2 N 
73.1 E 
37 
63 
Younger than
Crisium Basin 
Condorcet P 
8.7 N 
70.4 E 
46 
63 
Younger than
Crisium Basin 
Cook 
17.5 S 
48.9 E 
46 
97 

Curtius 
67.2 S 
4.4 E 
95 
137 

Curtius B 
63.7 S 
4.7 E 
41 
126 

Cusanus 
72.0 N 
70.8 E 
63 
5 
Younger than
Humboldtianum Basin 
Cyrillus 
13.2 S 
24.0 E 
98 
78 

Cysatus 
66.2 S 
6.1 W 
48 
137 

de Gasparis 
25.9 S 
50.7 W 
30 
92 
Partly covered
by Imbrian ejecta 
De Sitter 
80.1 N 
39.6 E 
64 
1 

De Sitter A 
80.2 N 
26.6 E 
36 
1 

De Sitter M 
81.3 N 
38.5 E 
81 
1 

De Vico T 
18.7 S 
61.8 W 
41 
92 
Partly covered
by Imbrian ejecta 
Debes 
29.5 N 
51.7 E 
30 
44 
Younger than
Crisium Basin 
Debes A 
28.8 N 
51.5 E 
33 
44 
Younger than
Crisium Basin 
Deluc 
55.0 S 
2.8 W 
46 
126 

Demonax 
77.9 S 
60.8 E 
128 
139 

Descartes 
11.7 S 
15.7 E 
48 
78 
Partly covered
by Imbrian ejecta 
Doppelmayer 
28.5 S 
41.4 W 
63 
93 

Drebbel 
40.9 S 
49.0 W 
30 
110 
Partly covered
by Orientale ejecta, possibly Lower Imbrian 
Dubyago 
4.4 N 
70.0 E 
51 
62 

Eimmart 
24.0 N 
64.8 E 
46 
44 
Younger than
Crisium Basin 
Endymion 
53.9 N 
57.0 E 
123 
14 
Younger than
Humboldtianum Basin 
Endymion B 
59.8 N 
67.2 E 
59 
14 
Younger than
Humboldtianum Basin 
Epigenes 
67.5 N 
4.6 W 
55 
3 
Partly covered
by Imbrian ejecta 
Fermat 
22.6 S 
19.8 E 
38 
96 

Firmicus 
7.3 N 
63.4 E 
56 
62 
Younger than
Crisium Basin 
Fourier 
30.3 S 
53.0 W 
51 
92 
Possibly
Lower Imbrian 
Fourier A 
30.2 S 
49.5 W 
32 
93 

Fracastorius 
21.5 S 
33.2 E 
112 
97 

Fraunhofer C 
42.9 S 
64.7 E 
38 
115 

Furnerius Q 
39.5 S 