THE SOLAR SYSTEM
T
his is the ‘marine quadrant’, containing virtually the
whole of the Mare Imbrium and most of the Oceanus
Procellarum, as well as the Sinus Aestuum, Sinus Roris, a
small part of the Sinus Medii and a section of the narrow,
irregular Mare Frigoris. The Sinus Iridum, leading off
the Mare Imbrium, is perhaps the most beautiful object
on the entire Moon when observed at sunrise or sunset,
when the solar rays catch the top of the Jura Mountains
which border it. There are two prominent capes, Laplace
and Heraclides; the seaward wall of the bay has been
virtually levelled. It was in this area that Russia’s first
‘crawler’, Lunokhod 1, came down in 1970.
The Apennines make up the most conspicuous moun-
tain range on the Moon; with the lower Carpathians in
the south, they make up much of the border of the Mare
Imbrium. The Straight Range, in the northern part of
the Mare, is made up of a remarkable line of peaks rising
to over 1500 metres (5000 feet); the range is curiously
regular, and there is nothing else quite like it on the
Moon. The Harbinger Mountains, in the Aristarchus area,
are made up of irregular clumps of hills. Isolated peaks
include Pico and Piton, in the Mare Imbrium. Pico is very
conspicuous, and is 2400 metres (7900 feet) high; the area
between it and Plato is occupied by a ghost ring which
was once called Newton, though the name has now been
transferred to a deep formation in the southern uplands
and the ghost has been relegated to anonymity.AnaxagorasA well-formed crater with high walls and central
peak. It is very bright, and is the centre of a major ray-system,
so that it is easy to find under all conditions of illumination.
ArchimedesOne of the best-known of all walled plains; regu-
lar, with a relatively smooth floor. It forms a splendid trio with
Aristillus and Autolycus, which lie in the First Quadrant.
AristarchusThe brightest crater on the Moon. Its brilliant walls
and central peak make it prominent even when lit only by
earthshine; there are strange darkish bands running from the
central peak to the walls. Close by is Herodotus, of similar size
but normal brightness. This is the area of the great Schröter
Valley, which begins in a 6-kilometre (4-mile) crater outside
Herodotus; broadens to 10 kilometres (6 miles), producing the
feature nicknamed the Cobra-Head, and then winds its way
across the plain. The total length is 160 kilometres (100 miles),
and the maximum depth 1000 metres (3300 feet). It was dis-
covered by the German astronomer Johann Schröter, and is
called after him, though Schröter’s own crater is a long way
away in the area of Sinus Medii and Sinus Aestuum. Many TLP
have been recorded in this area.
BeerThis and Feuilléare nearly identical twins – one of the
most obvious craterlet-pairs on the Moon.
BirminghamNamed not after the city, but after an Irish astron-
omer. It is low-walled and broken, and one of several
formations of similar type in the far north; others areBabbage,
SouthandJohn Herschel.
CarliniOne of a number of small, bright-walled craterlets in the
Mare Imbrium. Others are Caroline Herschel, Diophantus,De
l’Isle and Gruithuisen.
CopernicusThe ‘Monarch of the Moon’, with high, terraced
walls and a complex central mountain group. Its ray-system
is second only to that of Tycho, so that at or near Full Moon it
dominates the entire area.
EinsteinA great formation in the limb region, beyond the low,
double and very reduced Struve. Einstein has a large central
crater. It is visible only under conditions of favourable libration
(and is not shown on the map) – as when I discovered it in
1945, using my 30-centimetre (12-inch) reflector.
EratosthenesA magnificent crater, with massive walls and
a high central peak; it marks one end of the Apennines, andCrater Diameter, Lat. °N Long. °W
km
Anaxagoras 52 75 10
Anaximander 87 66 48
Anaximenes 72 75 45
Archimedes 75 30 4
Aristarchus 37 24 48
Beer 11 27 9
Bessarion 15 14 37
Bianchini 40 49 34
Birmingham 106 64 10
Bode 18 7 2
Briggs 38 26 69
Cardanus 52 13 73
Carlini 8 34 24
La Condamine 48 53 28
Copernicus 97 10 20
De l’Isle 22 30 35
Diophantus 18 28 34
Encke 32 5 37
Epigenes 52 73 4
Einstein 160 18 86
Eratosthenes 61 15 11
Euler 25 23 29
Feuillé 13 27 10
Gay-Lussac 24 14 21
Gambart 26 1 15
Gérard 87 44 75
Goldschmidt 109 75 0
Gruithuisen 16 33 40
Harding 23 43 70
Harpalus 52 53 43
Helicon 29 40 23
Herodotus 37 23 50
Herschel, Caroline 13 34 31
Herschel, John 145 62 41
Hevelius 122 2 67Crater Diameter, Lat. °N Long. °W
km
Horrebow 32 59 41
Hortensius 16 6 28
Kepler 35 8 38
Kirch 11 39 6
Krafft 51 17 72
Kunowsky 31 3 32
Lambert 29 26 21
Lansberg 42 0 26
Lavoisier 71 36 70
Le Verrier 25 40 20
Lichtenberg 19 32 68
Marius 42 12 51
Mayer, Tobias 35 16 29
Milichius 13 10 30
Oenopides 68 57 65
Olbers 64 7 78
Pallas 47 5 2
Philolaus 74 75 33
Piazzi Smyth 10 42 3
Plato 97 51 9
Pythagoras 113 65 65
Pytheas 19 21 20
Reinhold 48 3 23
Repsold 140 50 70
Schiaparelli 29 23 59
Schröter 32 3 7
Seleucus 45 21 66
Sömmering 27 0 7
South 98 57 50
Struve 160 25 75
Timaeus 34 63 1
Timocharis 35 27 13
Ulugh Beigh 70 32 85
Xenophanes 108 57 77SELECTED CRATERS: SECOND QUADRANTis very like Copernicus apart from the fact that it lacks a
comparable ray-system. West of it is Stadius, a typical ghost
ring; it has a diameter of 70 kilometres (44 miles), but its
walls have been so reduced that they are barely traceable.
Probably the walls can be nowhere more than about 10 metres
(33 feet) high.
HeveliusOne of the great chain which includes Grimaldi and
Riccioli (in the Third Quadrant) and Cavalerius. Hevelius has a
convex floor and a low central peak; a system of rills lies on
the floor. West of Hevelius is Hedin, visible only under condi-
tions of extreme libration; it is 98 kilometres (61 miles) in diam-
eter, with irregular, broken walls.
KeplerA bright crater, and the centre of a major ray-system. Its
southern neighbour, Encke, is of about the same size, but is
much less bright and has no comparable ray-system.
Le VerrierThis and Heliconmake up a prominent crater-pair in
the Mare Imbrium, near Sinus Iridum.
LichtenbergA small crater which glows against the dark mare
surface. Unusual coloration effects have been reported here.
PlatoA large walled plain with fairly low walls, and an iron-
grey floor which makes it readily identifiable under any con-
ditions of illumination. There are a few craterlets on the floor,
some of which can be ‘missed’ when they ought logically to
be visible. Plato is perfectly circular, though as seen from Earth
it is foreshortened into an oval.
PythagorasWere it further on the disk, Pythagoras would be
truly magnificent, with its high, terraced walls and massive
central peak. Further along the limb, to the south, is the smaller,
similar but still very imposing Xenophanes.
TimocharisA well-marked formation with a central crater (a
peculiarity which it shares with Lambert). Timocharis is the
centre of a rather obscure system of rays.C Atl of Univ Phil'03stp 2/4/03 2:55 pm Page 57