Page 42 - Ultimate Visual Dictionary (DK)

THE UNIVERSE

The Moon TILT AND ROTATION OF THE MOON

Axis of Perpendicular to
rotation orbital plane
THE MOON IS THE EARTH’S only natural satellite.
It is relatively large for a moon, with a diameter Axial tilt
North of 6.7°
of about 2,155 miles (3,470 km)—just over a
Pole
quarter that of the Earth. The Moon takes the same
time to rotate on its axis as it takes to orbit the Orbital
plane
Earth (27.3 days), and so the same side (the near
THE MOON FROM side) always faces us. However, the amount of the
EARTH surface we can see—the phase of the Moon—
One
depends on how much of the near side is in sunlight. The Moon is dry rotation
and barren, with negligible atmosphere and water. It consists mainly takes 27 Earth
days and 8 hours South Pole
of solid rock, although its core may contain molten rock or iron. The
surface is dusty, with highlands covered in craters caused by meteorite
CRATERS ON OCEANUS PROCELLARUM
impacts, and lowlands in which large craters have been filled by
solidified lava to form dark areas called maria or “seas.” Maria occur
mainly on the near side, which has a thinner crust than the far side. Aristarchus
Many of the craters are rimmed by mountain ranges that form the
Cobra Head
crater walls and can be thousands of feet high.
(head of
Schröter’s
Valley)
De la Rue
NEAR SIDE OF THE MOON Aristoteles Herodotus
Hercules
Aristillus
Plato Atlas
Montes Apenninus
M A R E F R I G O R I S
Archimedes
Montes Jura Cleomedes
Sinus Iridum
Macrobius
Bright rays of Julius Caesar
ejected material M A R E I M B R I U M M A R E M A R E
S E R E N I T A T I S C R I S I U M
Copernicus
M A R E
Aristarchus
V A P O R U M M A R E M A R E
T R A N Q U I L L I TAT I S F E C U N D I T A T I S
O C E A N U S Langrenus
P R O C E L L A R U M
Kepler
Vendelinus
M A R E
N E C T A R I S
Encke
Cyrillus
Flamsteed
Petavius
Fra Mauro N U B I U M Fracastorius
M A R E
Furnerius
Grimaldi
Catharina
Letronne
M A R E
Rupes Altai
H U M O R U M
Gassendi
Albategnius
Mersenius
Ptolemaeus
Arzachel
Walter
Pitatus
Stöfler
Schickard Deslandres
Alphonsus Bailly Tycho Clavius Maginus
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